The Airbus safety magazine January 2016

#21 Safety first 002 Safety First #21 | January 2016

Safety fi rst Safety fi rst, #21 January, 2016. Safety fi rst is published by Airbus S.A.S. - 1, rond point The Airbus magazine contributing to the enhancement Maurice Bellonte - 31707 Blagnac Cedex/France. of the safety of aircraft operations by increasing knowledge Publisher: Yannick Malinge, Chief Product Safety and communication on safety related topics. Offi cer, Editor: Corinne Bieder, Director Product Safety Strategy & Communication. Concept Design by Airbus Multi Media Support 20152712. Reference: GS 420.0045 Issue 21. editorial Photos by Airbus, A. Doumenjou, H. Goussé, P. Pigeyre, A. Tchaikovski, Lindner Fotografi e. This brochure is printed on Stucco. This paper is produced in factories that are accredited EMAS and certifi ed ISO 9001-14001, PEFC and FSC CoC. It is produced using pulp that has been whitened without either chlorine or acid. The paper is entirely recyclable and is Safety fi rst is published by the Product Safety department. At this time of the year, discussions will start on the safety of produced from trees grown in sustainable forest It is a source of specialist safety information for the use the year that just ended. Everybody will set the objective to resources. of airlines who fl y and maintain Airbus aircraft. It is also do better than last year. And this is good. This very mindset The printing inks use organic pigments or minerals. There is no use of basic dyes or distributed to other selected organizations and is available is what allowed aviation for reaching today’s safety level. dangerous metals from the cadmium, lead, on tablets. mercury or hexavalent chromium group. When contemplating the future, it is often valuable to look Material for publication is obtained from multiple sources YANNICK MALINGE at the past. We ourselves went through this exercise and and includes selected information from the Airbus Flight revisited how the aviation industry got there. We believe SVP & Chief Safety Confi dential Reporting System, incident and accident that this historical overview can be of interest to others. investigation reports, system tests and fl ight tests. Material Product Safety Offi cer This is why we want to share it not only with the aviation is also obtained from sources within the airline industry, community but also with the public. Indeed, aviation safety studies and reports from government agencies and other is relevant to everyone, whether as a passenger, crew- aviation sources. member, potential traveller, relative of someone fl ying, or © Airbus S.A.S. 2016 – All rights reserved. citizen. Proprietary documents. All articles in Safety fi rst are presented for information By taking delivery of this Brochure only and are not intended to replace ICAO guidelines, Safety can never be taken for granted. Aviation safety has (hereafter “Brochure”), you accept on behalf of your company to comply with the following standards or recommended practices, operator-mandated a fascinating history of which we all together need to write guidelines: requirements or technical orders. The contents do not the next pages. No other intellectual property rights are granted supersede any requirements mand ated by the State of by the delivery of this Brochure than the right to read it, for the sole purpose of information. Registry of the Operator’s aircraft or supersede or amend I hope you will enjoy this video and fi nd it inspiring to further This Brochure and its content shall any Airbus type-specific AFM, AMM, FCOM, MMEL enhance safety. not be modifi ed and its illustrations documentation or any other approved documentation. May I take this opportunity to wish you and your relatives and photos shall not be reproduced without a very happy and safe New Year. prior written consent of Airbus. Articles may be reprinted without permission, except where This Brochure and the materials it contains shall not, in whole or in part, be sold, rented, or copyright source is indicated, but with acknowledgement licensed to any third party subject to payment. to Airbus. Where Airbus is not the author, the contents of This Brochure contains sensitive information the article do not necessarily refl ect the views of Airbus, that is correct at the time of going to press. neither do they indicate Company policy. This information involves a number of factors that could change over time, effecting the true public representation. Airbus assumes no obligation Contributions, comment and feedback are welcome. Enquiries to update any information contained in this related to this publication should be addressed to: document or with respect to the information described herein. Airbus S.A.S. shall assume no liability for any damage in connection with the use of this Airbus Brochure and of the materials it contains, even if Airbus S.A.S. has been advised of the likelihood Product Safety department (GS) of such damages. 1, rond point Maurice Bellonte 31707 Blagnac Cedex - France Fax: +33(0)5 61 93 44 29 The video is available on Airbus’ YouTube channel (www.youtube.com/airbus), Twitter account (www.twitter.com/ [email protected] airbus) and Facebook page (www.facebook.com/airbus). 002 Safety First #21 | January 2016

22nd Flight Safety Conference Bangkok, 21-24 March 2016

SAVE THE DATE NEWS

22nd FLIGHT SAFETY CONFERENCE – 2016

Another year has nearly passed since For any information regarding invitations, our last Flight Safety Conference please contact Mrs. Nuria Soler at in Paris. All the Airbus people who [email protected] were present enjoyed very much the opportunity to network with our This year, the two main themes will customers and to share ideas and be non-precision approaches and news. This was also confirmed by the evolving situation regarding all the feedback we received from skills, knowledge and experience. airlines delegates who valued this Our conference “journey” through great opportunity for sharing safety these topics will take us along the information. route of examining related incidents and accidents, how product design We are pleased to announce that the and operational procedures have 22nd Flight Safety Conference will take accommodated these aspects and place in Bangkok, Thailand, from the what best practice looks like from an 21st to the 24th of March 2016. airline perspective. As usual, there will be much to share and many The Flight Safety Conference provides opportunities to learn from each other. an excellent forum for the exchange of information between Airbus and its As always, we welcome presentations customers. from our operators. You can participate as a speaker and share your ideas To ensure that we can have an open and experience for improving aviation dialogue to promote flight safety safety. across the fleet, we are unable to accept outside parties. If you have something you believe will benefit other operators and/or Airbus The formal invitations with information and if you are interested in being a regarding registration and logistics, as speaker, please provide us with a well as the preliminary agenda have been brief abstract and a bio or resume at sent to our customers in January 2016. [email protected] 004 Safety First #21 | January 2016 Safety First #18 | July 2014 005

Safety first#21

PROCEDURES P06 Control your speed... in cruise

OPERATIONS P22 Lithium batteries: safe to fly? P42 Wake Vortices Flight operations

Maintenance AIRCRAFT

Engineering P52 A320 Family Aircraft configuration Ground operations 006 SafetyPROCEDURES First #21 | January 2016 Safety First #21 | January 2016 007 Control your speed... in cruise

Technically, cruising consists of heading changes and aircraft systems monitoring (fuel in particular), at a relatively constant airspeed and altitude. It ends as the aircraft approaches the destination where the descent commences in preparation for landing. Speed monitoring and control are crucial during this phase of fl ight to guarantee that the aircraft fl ies within its certifi ed fl ight envelope at all times, and any threats to the airspeed can be properly managed. This article will not immerse readers into the challenge of optimizing the aircraft performances in cruise, but it will aim at shedding more light on the existing threats to the airspeed during cruise, as well as good practices to best manage them. While planning their cruise to make the right speed and fl ight level choices, the fl ight crew needs to remain vigilant to speed excursions, and be able to recover if needed.

Control your speed… MANAGING YOUR CRUISE: NOTE UNDERSTANDING SPEEDS System descriptions and infor- mation included in this article in cruise are mainly referring to fl y-by-wire Speed in cruise is often driven by performances aircraft. However, the recommen- Third article in the “Control your speed” series started in and fuel burn considerations; however, Air Traffi c dations for speed management or weather considerations sometimes intervene remain applicable to all aircraft. issue #18 of this magazine, our aircraft is now fl ying in clean and require modifi cations to the optimum cruise confi guration, travelling in cruise. The main objective is to profi le.Whatever the fl ight crew’s decisions manage threats to the airspeed and avoid speed excursions. to best optimize their fl ight, one needs to be constantly aware of the applicable limits and maneuvering speeds. To safely manage the cruise phase within the aircraft certifi ed fl ight envelope, some characteristic speeds are useful references for fl ight crews to monitor the aircraft’s actual speed. What speeds exactly should be monitored? What do these speeds mean and what happens if they are ignored?

Many speeds are used to certify and reference speeds to safely guide the fl y an aircraft operationally. For every pilots navigation decisions through flight, the applicable characteristic the cruise phase. LORRAINE PHILIPPE speeds are computed automatically by DE BAUDUS CASTAIGNS the aircraft Auto Flight Systems (Flight Our objective is to highlight the Flight Operations Experimental Test Pilot Management System (FMS), Flight design and operational considerations Standards and Guidance (FG) and Flight Envelope underlying all recommendations Safety management (FE)) and displayed on the PFD Airbus has issued to flight crews airspeed scale. They are extremely regarding the monitoring of these useful as target maneuvering and limit speeds in cruise. PROCEDURES Safety First #21 | January 2016 009 Control your speed... in cruise

Maneuvering speed FIRST OR SECOND REGIME?

Green Dot was presented already We will see hereafter why pilots should At a given altitude, temperature, weight and thrust, fi gure 2 shows 2 points in the previous article dedicated to not routinely fl y slower than GD in cruise. of equilibrium where the thrust precisely compensates for the drag (thrust

the climb phase. Nevertheless, it = drag) and stabilized level fl ight is possible: point 1 (where CV is lower than is important to have this speed in For this reason, a recap of GD defi nition GD) and point 2 (where VC is higher than GD). Let’s have a closer look at the mind during the cruise phase as well, is provided hereafter, as well as the aircraft behaviour if the speed is moving away from these speeds: because it is a clearly visible reference consequences of fl ying slower than speed on the PFD airspeed scale. GD in cruise. • Point 2 is a stable equilibrium: in cruise, when the aircraft fl ies at this point 2, the airspeed is stabilized. Small variations of airspeed will naturally be compensated Green Dot (GD): best lift-to-drag ratio speed for and the aircraft will return to point 2. At point 2, the aircraft fl ies in thefi rst regime. Defi nition - If a disturbance increases the aircraft’s speed above point 2, then the drag increases. Consequently, the aircraft will decelerate back to the GD speed is the engine-out operat- It is represented by a green dot on equilibrium point 2. ing speed in clean configuration. It the PFD speed scale and displayed - If a disturbance reduces the aircraft’s speed below point 2, then the drag corresponds to the speed that allows only when the slats / fl aps control decreases. This generates acceleration and the aircraft’s speed will naturally the highest climb gradient with one lever is in the ‘0’ (CLEAN) position increase back to the equilibrium point 2. engine inoperative in clean confi gura- and landing gears are not com- tion. In all cases (all engines operative), pressed (fi g.1). • Point 1 is an unstable equilibrium: at this point, the aircraft fl ies in the the GD speed gives an estimate of second regime. the speed for best lift-to-drag ratio. - If a disturbance increases the aircraft’s speed above point 1, the drag reduces; GD therefore the aircraft will continue to accelerate until point 2. How is GD determined? - If a disturbance reduces the aircraft’s speed below point 1, then the drag becomes increasingly higher. If no action is taken, the aircraft will be ( fi g . 1 ) GD speed is computed by the Auto In cruise: naturally induced into a continuous deceleration. GD on the PFD speed scale Flight Systems (AFS) and is based To stop the deceleration and be able to accelerate again, two scenarii on the aircraft weight (thanks to the • Above GD, the drag and thrust are possible: Zero Fuel Weight (ZFW) inserted in the required to maintain speed increase When speed reduces below point 1 and remains higher than point 3: if FMS during fl ight preparation). The GD with the speed maximum thrust available is applied, then the aircraft can accelerate. formula has been set up so that the When speed reduces below point 3: there is no thrust margin available to resulting airspeed provides the best lift- • Below GD, the drag and thrust accelerate while maintaining a stabilized level fl ight. Then the only way to to-drag ratio for a given altitude, Mach required to maintain speed increase stop the deceleration is to lose altitude in order to accelerate beyond point 3. number and aircraft weight, in clean with speed decrease (second confi guration with one engine out. regime) (fi g.2). To sum up: • Faster than GD, the aircraft fl ies in the fi rst regime: it is stable with regards ( fi g . 2 ) to speed. Thrust curves and speed polar Thrust / Drag • Slower than GD, the aircraft fl ies in the second regime: it is unstable with regards to speed.

Region of reversed Drag command What are the operational implications of fl ying below GD? (second regime) Point 3 is not displayed on the PFD point 3 and eventually in a continuous Maximum thrust airspeed scale. Only GD is shown. deceleration. available The higher the aircraft, the lower Consequently, in clean confi guration in the maximum thrust available. This cruise, the crew should not fl y below GD. Given: Thrust means that at high altitude, close to REC MAX (RECommended Exceptionally, if flight slightly below - altitude MAXimum altitude), point 3 and GD GD is required for some reason, then - temperature are close to each other because the vigilant monitoring is necessary to GD IN A NUTSHELL - weight thrust margin is small. Therefore ensure that further uncommanded Do not fl y below GD V - thrust c fl ying below GD in level fl ight could speed reductions are immediately in cruise. 3 1 GD 2 easily drive the aircraft slower than checked and recovered from. PROCEDURES Safety First #21 | January 2016 011 Control your speed... in cruise

HOW IS THE REC MAX (RECOMMENDED MAXIMUM ALTITUDE) COMPUTED?

Looking more closely at the exact conditions limiting the altitude where a subsonic aircraft can safely fl y at, these can range from aerodynamic limitations to propulsion and certifi cation limitations.

