QTR_04 14 A QUARTERLY PUBLICATION BROUGHT TO YOU BY THE BOEING EDGE

Information Solutions for a Competitive Advantage

Making Composite Repairs to the 787

How to Determine