REC MAX is the upper cruise limit: On Airbus aircraft, the REC MAX is always limited by the The following graph gives an illustrative example of the service ceiling or the certifi ed ceiling; with the exception above theoretical curves for an A320. This graph is used REC MAX = Min [Service ceiling; Aerodynamic ceiling; Max certifi ed ceiling] of A319 CJ aircraft and some versions of A340-500/600 by the FMS to determine REC MAX. aircraft at heavy weights. The schematic below applies to a heavy aircraft, which has a ceiling lower than the maximum certifi ed one.

FL Altitude (ft) A320-233 Speed envelope for GW = 70T ISA 39000 Absolute aerodynamic ceiling 38000 Max certi ed ceiling (ixed value) REC MAX ALT 37000 Aerodynamic ceiling 36000

Service ceiling 35000

GD Cost Index = 0 34000 33000 32000 MMO/VMO 31000 30000 29000

MD/VD Crossover FL 28000 27000 Maxspeed in level ight 26000 25000 24000 23000 0.5 0.52 0.54 0.56 0.58 0.6 0.62 0.64 0.66 0.68 0.7 0.72 0.74 0.76 0.78 0.8 0.82 0.84 0.86 Mach Mach

Stall limit (VS1g): this speed curve lowers with a weight Service curve, corresponding to the propulsion Green Dot increase. capacity of the aircraft’s engines to maintain + 300ft/ This curve provides a safety maneuver margin against minute at a constant Mach. Buffet (1,3g) the Stall limit curve. This curve increases with weight decrease and with

At low Mach, it starts at 1.23 x VS1g. static temperature decrease. Vz 300 ft/min At higher Mach, it corresponds to buffet onset of 1.3g

(corresponding to 40° of bank angle in level fl ight). Service ceiling (increases with weight decrease or VMO/MMO This curve lowers with weight increase. temperature decrease).

VMAX level at Max CLB Aerodynamic ceiling (increases with weight decrease). Maximum speed in level fl ight (in stable weather conditions with maximum thrust available in use) Econ speed CI = 0

Inaccessible domain (drag exceeds thrust), except if the aircraft is being subject to extreme weather conditions or enters a steep dive with maximum thrust. CI = 0 (Cost Index 0) is the point that gives the maximum rate of climb at a steady Mach. PROCEDURES Safety First #21 | January 2016 013 Control your speed... in cruise

Limit speeds THE CROSSOVER ALTITUDE

For a given weight, each aircraft has needs to be a safe margin in relation Aircraft normally fl y at an optimal IAS onset shock waves developing

a minimum selectable speed (VLS) and to these lowest and highest speeds, until they reach their optimal climb/ on the wings upper surface. maximum speed (VMAX) at a particular before the fl ight envelope protections cruise Mach. This transition between These shock waves significantly altitude. At the cruise altitude, there activate. airspeed and Mach occurs at a worsen the drag and can alter the point called the “crossover altitude” aircraft’s controllability. But this

V VLS: Lowest Selectable speed (usually between FL250 and FL300 phenomenon has nothing to do depending on the aircraft type). with buffet announcing lack of lift Defi nition When the aircraft climbs to the to come or an approaching stall. crossover altitude at a constant Airbus airplanes operated up to

VLS is the lowest selectable speed with VLS is indicated by the top of the amber IAS, Mach increases. The opposite VD/MD are not exposed to the A/THR engaged. Even if the target line on the PFD speed scale (fi g.3). happens when in descent to the so-called high speed buffet.

(fi g.3) speed is below VLS, the A/THR will crossover altitude, at a constant V on the PFD speed scale continue to target VLS. Mach. Then the IAS increases. • At high Indicated AirSpeed (IAS), At altitudes above the crossover the main threat to the aircraft

How is VLS determined? altitude, pilots will fly a Mach structural integrity lies in the GD and VLS number instead of an IAS because it dynamic pressure exerted by air on VLS is a characteristic speed computed Weight (ZFW) inserted in the FMS then becomes the most meaningful the structure. Aircraft controllability both depend on by the AFS as a function of the aircraft during fl ight preparation). parameter. remains optimum as long as the the aircraft weight, weight (dependent on the Zero Fuel Mach number is not too high. therefore these Different phenomena exist according VLS = 1.23 VS1g when in clean confi guration to the speed or Mach the aircraft In practice, the aircraft is designed speeds will be fl ies at. The aerodynamic world can to be safe up to Mach/speeds well wrong if the ZFW Where: therefore be split into two areas: low above VMO/MMO. Indeed, according to entered in the FMS and high Mach numbers. certifi cation requirements the aircraft VS1g is the stall speed demonstrated by fl ight tests. must be safe to fl y up to the design is wrong. • At high Mach number, when limit speed/Mach number VD/MD. Note: the 1.23 factor is applicable to fl y-by-wire aircraft (1.3 for the others). accelerating beyond MMO, slight In other words, up to VD/MD, the vibrations may appear. These are aircraft remains controllable and free

This formula means that VLS is higher since speed brakes extension vibrations due to unsteady early of any fl utter. when the speed brakes are extended, increases VS1g.

What are the operational implications of not respecting VLS?

How is VMO/MMO determined? Deliberately flying below VLS could aircraft, or expose the aircraft to a either lead to an activation of the Angle- stall if it is not protected, i.e. fl ying in a VMO/MMO is established with regards on Airbus aircraft, MD is usually equal Of-Attack protection on a protected degraded law. to the aircraft’s structural limits and it to MMO + 0.07 and VD approximately provides a margin to the design limit equal to VMO + 35 kt. speed/Mach number VD/MD. VD/MD VLS IN A NUTSHELL. must be suffi ciently above MOV /MMO The applicable VMO/MMO are indicated V to make it highly improbable that VD/ in each Aircraft Flight Manual. For VLS is the slowest speed the AFS lets you fl y MD will be inadvertently exceeded example, VMO/MMO and VD/MD are in normal law. in commercial operations. Several given in the following table. certifi cation criteria exist. As a result,

VMO/MMO: Maximum Operating speed/Mach number Aircraft type VMO (kt) MMO VD (kt) MD Definition A350 340 0.89 375 0.96

In cruise, in clean confi guration, MOV /MMO It is indicated by the lower end of the A380 340 0.89 375 0.96 ( fi g . 4 ) is the higher limit of the aircraft speed red and black strip along the PFD speed A330/A340 330 0.86 365 0.93 V on the PFD speed scale envelope. scale (fi g.4). A320 Family 350 0.82 381 0.89 A300-600 335 0.82 395 0.89 A310 360 0.84 420 0.90 PROCEDURES Safety First #21 | January 2016 015 Control your speed... in cruise

AoA These concepts involve understanding of the maneuver performed by test the maximum structural speed and pilots to determine these speed and Mach of the aircraft VD/MD. Mach.

VD is a Calibrated Air Speed (CAS). Key points to remember are: During test fl ights, VD/MD are reached • Reaching VD is much easier than by test pilots with the objective to reaching MD, demonstrate that the aircraft structural • At high altitude, reaching the aircraft’s integrity is not put at stake at these structural limit is almost impossible, speeds, and that the aircraft remains • At lower altitudes (i.e. below the α Max safely recoverable at all times. The crossover altitude), reaching VD article “High-altitude manual fl ying” that is possible because the available was published in the 20th issue of this thrust is higher, and drag due to α PROT magazine provides a good explanation Mach is lower. Mach At low What are the operational implications of not respecting VMO/MMO? (fi g.6) altitudes, the threat The JAR / FAR 25 rule dictates that • At lower altitudes, exceeding V MO Evolution with the Mach number of the AOA value triggering the α of exceeding VMO VMO or MMO may not be deliberately by a significant amount is a real Protection and α Maximum, in clean confi guration by a signifi cant exceeded in any regime of fl ight. The threat and can dramatically affect the parameter VMO/MMO basically sets integrity of the aircraft’s structure. amount is real and upper boundaries to the aircraft speed How are Vα PROT and Vα MAX determined? it can dramatically envelope. Although intentional VMO/MMO exceed- ance cases are rare, this limit speed Contrary to GD and VLS, Vα PROT and aircraft speed would be if it fl ew at an affect the integrity Vα PROT and Crews should keep in mind that can typically be overshot when the air- Vα MAX are not based on the aircraft Angle-Of-Attack (AOA) equal to α PROT of the aircraft’s • At high altitude, whilst it is important craft is subject to unusual wind and/ weight, as inserted in the FMS during (resp. α MAX). In fact, both speeds are Vα MAX are not to always respect MMO, a slight and or temperature gradient. Prevention is fl ight preparation through the ZFW. calculated on the basis of the aircraft structure. temporary Mach increase above that therefore essential. longitudinal equilibrium equation, along based on the

value will not lead the aircraft into an Vα PROT (resp. Vα MAX) as displayed on with the actual aircraft speed and AOA. aircraft weight. immediate hasardous situation. the PFD is a prediction of what the

Vα MAX = Vc x √(α-α0)/(αMAX-α0)

VMO/MMO IN A NUTSHELL Vα PROT = Vc x √(α-α0)/(αPROT-α0) VMO/MMO is the “never to exceed” speed. Where:

α0 is the AOA for a Lift Coeffi cient (CL) equal to 0. Flight envelope protection speeds: Vα PROT VC is the calibrated airspeed (CAS) is current AOA and Vα MAX α

On the A320 Family, Vα PROT and Vα MAX On A330/A340, A350 and A380 Defi nition can have different numerical values on Families, Vα PROT and Vα MAX have the both PFDs because VC comes from same numerical values on both PFDs.

Vα PROT is the speed corresponding to Vα MAX is the maximum Angle-Of-Attack different sources for left and right PFDs. the maximum Angle-Of-Attack (AOA) speed. It is the speed corresponding at which Alpha Protection becomes to the maximum Angle-Of-Attack active. It is only displayed in normal the aircraft can fl y at innormal law. Data source A320 Family A330/A340, A350 law and corresponds to the top of the It corresponds to the top of the solid and A380 Families black and amber strip along the PFD red strip along the PFD speed scale speed scale (fi g.5). (fi g.5). Left PFD: FAC 1, or FAC 2 if not Same value as the one used V available in FAC 1. by the fl ight controls. In practice, the AOA value of the VC Right PFD: FAC 2, or FAC 1 if not V Alpha Protection decreases as the α MAX is a function of the Mach number: available in FAC 2. Mach number increases. When the it decreases when the Mach increases AOA value of the Alpha Protection (fi g.6). AOA Same value used for PFD display as the one used (fi g.5) decreases, the Alpha Protection strip by the fl ight controls. V and V on the PFD speed scale on the PFD moves upward. PROCEDURES Safety First #21 | January 2016 017 Control your speed... in cruise

In order to avoid a fl uctuating αV PROT As a result of this fi ltering, a little delay MANAGING YOUR CRUISE: and Vα MAX display, AOA and VC values can be observed; therefore during a are fi ltered so that fast AOA variations dynamic maneuver, the aircraft may SPEED EXCURSIONS (for example during turbulence) do enter into a protection law with the

not pollute the PFD speed scale. IAS not yet below the displayed Vα PROT. OPERATIONAL

What are the operational implications of flying below Vα PROT? RECOMMENDATIONS 25 kt At any time during cruise, the actual threshold would immediately trigger the AOA is compared to α PROT (or α MAX) in high AOA protection, thus resulting in Understanding how the aircraft’s speed real time. The difference of AOA is then a nose down pitch rate ordered by the converted to speed and applied on fl ight control laws. Further increasing envelope is defi ned is essential to speed each PFD: the delta between current the AOA by maintaining full back stick excursion avoidance. Knowing the threats to ( fi g . 7 ) speed and V PROT (or V MAX) represents would eventually result in reaching the PFD display of the available speed margin α α airspeed and the tools at the crew’s disposal the actual margin against threshold. against α and α α PROT α MAX to tackle them is another part of that goal. This (or α MAX) (fi g.7). When fl ying in a degraded law, increas- ing the AOA would directly expose the includes knowing exactly which information In normal law, on a protected aircraft, aircraft to stall. should be looked at and how, with the aim to exceeding the AOA value of the α PROT acquire the best possible situational awareness and be able to avoid an overspeed (i.e. VMO/MMO exceedance) or a speed decay (i.e. reaching below VLS), and react wisely in case of an actual When fl ying Cruise speeds in a nutshell encounter. in a degraded law, increasing the Reading the fi rst section of this article • At lower altitudes (i.e. below the AOA would directly and understanding how VMO/MMO and crossover altitude), too large a VD/MD are determined highlighted that: speed decay can similarly lead a expose the aircraft Unknown domain non protected aircraft (i.e. flying to stall, like on At high altitude, reaching the aircraft’s in a degraded law) to enter a stall. any conventional structural limit Mach number is almost Nevertheless, at low altitude, the High speeds impossible (except in a steep dive available envelope is greater and the aircraft. with maximum thrust); therefore at thrust margin is much higher, thus high altitude, flying at high Mach providing fl ight crews a greater ability number should not be viewed as the to safely control the airspeed and biggest threat to the safety of fl ight. recover from a speed decay. On the Conversely, flying too slow (below other hand, at low altitude, reaching

Green Dot) at high altitude can lead to VMO and VD is possible; therefore high progressive reductions in speed until speed should be viewed indeed as a the protections are triggered. Should signifi cant threat to the safety of fl ight. Operational speeds Flight Tests this speed reduction take place in a degraded law, it could lead to a loss This chapter offers pilots background The biggest of control due to stall. At and near the knowledge of available prevention threat to the safety performance altitude limit of the aircraft, means in order to properly manage the range of available speeds between the main threats to the airspeed, and of fl ight both at Green Dot and MMO will be small. Speed eventually prevent an overspeed or a high and low decay at high altitude must be avoided speed decay thanks to anticipation and altitude relates to as a result. use of dedicated procedures. speed decay. Low speeds How to anticipate a speed excursion

Clearly fl ight crews are expected to be ones. In most cases, speed excursion Unknown domain able to rapidly scan the essential and situations are due to rapid wind and relevant parameters, in every situation, temperature variations/evolutions. in every fl ight phase, including dynamic PROCEDURES Safety First #21 | January 2016 019 Control your speed... in cruise

Gaining a good awareness of weather If the speed decreases further, then vibrations. Buffet is a clear sign of an the Angle-Of-Attack (AOA) must be approaching stall or even of the stall Weather is an important factor that The first key to preventing speed increased in order to increase the lift itself depending on its severity: it is

infl uences aircraft performances. Be it a excursion events is gaining awareness coeffi cient CL, which keeps the forces created by airfl ow separation and is a local fl ight or a long haul fl ight, decisions of the available weather predictions balanced. However, it is not possible function of AOA (fi g.8). based on weather can dramatically along the forecasted route. to indefi nitely increase the AOA. affect the safety of the fl ight. As it turns Before take-off, the weather briefi ng • At buffet initiation, the pilot starts out, the fi rst external threat to airspeed has to be as complete as possible. As per basic aerodynamic rules, the lift to feel airfl ow separation on wings

comes from weather disturbances, Pilots should check weather reports at coeffi cient LC increases linearly with the upper surface. such as turbulent areas that can lead alternate and destination airports and, AOA up to a point where the airfl ow to signifi cant speed changes. depending on the weather context, separates from the upper wing surface. • The buffet onset corresponds by Common sense generally makes this information needs to be updated If the AOA continues to increase, the defi nition to 1.3g (corresponding to pilots avoid those areas; however, they in fl ight as often as necessary. Weather point of airfl ow separation is unstable 40° of bank angle in level fl ight). sometimes end up in a situation where information can be communicated and rapidly fl uctuates back and forth. some solid turbulence is encountered, either by the Air Traffi c Controllers or Consequently, the pressure distribution • The “deterrent buffet” is so strong when dodging thunderstorms for by the other crews fl ying in the area. along the wing profile changes that any pilot will feel he/she needs example. At this point, the airspeed Once airborne, the weather radar constantly and also changes the lift’s to leave these buffet conditions. It begins to fl uctuate, thus making speed is one powerful tool to help the position and magnitude. This effect is corresponds to one of the defi nitions exceedance or speed decay more likely. crew make sound weather related called buffeting and is evidenced by of stall. Such situations need to be planned decisions to avoid adverse weather ahead and as far as possible, avoided and turbulence areas. through regular scanning of weather conditions and fl ight path adaptation.

Altitude and wind gradients: the main contributing factors

On aircraft with no failure, and the order to maintain altitude, and the A/THR engaged or the MAX CLB thrust pitch angle and the thrust values applied in manual mode, a continuous increase. Without suffi cient thrust speed decay during cruise phase may margin, the fl ight crew may notice be due to: that aircraft speed decays, but the • A large and continuous increase in REC MAX FL is not modifi ed. tailwind or decrease in headwind, in addition to an increase in the Outside The flight crew must be aware that Air Temperature (OAT), that results in at high altitude, the thrust margin a decrease of the REC MAX FL, or (difference between the thrust in use and the maximum available thrust) is • A large or prolonged downdraft, limited. The maximum available thrust when the fl ight crew fl ies (parallel decreases when there is an increase The nearer the ( fi g . 8 ) and) downwind in a mountainous in altitude and/or outside temperature. AOA effect on lift aircraft is to the area, due to orographic waves. The The REC MAX FL indicated in the FMS REC MAX FL, the downdraft may have a negative decreases when the OAT increases. vertical speed of more than 500 ft/ The nearer the aircraft is to the REC smaller the thrust min. Therefore, if the aircraft is in a MAX FL, the smaller the thrust margin. margin. downdraft, the aircraft must climb in When the AOA reaches a maximum These conditions should be avoided Stall is not value, the separation point moves fur- thanks to anticipation and regular scan- Preventing a speed decay: detecting ther forward on the wing upper surface ning of both the weather conditions a pitch issue and the phenomenon and almost total fl ow separation of the along the fl own route, and of the speed can happen at any upper surface of the wing is achieved: trend on the PFD. Nevertheless, these At any altitude, decreasing the speed signs of a signifi cant speed decay in this phenomenon leads to a signifi cant conditions might be approached unin- pitch. Stalling too much will certainly lower the aircraft’s order to be able to recover. loss of lift, referred to as a stall. Inci- tentionally. As soon as any stall indication is only an AOA level of energy and decrease margins for When speed decreases, pilots should dentally, stall is not a pitch issue and is recognized – be it the aural warning issue. maneuvering, thus potentially leading be attentive to their speed trend vector can happen at any pitch value. “STALL + CRICKET” or buffet – the to a loss of control due to stall with as displayed on the PFD and take aircraft’s trajectory becomes diffi cult to an aircraft fl ying in a degraded law. It action if an unfavourable speed trend control and the “Stall recovery” proce- is important to understand and detect develops in order to remain above GD. dure must be applied immediately. PROCEDURES Safety First #21 | January 2016 021 Control your speed... in cruise

NOTE Maintaining the aircraft after a VMO/MMO exceedance Any type of The fl ight crew must report any type of fl ight data allows to tell whether or not overspeed must A video illustrating buffet is presented in the tablet application of Safety fi rst for overspeed event (i.e. if the OVERSPEED an inspection is required. be reported by the this issue. warning is triggered). Indeed, in case fl ight crew. Only an of an overspeed, an inspection of the This supports the crucial need for fl ight aircraft structure may be required. crews experiencing an overspeed analysis of fl ight Indeed, when an overspeed event to report it! Then maintenance and data allows to tell occurs, the aircraft may experience a engineering teams will judge whether high load factor. Only an analysis of or not further inspection is needed. whether or not Approach to stall Stall an inspection is required. • Indications • Indications - Artifi cial stall warnings - Artifi cial stall warnings - Some natural stall warning indications - Natural stall warnings may be present - Buffeting - Lack of pitch authority - Lack of roll control • Progressive airfl ow separation - Inability to arrest descent

• Trajectory controllable with decreasing • Airfl ow separated from wing margin for maneuvering • Trajectory no longer controllable

Preventing and recovering from a VMO/MMO exceedance: dedicated procedures

Using dedicated procedures

As soon as an unfavourable speed following the operating techniques trend develops, pilots must take action and recommendations detailed in the and prevent a speed exceedance, OVERSPEED PREVENTION procedure. In cruise, the aircraft airspeed might not be the desired one at all times. The aircraft may encounter adverse weather and turbulences, or even winds, which all have a direct impact on the airspeed. For this reason, DID YOU KNOW fl ight crews must remain vigilant at all times and anticipate the main threats to the airspeed by planning ahead and communicating. On the A320 Family, speed brakes extension and retraction rates at high In practice, once the aircraft is airborne, pilots must be fully cognisant of Mach/Vc are roughly twice as slower Auto Pilot (AP) engaged compared with AP disengaged. As a consequence, if used to avoid a VMO/MMO exceedance, the airspeed as well as the speed trends at all times in fl ight. In case of crew should keep this in mind to retract them timely in order to avoid reducing need, the FCOM/QRH and FCTM provide procedures and adequate their speed below GD. This is particularly true when fl ying close to REC MAX. guidelines to prevent and to recover from a speed excursion, and react wisely to any variation of airspeed. They are worth being thoroughly read In most cases, the use of this The OVERSPEED warning is triggered and understood in advance. OVERSPEED PREVENTION procedure when the speed exceeds VMO + 4 will effectively prevent exceeding kt or MMO + 0.006, and lasts until VMO/MMO. Nevertheless, due to the speed is below VMO/MMO. In this system design and limited authority, case, the fl ight crew must apply the DID YOU KNOW this may not be sufficient. For this OVERSPEED RECOVERY procedure. reason, a OVERSPEED RECOVERY To know more about speeds, read our brochure “Getting to grips with aircraft procedure was developed as well and performance”, available on AirbusWorld. implemented in the FCOM /QRH. OPERATIONS Safety First #21 | January 2016 023 Lithium batteries: safe to fl y?

Lithium batteries are today’s power source of choice. As we become ever more reliant on Portable Electronic Devices (PEDs) to provide at your fi ngertips information, entertainment and communication, then so increases the demand for more powerful, yet lighter, sources of power. Hundreds of millions of Lithium batteries or equipment with Lithium batteries are carried on aircraft annually. These can be as part of passengers carry-on items, as aircraft (e.g. Portable IFE, defi brillators) or aircrew equipment (such as Electronic Flight Bags). They can be shipped as cargo in battery form or within other purchased items to support the demand for “just in time deliveries”, or indeed as power supply for aircraft equipment. Lithium batteries are becoming continually more common place in the aircraft environment. But the introduction of Lithium batteries included some highly visible cases of cell phones or laptops self-igniting and burning. Likewise, several events have occurred on aircraft, ranging from Lithium batteries: localized and limited fi res to large, uncontrolled in-fl ight fi res resulting in hull losses and fatalities. The air industry has become more aware of the specific safe to fl y? characteristics of Lithium batteries and the associated risks can now be mitigated. Procedures have been developed to address Today, Lithium batteries play a barely visible, yet essential the risks for Lithium batteries being part of the aircraft design, role in both our daily life and aviation alike. Manufactured and those belonging to passengers or crews carry-on items, or indeed handled correctly, Lithium batteries are safe. But production procedures linked to the shipping of Lithium batteries as cargo. failures, mishandling, or not being aware of their specifi c characteristics can have serious repercussions. LITHIUM BATTERIES: A POWERFUL AND VERSATILE TECHNOLOGY, ASSOCIATED WITH A COMMON RISK

Lithium is the metal with the lowest den- intrinsic risk is the same for all applica- sity, but with the greatest electrochemi- tions, different solutions and procedures cal potential and energy-to-weight ratio, exist to mitigate this common risk meaning that is has excellent energy depending on where and how the Lith- CHRISTINE BEZARD IAN GOODWIN PEIMANN PAUL ROHRBACH storage capacity. These large energy ium battery is used (i.e. part of the aircraft Head of Human Factors Director Flight Safety - TOFIGHI-NIAKI Fire Protection - density and low weight characteristics design, transported as cargo or in pas- & Ergonomics in design - Safety Enhancement Flight Safety Project leader Lithium make it an ideal material to act as a sengers and crews luggage and PED). Safety advisor Enhancement - batteries as cargo power source for any application where This section will highlight the benefi ts of weight is an issue, aircraft applications this new technology irrespective of its Flight Operations being a natural candidate. use in applications, and describe the and Training Support While the technology used and the associated risk of “thermal runaway”. OPERATIONS Safety First #21 | January 2016 025 Lithium batteries: safe to fl y?

Lithium: an increasing use Different types of Lithium batteries, different applications Experimentation with Lithium batteries powerful and durable batteries. began in 1912 and the first Lithium As it turns out, Lithium use in batteries batteries were sold in the 1970’s. In has been one of the major drivers of Different types ( fi g . 1 ) the nineties, Lithium battery technology Lithium demand since the rechargeable Forecast Lithium demand began to be widely used by a number Lithium-ion battery was invented in the Lithium batteries can take many forms. (usually rechargeable) batteries that can by application (Source: TRU Group) of industries that were looking for light, early nineties (fi g.1). They can be as tiny as single cell button act as high power energy sources for batteries – for example used as power electric vehicles, or indeed as back-up supply for watches – or multi cells power supply on-board aircraft (fi g.3). (fi g.3) Types of Lithium batteries: single / multi cells Lithium Consumption by End-Use

18,000 History and 2010-2020

16,000

14,000

ta in ed Batteries n

o 12,000 Li - c 10,000

t ion Different technologies 8,000 m p Glass Direct The term “Lithium battery” actually refers to a family of batteries that can be

on s u 6,000

C Other Alloy & Other divided into two categories: 4,000 Ceramics Glazing

2,000 Primary: Lithium-metal, non-rechargeable batteries ( fi g . 4 ) Lithium-metal batteries 0 These include coin or cylindrical Lithium-metal batteries have a higher 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Year batteries used in calculators, digital specifi c energy compared to all other cameras and emergency (back-up) batteries, as well as low weight and a Batteries Air Conditioning Al Process Add Ceramics Glazing Glass Direct applications for example (fi g.4). long shelf and operating life. Lubricants Pharmaceuticals Polymer Process Synthetic rubber Alloy & Other

Secondary: Lithium-ion / Lithium-polymer rechargeable batteries

Today, Lithium batteries are progres- The Lithium battery market is extremely Key current applications for this type of The advantages of the Lithium-ion sively replacing previous technology dynamic and expanding fast, with batteries are in powering cell phones, or Lithium-polymer battery are its batteries – e.g. Nickel-Cadmium, a growing application as the power laptops or other hand held electronic ability to be recharged in addition to (fi g.5) Lead-acid – and can be found in most source for a wide range of electric vehi- devices, as well as electric/hybrid cars its higher energy density and lighter Lithium-ion / Lithium-polymer batteries of electronic and autonomous electric cles. In fact, no level off is foreseen in and power stores (fi g.5). weight compared to nickel-cadmium systems or equipment. Development the coming years. In 2014, 5.5 billion and nickel-metal hybrid batteries. and applications are evolving with Lithium-ion batteries were produced latest uses including ultrathin (down to (fi g.2). 0.5 mm) and fl exible technologies.

( fi g . 2 ) Worldwide batteries production (Source: Christophe PILLOT, Avicenne Energy) OPERATIONS Safety First #21 | January 2016 027 Lithium batteries: safe to fl y?

One main intrinsic risk to tackle: the thermal Cathode Electrolyte Anode runaway current current collector collector As with every new technology, poorly manufactured, they can suffer Lithium batteries offer a number of stability issues and be subject to advantages, but they also come what is called a “thermal runaway”. with limitations. Although previous This phenomenon is well recognized batteries technologies were not risk- now, and it can be mitigated providing free, Lithium based batteries have awareness and prevention actions are a larger electrochemical potential; taken. Lithium therefore if damaged, mishandled or batteries can Cathode Anode be both a source A self-ignited and highly propagative phenomenon Passivating Layer of fi re through In case of internal degradation or Both the primary and secondary types of self-ignition and damage, a battery cell rapidly releases batteries are capable of self-ignition and Separator its stored energy (potential and chemical) thermal runaway. And once this process thermal runaway, through a very energetic venting reaction, is initiated, it easily can propagate and a cause which in turn can generate smoke, because it generates suffi cient heat to of fi re by igniting fl ammable gas, heat (up to 600°C and induce adjacent batteries into the same 1000°C locally), fi re, explosion, or a spray thermal runaway state. Abuse of fl ammable electrolyte. The amount of Lithium batteries can be both a source Thermal Runaway surrounding condition FIRE fl ammable energy released is directly related to the of fi re through self-ignition and thermal + electrochemical energy stored and the runaway, and a cause of fi re by igniting EXPLOSION material. type of battery (chemic and design). surrounding fl ammable material. Exothermic reaction and pressure built up

Internal degradation: breakdown of the thin Breakdown passivating layer in the electrolyte Internal damages: INSIGHT INTO THE THERMAL RUNAWAY PHENOMENON releasing ammable short circuits between hydrocarbon gases the electrodes A thermal runaway consists in an In multi-cell batteries, the thermal uncontrolled energy release. It refers runaway can then propagate to the to a situation where an increase in remaining cells, potentially resulting temperature changes the conditions in meltdown of the cell or a build-up The main factors contributing to a thermal runaway are: in a way that causes a further increase of internal battery pressure resulting in temperature, often leading to a in an explosion or uncontrolled fi re • Poor design or poor integration destructive result. of the battery. • Poor cell or battery manufacturing quality • Poor safety monitoring or protection • Poor handling / storage / packing conditions

DISCHARGE CHARGE V

EXTERNAL CAUSING OR ENERGIZING INTERNAL EVENTS ABUSE CONDITIONS OR EXOTHERMIC REACTIONS

External Heating

Li Charge Over-Charging Lithium Plating Electrode-Electrolyte Over-Discharging Reactions Leak ELECTROLYTE If Heating-Rate THERMAL High Current Charging Decompositions exceeds Dissipation-Rate RUNAWAY Smoke Flames Structural damage Electrochemical Li Discharge Reaction Crush Internal Short Circuit Gas Venting Explosion

Cathode Lithium salt + Anode External Short (Li Metal Oxide) organic solvent (Carbon) OPERATIONS Safety First #21 | January 2016 029 Lithium batteries: safe to fl y?

In-service experience

By their nature and properties, large In the cockpit as part of tablets numbers of Lithium batteries can be used for fl ight data support found in many places on-board an aircraft (fi g.6): In the cargo holds carried as cargo or in passengers baggage (fi g.6) In the cabin among the personal Lithium batteries on-board an aircraft effects of crews and passengers In the aircraft design.

Cameras Spare batteries Laptops AED Flashlights Tablets, MP3 FAA tests show that even a small hazardous materials, therefore par- Lithium number of overheating batteries emit ticular care and consideration must gases that can cause explosions and be taken to ensure safe operations in batteries ELT 21 1 2 3 4 5 6 7 8 9 10 11 12 fires that cannot be prevented by relation to use and transport of Lithium are classifi ed traditional fi re suppression systems. batteries (or devices containing In view of the possible consequences, Lithium batteries) when in an aircraft as hazardous Lithium batteries are classified as environment. materials. Cordless devices

4 8 9 ( fi g . 7 ) 20 12 21 2 5 10 19 Consequences of Lithium batteries 18 20 16 7 thermal runaway 14 19 1 3 6 11 13 17 15

CVR/DFDR 18

17 16 15 14 13 Damage to cabin overhead Hull loss Battery fi re compartment video camera Cell Phones A/C systems batteries HOW TO MITIGATE THE RISKS POSED BY LITHIUM BATTERIES

Since March 20th, 1991, the FAA The phenomenon of thermal runaway has recorded 158 incidents involving in an aircraft environment can be Although investigation into reported quite often it is unconscious abuse. batteries carried as cargo or baggage catastrophic. At the least it can range events highlighted that some Lithium Also, while strict regulations for according to their report on “Batte- from limited degradation of personal batteries fires were due to internal transporting Lithium batteries as ries & Battery-Power Devices – Aviation equipment, or minor damage to the short circuits relating to design, manu- cargo exist, several incidents have Cargo and Passenger Incidents overhead storage compartment. In the facturing or integration shortcomings, been related to Lithium batteries being Involving Smoke, Fire, Extreme Heat case worst situation, thermal runaway many – if not most – fi res were caused in the cabin. For this reason, a good or Explosion” dated 30 June 2015. in high density package of Lithium by abuse by the user. This may be awareness on risks posed by Lithium 81 of these events related to Lithium batteries can result - and has been deliberate or negligent abuse or phy- batteries of both airlines personnel and batteries. implicated - in hull losses (fi g.7). sical damage due to mishandling, but their passengers is crucial. OPERATIONS Safety First #21 | January 2016 031 Lithium batteries: safe to fl y?

The Lithium Permanently installed batteries batteries embedded Mitigating the risks posed by Lithium During an aircraft’s service life, this in the aircraft design batteries and preventing a thermal risk can be mitigated by adhering to Cameras Spare batteries Laptops Tablets, MP3 are subject to runaway or a fi re starts with securing common sense precautions, such the batteries that form part of the aircraft as using only the Original Equipment strict development design. In this respect, the Lithium Manufacturer (OEM) parts. The use and integration batteries embedded in the aircraft design of counterfeit or non-authorized parts 1 3 6 11 requirements, are subject to strict development and increases the risk of fi re and explosion. integration requirements, complying with Consequently, complying with the complying with the highest safety standards. The intrinsic Airbus Parts Catalogue and exclusi- the highest safety risk of this new generation of Lithium vely using Airbus or OEM catalogue Cordless devices based batteries is acknowledged at all references for spare batteries is key. standards. levels of the aircraft design phase, as Similarly, before installing spare 19 early as from the inception of the pro- batteries in Buyer Furnished Equipment duct and its systems. It is then mitigated (BFE) or in aircraft, operators should thanks to acceptability justification ensure the parts are genuine spare 19 1 3 6 11 based on each battery location, and a parts, that they have been stored and 17 15 thorough review of installation, ensur- handled appropriately and present no ing that no heat source and hazardous mark of overheat or damage. material or fl uids are in the vicinity.

DID YOU KNOW 17 15 Cell Phones

More information about the consequences on use of non-approved batteries can be found in OIT 999.0032/03 Rev 01, OIT 999.0035/04 and OIT 999.0145/14.

Carriage of Lithium batteries as air cargo

Increased usage of Lithium batteries batteries that can be shipped as AED Flashlights as the power supply of choice has, cargo on any single aircraft as a not surprisingly, led to an increase in cargo load. The only limitations are the shipping of Lithium batteries as air associated to what can be loaded cargo. Today, one of the main risks into each individual package. It is also ELT 21 8 9 posed by Lithium batteries is related worth understanding that these same to the shipping as freight. regulations are not intended to control The existing ICAO regulations do or contain a fi re within that packaging. not regulate the quantity of Lithium

What protection can the existing cargo compartment fi re protection 8 9 provide in the event of a Lithium battery fi re? 21 18 Today’s cargo fire protection of an Investigations have shown that the 13 aircraft is addressed by: cargo compartment fire protection • Passive protection (cargo hold linings standards described in CS/FAR25 are or protection of essential systems) not suffi cient to protect the aircraft from • Detection fi res involving high density shipments CVR/DFDR 18 • Suppression (use of Halon) or of Lithium batteries. 13 oxygen starvation “High density” describes a quantity of A/C • Preventing hazardous smoke / Lithium batteries that has the potential systems extinguishing agents into occupied to overwhelm the cargo compartment batteries compartments. fire protection system. In fact, the OPERATIONS Safety First #21 | January 2016 033 Lithium batteries: safe to fl y?

impact of different characteristics of tems are not capable of containing What the regulations say the batteries (e.g. chemistry, state of these accumulated gases. charge, size), cargo compartments The passive protection standards are In the light of the risks identified, in non-rechargeable and rechargeable Primary types and loading confi gurations make designed to withstand heat sources for January 2015, the ICAO Dangerous batteries alike. At time of publication it very difficult to define a quantity up to 5 minutes and are not resistant Goods Panel took the position to ban of this article, these discussions are (non-rechargeable) limitation that could be recommended against the characteristics of a Lithium the carriage of Lithium-metal batteries on-going. At their last meeting in Lithium-metal at aircraft level, for all operational battery fi re. The temperature, duration of all types, as cargo on passenger October 2015, the ICAO Dangerous situations. Tests have demonstrated and intensity of such a fi re will quickly aircraft. Goods Panel (DGP) proposed a 30% batteries are that some confi gurations, involving only overwhelm the passive protections. State of Charge (SoC) limit as an interim forbidden for one item of the regulated packaging In addition, the quantity and continuing However, whilst this was an important measure aiming to reduce the risk of fi re size, has the potential to lead to production of smoke produced is development, Lithium-metal batteries propagation to adjacent batteries and transportation signifi cant damage of an aircraft. likely to overwhelm the passive and only account for a small proportion of thereby improve aviation safety. aboard passenger- active smoke barriers that protect the all Lithium batteries carried annually as At the same time, discussions in carrying aircraft. Irrespective of the size of the shipment, occupied compartments. air cargo. Consequently, research into ICAO are focussing on establishing research into the impact of both Lith- the impact of a Lithium-ion batteries appropriate packaging and shipping ium-metal and Lithium-ion batteries With these findings, the aviation fi re has continued. As already noted, requirements to ensure safer shipment Today’s cargo fi re has demonstrated that the existing industry came to the conclusion that this research has demonstrated that of Lithium-ion batteries. Airbus is also cargo compartment fi re suppression today’s cargo compartments, which Lithium-ion batteries themselves involved in the Civil Aviation Safety compartments do systems – namely Halon 1301 (class are certifi ed to US CFR Part 25.857 and represent a signifi cant threat due to the Team (CAST) investigating overall not demonstrate C) or oxygen starvation (class E) – are EASA CS 25.857, do not demonstrate fact that the existing cargo compartment approaches from the battery itself to resistance to unable to stop a thermal runaway resistance to a fi re involving Lithium- fi re suppression functions are ineffective a combination of packaging / container and prevent propagation to adjacent metal and Lithium-ion batteries. For against a Lithium-ion battery fi re. and the aircraft itself. a fi re involving cells. If a thermal runaway is initiated, this reason, the inability to contain a The importance of correct trans- Lithium-metal heat and flammable gases coming Lithium battery fi re for suffi cient time As a result, regulatory authorities are port and shipping of Lithium batte- from the degradation of the hydro- to secure safe fl ight and landing of the now heading towards a larger ban on ries therefore becomes key, and and Lithium-ion carbon electrolyte will be emitted. aircraft, is an identifi ed risk to the air Lithium battery shipments as cargo on the involvement of the shipper and batteries. The existing fi re protection cargo sys- transport industry. passenger planes that would include operator is crucial.

CATEGORIZATION OF CARGO COMPARTMENTS

Cargo compartments of the Airbus fl eet • Class D compartments need to be are certified as class C and class E equipped with: compartments according to CS 25.857. - Ventilation control Additionally, some aircraft in service still - Fire resistant linings (passive have class D cargo compartments, but protection) this classifi cation was eliminated for - It needs to be demonstrated that new production in 1998. no hazardous quantity of smoke or fl ames are able to enter occupied • Class C compartments are required areas. for passenger aircraft compartments not accessible during fl ight (lower • Class E compartments are only deck) or if a fire could not be allowed for freighter aircraft. They controlled from the entrance point, need to be equipped with: without entering the compartment. - Smoke/fi re detection system A class C compartment needs to be - Ventilation control equipped with: - Only critical systems need to be - Smoke/fi re detection system protected from fi re - Ventilation control - It needs to be demonstrated that - Built-in fi re suppression system no hazardous quantity of smoke, - Fire resistant linings (passive fl ames or noxious gases are able protection) to enter occupied areas. - It needs to be demonstrated that no hazardous quantity of smoke, fl ames or fi re extinguishing agents are able to enter occupied areas. OPERATIONS Safety First #21 | January 2016 035 Lithium batteries: safe to fl y?

What shippers and operators can do: risk assessment and best practices

1. Check the latest industry available cable regulations (ICAO and/or local information and guidance regulations) • Overall capability of the aircraft and Air transport of Lithium batteries is its systems controlled by international and local • Segregation possibilities of Lithium regulations. If transporting Lithium batteries from other flammable/ batteries, operators need to first explosive dangerous goods. check the latest instructions for the Cameras Spare batteries Laptops Tablets, MP3 safe transport of dangerous goods 3. Ensure safe packaging and by air, be they provided through shipping Airworthiness Authorities or local regulations, and/or the ICAO. Local and/or international regulations provide the applicable set of rules 2 4 5 7 10 12 2. Perform a risk assessment that need to be complied with when transporting Lithium batteries. In the end, the responsibility for the Attention should be given to: safe carriage of dangerous goods Cordless devices (including Lithium batteries) lies • Training and awareness of employ- 4 with the shipper and operator. It is ees regarding: 20 12 recommended that if carriage of - The aircraft limitations against a 2 5 10 7 dangerous goods is pursued, then Lithium battery fi re and existing 20 16 a safety risk assessment of cargo mitigation means. 14 operations should be performed to - Regulations, handling procedures, determine if battery shipments can the dangers of mishandling, and be handled safely. methods to identify Lithium battery With respect to Lithium batteries, shipments. guidelines for the assessment should • Packaging: consider factors such as: - Clearly identify shipments of 16 14 Lithium batteries by information on Cell Phones • The quantity and density of Lithium airway bills and other documents. battery shipment - Make sure that the packaging is • The type of Lithium batteries to be correctly labelled and identified shipped as dangerous goods according • Who the supplier/shipper of Lithium to ICAO technical instructions. batteries is and their quality control - Do not ship damaged packages. • The identifi cation and notifi cation of • Cargo loading: segregate any all shipments of Lithium batteries Lithium battery shipments from (also Section II Lithium batteries) other dangerous goods that present • Accepting only Lithium battery a fi re hazard (fl ammable and explo- shipments that comply with appli- sive goods).

Carriage of Lithium batteries in the cabin

Whilst recent discussions have shifted The widespread use of Lithium DID YOU KNOW the focus towards the carriage of large batteries means that hundreds of quantities of Lithium batteries as cargo, Portable Electronic Devices (PED) are More information on the carriage of Lithium-ion batteries is provided in Airbus due to their proliferation and use in many likely to be carried on a large aircraft, ISI 00.00.00182 dated 24 July 2015. applications, operators need to also either in hold baggage or as carry on. Industry Guidance, such as the IATA “Lithium Batteries Risk Mitigation Guidance be aware of the risk of carrying Lithium Prevention is therefore essential to for Operators” also provides useful information for mitigating the risk on the batteries in passenger baggage – both raise passengers’ awareness of the carriage of Lithium batteries. checked in, off loaded cabin baggage risks associated to carrying Lithium and also carry-on cabin baggage. batteries. OPERATIONS Safety First #21 | January 2016 037 Lithium batteries: safe to fly?

Raising passengers awareness before boarding Mitigating the risks posed by Lithium batteries: summary Recommendations have been • Consider the quantity carried by developed with respect to what can individuals. Whilst there is no limit Lithium battery thermal runaways can • Ensure that loads conform with or cannot be carried in passenger on the number of PEDs or spare be caused by design / manufacturing ICAO / IATA labelling, packaging and baggage. ICAO and IATA regulated and batteries, below a specified size quality / integration shortcomings handling recommendations. recommended general requirements (normally 100 Watt-hour) that a or by inadequate compliance with a with regards to carrying and managing passenger or crew member may number of basic rules. The following • Ensure compliance to the Airbus what is carried in passenger baggage carry, but they must be for personal principles should be adhered to in Parts Catalogue when replacing is that: use. order to minimize the risk of Lithium batteries. battery fires and explosions: • Batteries carried should have been The key however is making both the • Ensure that ground, flight and cabin appropriately tested (e.g. should customer facing representatives and • Ensure that Lithium cells/batteries crews are trained and passengers be manufactured by the original the passenger themselves aware of shipped comply to international are aware of Lithium batteries spe- manufacturer). the risks presented by the incorrect standards. cificities. carriage of Lithium batteries, and • PEDs containing Lithium batteries making sure that they know the regu- should be carried in carry-on lations. To increase the awareness baggage. to the travelling public, posters and HOW TO MANAGE THE Lithium battery pamphlets can be a • Spare batteries (i.e. those not con- useful option and are widely used by CONSEQUENCES OF A LITHIUM tained in a PED), regardless of size, air carriers and authorities around the MUST be in carry-on baggage. They world alike. As an example, FAA have BATTERY FIRE are forbidden in checked baggage issued Safety Alerts for Operators and should be appropriately pro- (SAFO) number 15010, which deals tected against short circuit, e.g. by with “Carriage of Spare Lithium leaving the batteries in its original Batteries in Carry-on and Checked As detailed previously, proactive action fire is essential. The key principles to Halon can retail packaging. Baggage”. by making passengers and airline safely and efficiently tackling a Lithium personnel aware of the risks posed battery fire, whether it is in the cabin of suppress open Raising passengers awareness on-board by Lithium batteries is preferable than flight deck, being: flames, but it reacting to a fire caused by a Lithium • Keep people away from the fire is ineffective in A key aspect to mitigating the risk subsequent crushing of PEDs during battery. Therefore knowing what to do • Minimize risks of fire propagation is making the owner, namely the adjustment of the seat can lead to in the unlikely event of a Lithium battery • Apply specific firefighting principles. addressing the passenger, aware of the risks inherent overheat and thermal runaway. source of fire. Use to Lithium batteries being used in Making passengers aware of this Apply specific firefighting principles an aircraft environment. Make sure inherent risk can help reduce this of water is the best passengers are aware of what is scenario. For example, including a option to allow allowed in the terms of Lithium note in the pre-flight briefing to ensure Classical firefighting procedures and fire Halon can suppress open flames, but batteries in carry-on baggage, and the that in case a PED is lost, then the seat extinguishing means are not efficient to it is ineffective in addressing the source cooling and limit requirement for correct storage, but is not moved until the component is stop a lithium battery fire. of fire. Use of water is the best option to the propagation to also impact of a PED getting trapped retrieved is an option. Likewise, making allow cooling and limit the propagation adjacent cells. in the movable seat mechanism. cabin and flight crew aware of this to adjacent cells. potential failure mode is key to quick Due to their small size, PEDs can easily and efficient action when addressing Once a lithium battery cell has ignited be trapped in seat mechanisms. The a fire caused by a PED. then the effort must concentrate on cooling the surrounding cells by use of water (or other non-alcoholic liquid) and preventing deterioration of the situation to avoid any fire propagation to the INFORMATION adjacent battery cells. To this extent specific procedures that IATA has issued more information on the risk mitigations for operators on carriage of provide guidance on managing Lithium Lithium batteries. Visit their website (http://www.iata.org/whatwedo/cargo/dgr/Pages/ battery fires have recently been included lithium-batteries.aspx) for more information and guidance on different situations, mak- Fight Fight for both cabin crew (in the CCOM) and ing sure the last approved versions are used. the flames the heat flight crew (in the FCOM/QRH/FCTM). OPERATIONS Safety First #21 | January 2016 039 Lithium batteries: safe to fl y?

Cabin crew procedures a Lithium battery powered device may of Halon and liquid to tackle the fi re, be at the origin of the fi re. and makes reference to the other two Isolate the source of fi re Therefore the overhead bin smoke/ cabin crew procedures to address a fi re procedure now covers the use Lithium battery fi re. In the cabin, Reacting to a Lithium battery fi re in the a device that is emitting smoke. cabin starts with isolating the source Prevent propagation by ensuring ( fi g . 9 ) do not try to pick of fi re. Indeed, a smoking battery may that no fl ammable material (fl uids, Overhead bin smoke/ fi re CCOM up and attempt to explode at any time, due to the highly gas, devices) are near the smoking procedure exothermic thermal runaway. battery. Also relocate passengers move a burning In the cabin, do not try to pick up and away from the burning or heating device or a device attempt to move a burning device or device. that is emitting smoke. Fight the fi re according to specifi c procedures Once the burning / heating device deal with Lithium batteries fi res have has been isolated, the fi re itself needs been developed based on the FAA to be addressed. To this end, three recommendations. specific cabin crew procedures to

Lithium battery fire procedure

This procedure (fi g.8) proposes the merse the device in a suitable con- use of Halon to extinguish open tainer (such as a waste bin, or stand- fl ames, and water (or a non-alcoholicABNORMAL/EMERGENCY ard galley container) PROCEDURES to secure against liquid) to cool the device down. FIREthermal PROTECTION runaway (refer to the third A330/A340 ( fi g . 8 ) TheCABIN CREWrecommendation OPERATING MANUAL is then to im- step below). Lithium battery fi re CCOM procedure LITHIUM BATTERY FIRE

Ident.: 09-020-00015205.0001001 / 28 JAN 14 Criteria: LR Applicable to: ALL

The roles of the firefighter, assistant firefighter and communicator must be distributed according to the basic firefighting procedure. In the case of PED or spare lithium battery fire in the cabin or when notified by the flight crew:  If there are flames: FIREFIGHTING EQUIPMENT...... TAKE Consider the use of a PBE and fire gloves. HALON EXTINGUISHER...... DISCHARGE Halon extinguisher must be discharged to suppress the flames prior to cool down the PED or the Spare lithium battery.  When the flames are suppressed or If there are no flames: ON PED or spare lithium battery...... POUR WATER OR NON-ALCOHOLIC LIQUID The PED or Spare lithium batteries must be cooled down by pouring water or non-alcoholic Liquids STORAGE PROCEDURE AFTER A LITHIUM BATTERY FIRE ...... APPLY WARNING ‐ Do not attempt to pick up and move a smoking or burning device ‐ Do not cover the device or use ice to cool down the device. Ice or other materials insulate the device increasing the likelihood that additional battery cells will ignite. ‐ Do not use fire resistant burn bags to isolate burning lithium type batteries. Transferring a burning appliance into a burn bag may be extremely hazardous. END OF PROC

Overhead bin smoke/fire procedure

Lithium battery fi res may sometimes not occurred in service, the procedure easily be identifi ed, and considering the for fi re in the overhead compartment specifi c cases when fi res have actually (fi g.9) now considers as a base that

3DD A330/A340 FLEET 09-020 P 20/28 CCOM N 05 AUG 15 OPERATIONS Safety First #21 | January 2016 041 Lithium batteries: safe to fly?

Storage procedure after a Lithium battery fire • Once there are no more open flames: aimed at the device is sufficient to cool - If it is not possible to remove the it and mitigate the consequences of As referenced in the first step above, subject it to regular monitoring. burning/heating device from flight the thermal runaway. this procedure (fig.10) is called at the The lavatory is proposed as it contains deck, pour water or non-alcoholic - If it is possible to move the device: end of the two previous procedures. a means of smoke detection, but is liquid on the device to cool it down. transfer it to the cabin and use the Once the fire has been contained also a location that can secure the Be aware of possible explosion. Cabin Crew Lithium battery procedures and the device can be safely moved,ABNORMAL/EMERGENCY device away from PROCEDURES the passengers and Tests completed by Airbus have con- to secure it, by immersion in water or this procedure recommends to place provides waterproof floor designed firmed that a small quantity of water non-alcoholic liquid. FIRE PROTECTION receptacle where the burning/heating to receive water in case of turbulent A330/A340 deviceCABIN CREW was OPERATING immersed MANUAL in a lavatory and conditions. (fig.11) Smoke/fire from Lithium battery QRH (fig.10) procedure STORAGE PROCEDURE AFTER A LITHIUM BATTERY FIRE Storage after a Lithium battery fire CCOM procedure Ident.: 09-020-00015206.0001001 / 28 JAN 14 Criteria: LR Applicable to: ALL

 When the PED or the spare battery can be safely moved: FIRE GLOVES...... PUT ON RECEPTACLE...... TAKE Consider the use of any suitable empty receptacle (e.g. standard unit or lavatory waste bin ...) RECEPTACLE...... FILL WITH WATER OR NON-ALCOHOLIC LIQUID PED OR SPARE BATTERY...... IMMERSE Total immersion of the PED or the spare battery will prevent fire re-ignition. RECEPTACLE...... STORE INTO THE NEAREST LAVATORY LAVATORY...... SET AS INOPERATIVE AFFECTED LAVATORY...... MONITOR The affected lavatory must be regularly monitored for the remainder of the flight to ensure that the device remains immersed. END OF PROC

Flight crew procedure

More and more flying crews are taking The philosophy of the Airbus advantage of the capabilities offered “Smoke/Fire from Lithium battery” by Electronic Flight Bags (EFBs), procedure (fig.11) is: the majority of which use Lithium batteries as a primary power source. • One pilot needs to continue flying But Lithium batteries may also enter the aircraft, while the second pilot a cockpit in the form of a flashlight, will address the detected fire. DID YOU KNOW laptop, tablet, camera, mobile If necessary, transfer control. Usually phone,… i.e. any Portable Electronic the fire fighter is the one the closest To know more about Lithium battery fires management in the cabin, and cabin safety issues Devices (PEDs). to the fire. in general, read our brochure “Getting to grips with cabin safety”, available on Airbus World. With the aim to preventing a Lithium battery fire, the key is to ensure that the • Establish communication with the EFBs and other PEDs are not exposed cabin – a Lithium battery fire should Lithium batteries have existed for more than 20 years now and are widely Flight crew to abuse conditions (i.e. dropped or be managed as a whole crew con- procedures have damaged), and if damaged, not used cern – to initiate the “Storage after a used in all daily applications. This technology is extremely efficient and its until confirmed serviceable. However, if Lithium battery fire” procedure. 3DD A330/A340 FLEET 09-020 P 21/28 range of applications is constantly expanding. Whilst fortunately events been developed the feared situation occurs, flight crew CCOM O 05 AUG 15 involving Lithium batteries are rare, and even rarer when occurring in flight, on the basis of procedures have been developed • Secure the safety of the flight crew: key principles: on the basis of key principles: the Pilot Flying should don the oxy- the risk of fire still exists. The specificities of Lithium batteries need therefore Fly, Navigate, Fly, Navigate, Communicate, with gen mask, while the pilot that will to be considered in all aspects of aircraft applications and managed appropriate task sharing. tackle the fire should don the Porta- correctly – whether carried as cargo, or installed as equipment in the Communicate, ble Breathing Equipment (PBE). with appropriate flight deck or cabin, or just as part of the passengers carry-on baggage. • Use Halon to extinguish any open task sharing. flames. Article contributors include Joerg KLOCKGETHER and Dieter JUST. OPERATIONS Safety First #21 | January 2016 043 Wake Vortices

Where do Wake Vortices come from? All aircraft generate wake vortices, also Limited swirls exist also for the same known as wake turbulence. When an reason at the tips of the flaps. Behind aircraft is flying, there is an increase the aircraft all these small vortices mix in pressure below the wing and a together and roll up into two main depression on the top of the aerofoil. vortices turning in opposite directions, Therefore, at the tip of the wing, there clockwise behind the left wing (seen is a differential pressure that triggers from behind) and anti-clockwise behind (fig.1) the roll up of the airflow aft of the wing. the right one (fig.1). Development of wingtip vortices

------Low pressure ------+ + + + + + + + + + High pressure

Wake Vortices All aircraft generate wake vortices, also known as wake turbulence, which continue to be evident far behind the generating aircraft. Another aircraft crossing this wake may feel a sharp and brief turbulence which can be strong under some circumstances. Let’s review the specific characteristics of wake What are the characteristics of wake vortices? vortices’ and how pilots should react CLAUDE LELAIE Size: The active part of a vortex has a magnitude, in cruise, it could be 1000 ft in case of an encounter to ensure the Former Head very small radius, not more than a few below and behind the generating aircraft of Flight Test meters. However, there is a lot of energy at a range of around 15 NM. Then, safety of the flight. due to the high rotation speed of the air. when far away from the generator, the rate of descent becomes very small. In Descent rate: In calm air, a wake approach, the descent is usually limited vortex descends slowly. As an order of to around 700 ft. OPERATIONS Safety First #21 | January 2016 045 Wake Vortices

The decay However, depending on weather between aircraft needs to be so large. would have been a bit stronger behind signifi cant separations and dramatically The ICAO is much faster in conditions the descent rate may a Heavy. It is also common to have, in limit the traffi c on all airports and airways vary signifi cantly and may even be Ground effect: When the aircraft the initial approach phase, encounters at without significantly improving safety. separations ground effect. very small. One of the key factors is close to the ground, less than a distances well above the ICAO minimum It is also to be noted that statistics show have not been affecting this descent is the variation wingspan, the two vortices tend to drift separations. The ICAO separations have that the probability of injury to passengers of the temperature with the altitude. out from the centre line, each towards not been set to avoid all encounters but and crew is about fi ve times greater in set to avoid all A temperature inversion limits the rate its own side, at a speed of around 2 to prevent unsafe encounters. Avoiding turbulence due to weather, than with a encounters but of descent. to 3 kt. It is this phenomenon, when all encounters would require very wake vortex encounter. to prevent unsafe associated with a light crosswind Decay rate: One important parameter component that tends to “hold” the How does it feel to encounter a wake vortex? encounters. of a wake vortex is the decay of its “into wind” vortex roughly on the strength with time. The decay rate centreline, whilst the “downwind” In most cases the effect of the vortex is of the vortex, it will be subjected to varies slightly from one aircraft type to vortex moves away. mainly felt in roll. We will consider here the full strength of the vortex and roll another. Unfortunately, in calm air, due the case of an aircraft entering laterally in the same direction as the vortex, to to low external interference, it is rather Due to this phenomenon, the decay is in a vortex, which is the most frequent the left (fi g.2). This is the main rolling low and this is why the separation much faster in ground effect. situation. Let’s assume that a follower motion that creates the strongest roll aircraft is entering the right vortex of the acceleration. Parameters affecting the wake vortex leader aircraft from its right side. Seen from behind, this vortex is rotating anti- As a conclusion, the typical signature of Aircraft weight: Wake vortex strength It has also been demonstrated that clockwise. When the left wing of the a severe encounter is an initial small roll in increases with the weight of the aircraft. aircraft having a high inboard loading follower fi rst enters the vortex, there one direction followed by a much more This is why today the ICAO aircraft (higher defl ection of the fl aps close to is on this wing a local angle of attack signifi cant roll in the other sense. classifi cation is based on the MTOW. the fuselage as an example) have a increase and therefore the lift becomes However, such an approach is a faster decay of their vortices. higher than on the right wing. The initial When in cruise, this roll motion may be simplifi cation as other parameters also roll motion is therefore to the right. associated with signifi cant load factor affect the strength at the separation Weather conditions: The weather Then, when the aircraft is in the middle variations. distance. conditions play a major role in wake Calm weather vortex development and decay. In the ( fi g . 2 ) Wing characteristics: The wing shape case of heavy turbulence, a vortex will Aircraft behaviour in a wake vortex creates the most and the load distribution affect the wake dissipate very quickly and there is no risk encounter (The aircraft bank angle is critical situation vortex characteristics, mainly through for the “follower” aircraft. Strong winds voluntarily exagerated on the fi gure) the decay rate. are associated with turbulence and will as the strength also contribute to a rapid dissipation. decreases slowly A smaller wing span increases the decay rate. Therefore, for a given Calm weather creates the most critical and the vortex “vortex generator” or “leader” aircraft situation as the strength decreases effect may be felt weight and at the same distance, slowly and the vortex effect may be felt The typical far behind the vortex encounters are less severe far behind the vortex generating aircraft. signature of a severe behind an aircraft having a smaller Today, in order to be safe, all separations vortex generating wingspan. assume that the aircraft are flying in encounter is an initial aircraft. perfectly calm conditions. small roll in one direction followed Encountering a wake vortex by a much more signifi cant roll in the DEFINITIONS other sense. When an aircraft enters in the vortex of another aircraft, the “manoeuvre” is called an encounter. The aircraft emitting the vortex is called the generator Effect on the trajectory of the follower and the one experiencing it, the follower. To experience a severe roll encounter, When perpendicular, there will be no How likely is an encounter? it is necessary for the follower to have rotation, and any encounter will be a a trajectory with a small closing angle very brief but sharp turbulence effect. It is not possible to implement navigation in cruise, A319 vortices were identifi ed at with the vortex. However, if this angle is To experience a severe encounter, procedures such that the probability of a range of 42 NM, thanks to the contrails. too small, the aircraft will be smoothly the most critical angle between the an encounter is zero. To give an example, An encounter with such a vortex is “ejected” from the vortex (due to trajectory of the follower and the vortex during the Airbus wake vortex fl ight tests, obviously very weak but it exists and it the initial roll in the example above). is around 10 degrees. OPERATIONS Safety First #21 | January 2016 047 Wake Vortices

Severity of the encounters Use of rudder warning

The authorized separations are such when in ground effect, as explained A large defl ection of the rudder creates accident has already occurred for this that the severity of the encounters does above, the decay is much faster and a very important lateral acceleration reason. Some recent aircraft types are not create an unsafe control situation. the worldwide experience during many that may well surprise the pilot. It could protected thanks to their fly-by-wire When the aircraft is not in ground years shows that the bank angle lead to a reaction with a defl ection to systems, but anyway, any use of the effect, the order of magnitude of the achieved is much lower and does not the other side. This could then give rise rudder does not reduce the severity of bank angle for a severe encounter lead to a risk of touching the ground to very large forces on the fi n that may the encounter nor does it improve the on the approach is around 20°. But with the wingtip. exceed the structural resistance. An ease of recovery. Therefore:

Duration of an encounter DO NOT USE THE RUDDER A severe encounter, as described with the fl ight mechanics equations, it above, where the trajectories of both has been demonstrated during Airbus Lateral offset aircraft have an angle around 10 fl ight tests that the stabilization of a degrees, typically lasts around 4 to 6 large aircraft inside a vortex can only If two aircraft are fl ying exactly on the not a guarantee that an encounter will seconds. be obtained by voluntarily establishing same track, one being 1000 ft below be avoided (except if the vortices are a large sideslip angle. As airliners do the other, in the same or opposite clearly visible by contrails). It is not possible to remain for a long not and should not fl y with large sideslip direction, and if there is no cross wind, time in a severe vortex as the rotating angles, they cannot remain in a vortex. there is a risk of encounter with a vortex In case of cross wind, if the two aircraft airflow on the wing and on the fin, Therefore, a vortex cannot be the cause for the lower aircraft. In this case, it is are fl ying exactly on the same track, eject the aircraft from the vortex. In line of long duration turbulence. possible to reduce the risk by using a the wind will move the vortices out of lateral offset. the track of the lower aircraft whilst Operational procedures they are descending. In this situation, However, most of the time, it is diffi cult to if a lateral offset is decided for other General procedure increases know whether the other aircraft is fl ying reasons than wake vortex avoidance, with or without a small relative offset an offset upwind by the follower is to be Considering the way the vortex is clearly show that pilot action does not due to the lack of angular precision preferred, since a downwind one may acting on the aircraft as explained improve the situation. of the TCAS. Therefore, this offset is potentially create an encounter. previously, if the pilot reacts at the fi rst roll motion, to the right in the example In addition, in-flight incidents have Final approach given, he will correct by rolling to the demonstrated that the pilot inputs left. When in the core of the vortex, the may exacerbate the unusual attitude During the final approach, it has is already, today, the main cause main roll motion to the left will then be situation with rapid roll control reversals sometimes been suggested to of accidents and such a technique amplifi ed by this initial piloting action. carried out in an “out of phase” manner. maintain a trajectory slightly above the would only increase that risk. The result will be a fi nal bank angle glide slope. This is not a satisfactory greater than if the pilot would not have In the case of a severe encounter procedure for transport aircraft for As a conclusion, a transport aircraft moved the controls. the autopilot may disconnect auto- several reasons: should not deviate from the standard matically, but in all other cases, it will approach slope to avoid a risk This has also been demonstrated be able to counter properly the roll • When established in descent on the of encounter. However, for light during the Airbus fl ight tests. Most of and pitch motions generated by the standard approach slope, as the aircraft, with low approach speed, the encounters have been performed vortex. vortex is descending, there is little approaching on a long runway, it is stick free, but several hundred were risk of encountering the vortices of an acceptable procedure to perform carried out with the pilot trying to For these reasons, the best procedure the previous aircraft, except possibly a high approach and a long landing, minimize the bank angle. The results in case of encounter is: when reaching the area of the ground targeting a touch down point after effect. However, this possibility has that of the previous aircraft. not led to an unsafe situation (no accident in ground effect recorded It is to be noted that, when on an RELEASE THE CONTROLS on transport aircraft with standard approach, there is no risk of encounter Do not voluntarily disconnect the autopilot separations). with the vortices of an aircraft taking-off If the autopilot is disconnected, before any reaction, wait for a reasonable on the same runway as a vortex will only stabilization of the aircraft, then: • If the aircraft is fl own too high above move backward due to the wind effect. • Roll wings level. the threshold to avoid a possible Such a vortex will have a very limited • Re-establish the initial cruise level or the standard climb or descent encounter, it will lead to a long landing strength, and in the case of a strong trajectory. and therefore signifi cantly increase headwind may even be dissipated the risk of runway excursion. It is completely. However, with crossing well known that runway excursion runways, depending on their geometry, OPERATIONS Safety First #21 | January 2016 049 Wake Vortices

and with inappropriate procedures, it another runway. Pilots on the approach Other rules: The ICAO rules are used from A to F, A being the larger aircraft may be possible that, very close to the need to maintain a general vigilance worldwide except in two Countries, category. The principle is to divide ground, a landing aircraft enters the and awareness, especially with calm USA and UK. These two Countries the Heavies and the Medium each in vortex of an aircraft which took-off on wind conditions. apply a different classification with 2 categories. As an example, today, different weight limits and separations. the separations between Heavies Departure are established for the worst case RECAT (Re-categorization). that is the smaller Heavy behind the During the take-off phase, other obtain a minimum radar separation, bigger. However, if this bigger Heavy than time separation, no avoidance depending on the departure tra- Principles of the re-categorization: follows the smallest, common sense procedure is applicable as the jectory and long experience has The target of the re-categorization is indicates that a reduction of separation manoeuvre is dictated by characteristic demonstrated an acceptable level of to reduce the separations on approach is possible without any impact on speeds V1, Vr, V2, determined by the safety. and for departure between some the safety level (fi g.3). Similarly, the weight, the weather conditions and aircraft pairs, without degradation of separation may be reduced between the runway. The time separations For a light aircraft taking-off from the safety levels, in order to improve two big Heavies or two small Heavies. given for some aircraft types ensure a long runway behind a transport the landing capacity of a given runway The same principles apply to the that possible encounters after take- aircraft, it is recommended to choose or runway couple. Medium category. The target is that off remain controllable. When no time the departure point in order to achieve no situation should be worse than (fi g.3) separation is given by ICAO rules, the a trajectory well above the preceding The fi rst step is called RECAT 1. All that which exists today with ICAO Toward a reduction of aircraft separation separation is decided by the ATC to aircraft. the aircraft are placed in 6 categories separations. minima to aircraft categories Separations If this is safe... ICAO rules

Almost everywhere in the world the Approach: On approach, the sepa- separations comply with the ICAO rules. rations depend on the leader and the follower classifi cation. The table below 4 NM Classifi cations: Three categories of gives the separations for the various aircraft are defi ned according to the pairs on the same runway. They apply MTOW: also to operations on different parallel Heavy (H): above 136 tons. runways if they are separated laterally Medium (M): between 7 and 136 tons. by less than 760 m. To be noted that Light (L): below 7 tons. the A380 separations are not in the ICAO recommendations (PANS-ATM), In addition, despite being classifi ed but in a provisional State Letter pub- ...this is over conservative as Heavy, the A380 is known as lished by ICAO in 2008. Super (S), and subjected to increased separations in approach, behind. 4 NM Cruise: In cruise, the separations are identical for all aircraft types: Horizontally: 5 NM. Vertically: 1000 ft.

Follower

S H M L RECAT 1 FAA: The FAA decided to reclassify the aircraft by MTOW and S 6 NM 7 NM 8 NM wingspan. The RECAT FAA is implemented on several US airports.

H 4 NM 5 NM 6 NM RECAT 1 EU: It appeared that the RECAT FAA approach was giving few benefi ts Leader to the European airports due to the differences in the airlines fl eets on both sides M 5 NM of the Atlantic. A RECAT EU was therefore developed. It takes into consideration not only the strength of the wake vortex of the leader aircraft, but also the L resistance of the follower. The encounter tests performed by Airbus allowed validating some models used for the computations. OPERATIONS Safety First #21 | January 2016 051 Wake Vortices

The RECAT 1 EU has also 6 categories:

A - Super Heavy: Including A380 and An124. B - Upper Heavy: MTOW above 100 tons and wingspan between 52 m and 72 m. C - Lower Heavy: MTOW above 100 tons and wingspan below 52 m D - Upper Medium: MTOW between 15 and 100 tons and wingspan above 32 m. E - Lower Medium: MTOW between 15 and 100 tons and wing span below 32 m F - Light: MTOW below 15 tons.

The separations are as follows:

Follower Super Upper Lower Upper Lower Light Heavy Heavy Heavy Medium Medium

Super Heavy 3 NM 4 NM 5 NM 5 NM 6 NM 8 NM Upper Heavy 3 NM 4 NM 4 NM 5 NM 7 NM Lower Heavy 3 NM 3 NM 4 NM 6 NM Leader Upper Medium 5 NM Lower Medium 4 NM Light 3 NM

The RECAT EU was approved by EASA end 2014. The implementation is planned at Paris-Charles-de-Gaulle airport in February 2016 and it will also be implemented in some airports worldwide.

It is to be noted that this implementation is not intended to be mandatory and only the most important European airports will use it, the other ones will keep the ICAO separations.

RECAT 2 and RECAT 3: The RECAT 2 is also called “pair-wise”, with a separation that takes into consideration the leader and the follower types, possibly by groups of aircraft. It will be implemented in the coming years.

The separations are not meant to avoid all encounters but to prevent unsafe ones. In very calm air, wake vortices encounters may lead to strong turbulence with significant bank angle and possibly some load factor when at high altitude. Remember: Release the Controls and DO NOT use Rudder. 052 SafetyAIRCRAFT First #21 | January 2016 Safety First #21 | January 2016 053 A320 Family Aircraft confi guration

In 2009, a new data loading function was introduced on A320 Family aircraft Flight Control and Auto Flight systems computers. Although the operational improvements brought by Field Loadable Software (FLS) are widely appreciated, experience gained with them highlights a potential for aircraft confi guration mismanagement as a result of improper software part number uploading in the computers. A320 Family Aircraft In fact, the use of data loadable computers requires to manage not only hardware Part Numbers (PN), but also software PN and their combinations. This evolution calls for a change in mind confi guration sets and practices to properly manage FLS and data loadable computers confi gurations and in turn, the aircraft confi guration. SOFTWARE HAVE THEIR OWN PART TOO! This article will highlight the underlying safety aspects of an incorrect use of FLS and review how to best prevent it. With the introduction of a data loading function on A320 Family aircraft Flight Control and Auto Flight computers, managing the aircraft confi guration entered a new dimension. FIELD LOADABLE SOFTWARE: Flying a certifi ed aircraft now requires understanding not only WHAT IS IT ABOUT? hardware Part Numbers, but also less immediately visible operational software ones. Field Loadable Software (FLS) standards. Updating the standard associated with Data Loadable Units of a FLS can thus be done without (DLU), were originally introduced to removing the hardware itself from facilitate the evolution of standards aircraft. Indeed, it simply consists and the management of spares. in uploading the new version of the To do so, these computers provide operational software from a media an upgraded hardware that can disk to the same hardware, either accommodate different versions of directly on-board or using a portable operational software, i.e. different data loader. On the Are all A320 Family aircraft concerned? existing A320 Field Loadable Software started to hardware without using the aircraft Family fl eet, some be introduced progressively on the data loading function. In that case, the aircraft have FLS, UWE EGGERLING ALEXANDRE LAGU A320 Family around six years ago. hardware needs to be fi tted upstream In practice, on the existing fl eet, some in a repair shop, with the adequate others don’t. Senior Director Safety Flight control systems aircraft have it (either from delivery operational software version. The DLU Yet, all aircraft Engineering and Senior engineer or via Service Bulletin), others don’t. loaded with the relevant Field Loadable Maintenance However, even the non-equipped Software standard then behaves as a can accommodate aircraft can accommodate a DLU non-loadable computer. DLUs. AIRCRAFT Safety First #21 | January 2016 055 A320 Family Aircraft configuration

What does the data loading function WHAT IF THE AIRCRAFT change in practice? FLIES WITH INAPPROPRIATE If a DLU loaded with the appropri- a new, intangible and not immediately ate standard behaves exactly as a visible dimension. OPERATIONAL SOFTWARE? non-loadable computer, whether it is Indeed, with the disconnection installed on an aircraft with the data between hardware and operational OR WHEN INAPPROPRIATE loading function or not, the use of this software introduced by Data Loadable new DLU introduces a major change Units, the aircraft configuration con- OPERATIONAL SOFTWARE in terms of spares and aircraft configu- sists of physical parts PN as well as ration management: the emergence of operational software PN. CAN LEAD TO A NON-CERTIFIED A quick AIRCRAFT CONFIGURATION… glance at the hardware installed cannot tell No one would install an incorrect operating such configurations, whe- hardware PN on the aircraft as the ther immediate or not, could not be everything about aircraft would then be in a non-certified studied and tested because explor- the FLS standard, condition, with all the potential safety ing them falls de facto outside of the consequences it could have. Flying with design studies. However, they do exist and in turn, the incorrect operational software comes to and can take on a potential significant actual aircraft the same thing! safety dimension. configuration. Indeed, uploading an operational The cases that were observed in ser- software into a hardware which is not vice are good examples to reveal that supposed to receive it, leads to a non- consequences are varied and may Non-DL ELAC DL ELAC certified aircraft configuration. This actually impair safety in very different implies that the consequences of ways. In practice, it means that a quick glance at the hardware installed is not sufficient to identify the FLS standard, and in turn, the actual aircraft configuration. Case 1: Excessive structural loads - unknown structural fatigue

Sharklet aircraft include a new Load losing this LAF function, thus exposing Alleviation Function (LAF) that allows the wing to non-anticipated and studied to limit wing loads. This function is loads. If the consequences cannot key to ensure that wing loads remain be detected immediately, such non- within certification requirements. certified configuration leads to structural Fitting a Sharklet aircraft with a pre- loads and ultimately structural fatigue Sharklet ELAC (ELevator and Aileron that have not been studied as such, Computer) and/or SEC (Spoiler & but could ultimately result in safety Elevator Computer) standard leads to concerns.

Case 2: Falsely relying on a safety enhancement not implemented on the aircraft

In order to reduce the likelihood of tail with ABS system whereas it does not strikes or hard landings, new ELAC have the function. standards were developed with an improved transition flare law to ground Similarly, ROPS (Runway Overrun law. Flying with an aircraft supposed Protection System) is only available to be fitted with these new computers with the latest loadable FAC (Flight and actually fitted with an ELAC Augmentation Computer) standard. standard prior to these improvements Installing an older software on a leads to a situation where pilots believe ROPS-capable aircraft would lead they benefit from these improvements to loose this safety enhancement whereas they actually don’t. It is like function and the crew would not be driving a car believing it is equipped aware of it. AIRCRAFT Safety First #21 | January 2016 057 A320 Family Aircraft configuration

Case 3: Improper surfaces control and unexpected aircraft behavior configuration at all time. Prevention starts with a good awareness of the most common factors that On Sharklet aircraft, in case Sharklet capable and non-Sharklet capable FLS can contribute to having a DLU loaded with an are mistakenly mixed (knowing that this is a non-allowed and non-certified undesirable operational software. configuration), the behaviour and control of the aircraft might be impaired. Depending on the type of DLU concerned, possible consequences are: The investigation into reported events of step requested in the AMM installation • Mix of Sharklet capable and non- - Left and right Aileron surfaces syn- improper operational software uploaded and uploading tasks. Sharklet capable ELAC/SEC chronisation not properly applied into Data Loadable Units highlighted a Spoiler, Aileron and/or Elevator Sur- as expected (might lead to Air- variety of initial contributing factors. Being convinced of having installed face actuator orders and monitoring craft unexpected behaviour). Yet, they all have in common a major the correct FLS standard although not provided by each ELAC/SEC might step being overlooked in the computer having it, can in turn come from different CAUTION be different from one actuator to • Mix of Sharklet capable and non- removal/installation AMM procedure: reasons, such as: This equipment the other (as controlled by different Sharklet capable FAC operational software identification requires eld loadable software. units). Installing a non-Sharklet capable through a LRU IDENTIFICATION check • not having realized that the DLUs Ensure correct This may result in: FAC on a Sharklet aircraft may lead (LRU stands for Line Replaceable Unit)! consist of two distinct parts, namely software is loaded. Refer to AMM - Force fighting in case of elevator to erroneous characteristic speeds a hardware one and a software one, double pressurisation (might lead computation, which, in turn, may When operating FLS, strict adherence bearing 2 distinct Part Numbers and 2 to structural defect and/or Aircraft affect safety margins against the to all of the steps detailed in the AMM FINs (Functional Item Number), unexpected behaviour) stall speed. removal/installation tasks, and the LRU IDENTIFICATION step in particular, • being excessively confident in the These cases are not an exhaustive list of the safety related consequences that is the foundation of a good aircraft shop that delivers the parts to be Unexplored may result from an erroneous combination of a DLU hardware loaded with the configuration management. installed (the DLU received from the undesirable operational software standard. Some of the effects described are shop might not be loaded with the safety related potential effects based on a purely theoretical analysis since these configurations In more detail, investigation results relevant operational software, i.e. the consequences does have never been tested. However, unexplored safety related consequences highlighted that installing a DLU one that matches the actual aircraft does not mean no safety consequences! loaded with inappropriate software configuration), not mean no safety often results from the combination of consequences. With this in mind, the key question is: how to avoid installing a Data Loadable being convinced to have the correct • relying on the spot on an old habit Unit with an inadequate FLS standard? computer although not having it, and where a quick external glance not taking the time to perform the at physical parts and their labels procedure correctly, especially the was sufficient to tell the computer DID YOU KNOW operational software identification standard.

ISI (In-Service Information) Ref. 27.93.00001 “ELAC mixability and interchangeability matrices” details how to manage data loadable units and Using existing safety barriers associated Part Numbers. This document can be found on Airbus World.

PREVENTION: HOW TO AVOID INSTALLING A DATA LOADABLE UNIT WITH AN INADEQUATE OPERATIONAL SOFTWARE STANDARD?

In view of the potential operational consequences described earlier, Operators need to be cautious As explained earlier, the introduction of configuration management. In contrast with FLS and DLUs management in order to Field Loadable Software comes with a to hardware parts, operational software change in philosophy and the emergence are always hosted. They are the invisible ensure their aircraft are operated in a certified of a new intangible dimension in aircraft ones, behind the scene. AIRCRAFT Safety First #21 | January 2016 059 Customer : KAC Manual : AIPC A320 Family Aircraft confi guration Type : TF-N Selected applicability : ALL Rev. Date : May 01, 2015 27-93-08-03C - EQUIPMENT INSTL

Customer : KAC Manual : AMM Type : TF-N Selected applicability : ALL ** ON A/C 051-100 Rev. Date : May 01, 2015 27-93-00-200-001-A - Check of the reference of the software loaded in the ELAC 27-93-08-03C-EQUIPMENT INSTL Concerning the parts managed by the induces diffi culties to ensure that the FurtherZone(s): 120 enhancing prevention… shop, the disconnection between the computer delivered is loaded with FIG - ITPART NUMBER NOMENCLATURE FIN UNIT PER ASSY B. Make sure that this(these) circuit breaker(s) is(are) closed: EM ACCESS/PANEL hardware and the operational software the appropriate operational software The 03Cin-depth 01 NAS1102-3-8 analysis of.SCREW reported events allowed for better understanding008 where for DLUs alsoPANEL implied switchingDESIGNATION from a version. FIN LOCATION problems0 originated from, and thus for devising ways forward. 49VU FLIGHT CONTROLS/ELAC1/NORM/ 15CE1 B11 03C 02 NAS1726-3E .NUT 016 unique computer FIN SPLYintegrating both 0 the hardware49VU and softwareFLIGHT parts, CONTROLS/FCDC1/SPLY to two In any case,20CE1 an ultimateB10 safety barrier was As of03C today, 03 NAS1096-3-10 the available.SCREW prevention aircraft confi guration.008 This advice is 49VU AUTO FLT/MCDU/1 11CA1 B01 0 distinct FINs105VU correspondingFLT CTL/ELAC1/STBY respectively SPLY developed16CE1 and A01included into the AMM measures03C 04 AN960-10L include: .WASHER provided on the understanding008 that to the hardware PN and the operational to prevent the installation of improper 0 an ISI is not an approved instruc- ** ON A/C 001-049 03C 05 F0003058200000 .RACK 2CE1X, 2CE2X 002 software 121VUPN. In some airlinesAUTO FLT/MCDU/2 though, the operational11CA2 softwareN20 onto the aircraft: • The0B improvement of the IPC to tion; therefore once a confi guration spare parts** ON supply A/C 001-049, chain 101-199 management operational software identification via include explicit content and reinforce is identifi ed by this means, the IPC Spare ABS1699-06 .RACK ASSY 121VU FLIGHT CONTROLS/FCDC2/SPLY 20CE2 Q20 tool remained unchanged and does not LRU IDENTIFICATION action and cross awarenessPart on FLS (fi g.2). must be checked in order to confi rm 121VU FLIGHT CONTROLS/ELAC2/NORM/ 15CE2 R20 accommodate two differentSPLY FINs for a check of that information with the PN ** ON A/C USED WITH F0003058200000 that it is a certifi ed one indeed. single FLS** ON computer. A/C 101-199 This limitation displayed on the media disk (fi g.1). • The 03C improvement 05 NAS1102-06-6 of ..SCREWthe ISI (In-Ser- 004 5 121VU AUTO FLT/MCDU/2 11CA2 N19 vice03C Information) 05 ASNA2168-01 documentation..LATCH as a • The introduction in the002 Field Loada- ** ON A/C 001-049, 101-199 support6 for your fl eet management. ble Software training on A320 Family ( fi g . 1 ) 4. Procedure This** ON document A/C 051-100 offers a good over- aircraft, of more details on the rec- Preventing the installation of an improper Subtask 27-93-00-280-052-A view03C 06of NAS1100-06-7existing certifi.SCREW ed confi gura- ommended uploading016 procedure, ELAC operational software onto the A. Do a check of the reference of the software loaded in the ELAC 0 aircraft thanks to the AMM tions03C by07 MS21042L06 explicitly explaining.NUT the hard- as well as a reminder of016 these DLUs NOTE: This procedure is for the ELAC1. For the ELAC2, use the indications between the parentheses. ware0 PN & operational software PN specifi city compared to earlier stand- 03C 08 ASNA2397-6L .WASHER 016 (1) Do the procedure to get access to the SYSTEM REPORT/TEST F/CTL page combination0 compatibility with the ards of computers. (Ref. AMM TASK 31-32-00-860-006) . 03C 09 E0165D01A27 .CONNECTOR-RECEPTACLE 2CE1A, 2CE2A 002 0 ACTION RESULT 03C 10 3945129100 .ELAC-ELEVATOR AILERON COM- 2CE1, 2CE2 002 ( fi g . 2 ) 1.Push the line key adjacent to the EFCS 1(2) in- · The EFCS 1(2) menu page comes into view. 3 PUTER dication. ELAC B-DL HARDWARE HAS P/ The IPC raises awareness on FLS 2.Push the line key adjacent to the LRU IDENTI- · The LRU IDENTIFICATION page comes into N 3945129100. IT IS USED FOR FICATION indication. view. DATA-LOADABLE HARDWARE PART NUMBER WITHOUT ANY (2) Make sure that the P/N of the ELAC shown on the LRU IDENTIFICATION page is the same as the P/ INFORMATION REGARDING N on the media disk. THE OPERATIONAL SOFTWARE (a) If the P/N of the ELAC shown on the LRU IDENTIFICATION page is different from the P/N on the LOADED. Operational media disk, replace the ELAC. DATA-LOADABLE ELAC PN 3945129100 INTERCHANGEAB- software NOTE: If the two ELACs were not loaded with the same software, make sure that the configura- ILITY AND MIXABILITY CONDI- tion of the ELAC1/ELAC2 is a permitted configuration. TIONS identifi cation (LRU DEPEND ON THE OPERATIONAL 5. Close-up SOFTWARE LOADED. SEE 27-93-34-01A 001K FOR DET IDENTIFICATION) Subtask 27-93-00-860-063-A ComputerA. Put theremoval aircraft back &to itsinstallation initial configuration. is displayed in the cockpit, on the LRU Print Date: May 18, 2015 Page 1 of 2 is the ultimate safety (1) On the MCDU, push the line key adjacent to the RETURN indication until the CFDS menu page © AIRBUS S.A.S. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT. usually performedcomes into inview. line maintenance. IDENTIFICATION page, against the one Going further, Airbus aims at facilitating the visual distinction of the hardware barrier to prevent In practice, it may for example mean showed on the media disk is the only between the ones including the data loading function and the others. To this being under operational pressure way to detect any discrepancy whatever end, work is already ongoing in order to defi ne and develop a new label that inappropriate Print Date: May 18, 2015 Page 2 of 3 to© AIRBUS keep S.A.S. the ALL aircraft RIGHTS RESERVED. on schedule. CONFIDENTIAL itsAND origin. PROPRIETARY Indeed, DOCUMENT. as mentioned earlier, will be placed onto each DLU. This reinforced attention getter will aim at FLS and aircraft However, performing this check of the a quick look at the DLU hardware can improving the visual identifi cation of DLUs and thus, reminding the need to confi gurations. software reference between the one only tell part of the story. check the operational software PN.

For those who have already experienced losing one of their favourite functionalities on their computer, smartphone or tablet because a new version of operating system had been developed and not yet updated on it, it is an unpleasant experience. When it comes to a Flight Control or Auto Flight computer loaded with a wrong operational software version, it can be far worse since it can affect safety. No doubt it is worth the very limited time and effort of a LRU IDENTIFICATION! 060 Safety First #21 | January 2016

Issue 11 Issue 10 Issue 9

January 2011 August 2010 February 2010 ARTICLES PUBLISHED • What is Stall? How a Pilot Should • A380: Flutter Tests • A320 Family: Evolution of Ground IN PREVIOUS React in Front of a Stall Situation • Operational Landing Distances: Spoiler Logic • Minimum Control Speed Tests A New Standard for In-fl ight Landing • Incorrect Pitch Trim Setting at Take-Off ‘SAFETY FIRST’ ISSUES on A380 Distance Assessment • Technical Flight Familiarization • Radio Altimeter Erroneous Values • Go Around Handling • Oxygen Safety • Automatic NAV Engagement at Go • A320: Landing Gear Downlock Around • Situation Awareness and Decision Making

Issue 8 Issue 7 Issue 6

July 2009 February 2009 July 2008 Issue 20 Issue 19 Issue 18

July 2015 January 2015 July 2014 • The Runway Overrun Prevention • Airbus AP/FD TCAS Mode: A New • A320: Runway Overrun System Step Towards Safety Improvement • FCTL Check after EFCS Reset on Ground • The Take-Off Securing Function • Braking System Cross Connections • A320: Possible Consequence of VMO/ • Control your speed... during climb • Tidy cockpit for safe fl ight • Control your speed... at take-off • Computer Mixability: • Upset Recovery Training Aid, Revision 2 MMO Exceedance • Lateral runway excursions upon landing • Landing on contaminated runways • Safe operations with composite aircraft An Important Function • Fuel Pumps Left in OFF Position • A320: Prevention of Tailstrikes • Fuel monitoring on A320 Family aircraft • Understanding weight & balance • Learning from the evidence • Fuel Spills During Refueling Operations • A320: Avoiding Dual Bleed Loss • Low Fuel Situation Awareness • Hight-altitude manual fl ying • Wind shear: an invisible enemy to pilots? • A320 Family cargo Containers/ pallets • Rudder Pedal Jam movement • Why do Certain AMM Tasks Require • Parts Departing from Aircraft (PDA) Equipment Resets? • Slide/raft Improvement • Cabin Attendant Falling through the Issue 17 Issue 16 Issue 15 Avionics Bay Access Panel in Cockpit

January 2014 July 2013 January 2013 Issue 5 Issue 4 Issue 3

• Airbus Brake Testing • Performance Based Navigation: • The Golden Rules for Pilots moving December 2007 June 2007 December 2006 • Hard Landing, a Case Study for Crews RNP and RNP AR Approaches from PNF to PM and Maintenance Personnel • Atlantic Airways: Introduction • Airbus Crosswind Development and • Aircraft Protection during Washing and of RNP AR 0.1 Operations Certifi cation • New CFIT Event During Non Precision • Operations Engineering Bulletin • Dual Side Stick Inputs Painting • Flight Crews and De-Icing Personnel • The SMOKE/FUMES/AVNCS SMOKE Approach Reminder Function • Trimmable Horizontal Stabilizer Damage • Flight Data Analysis (FDA), a Predictive – Working together in Temporary Procedure • A320: Tail Strike at Take-Off? • Avoiding High Speed Rejected Take-Offs • Pitot Probes Obstruction on Ground Tool for Safety Management System Teamwork for safe Skies • Post-Maintenance Foreign Objects • Unreliable Speed Due to EGT Limit Exceedance • A340: Thrust Reverser Unlocked (SMS) • Low Speed Rejected Take-Off upon Damage (FOD) Prevention • Compliance to Operational Procedures • Do you Know your ATC/TCAS Panel? • Residual Cabin Pressure • Flying a Go-Around, Managing Energy Engine Failure • Corrosion: • The Future Air Navigation • Managing Hailstorms • Cabin Operations Briefi ng Notes • Late Changes before Departure A Potential Safety Issue System FANS B • Introducing the Maintenance Briefi ng Notes • Hypoxia: An Invisible Enemy • A320: Dual hydraulic Loss • Terrain Awareness and Warning Systems Issue 14 Issue 13 Issue 12 Operations Based on GPS Data

July 2012 January 2012 July 2011 Issue 2 Issue 1

• Thrust Reverser Selection means • A320 Family / A330 Prevention and • Airbus New Operational September 2005 January 2005 Full-Stop Handling of Dual Bleed Loss Landing Distances • Transient Loss of Communication due • The Fuel Penalty Factor • The Go Around Procedure to Jammed Push-To-Talk A320 and • The Airbus TCAS Alert Prevention • The Circling Approach • Tailpipe or Engine Fire • Go Arounds in Addis-Ababa due to VOR A330/A340 Families (TCAP) • VMU Tests on A380 • Managing Severe Turbulence Reception Problems • A380: Development of the Flight • A380: Development of the Flight • Automatic Landings • Airbus Pilot Transition (ATP) • The Importance of the Pre-fl ight Flight Controls - Part 2 Controls - Part 1 in Daily Operation • Runway Excursions at Take-Off Control Check • Preventing Fan Cowl Door Loss • Facing the Reality of everyday • A320: In-fl ight Thrust Reverser Deployment • Do not forget that you are not alone in Maintenance Operations • Airbus Flight Safety Manager Handbook Maintenance • Flight Operations Briefi ng Notes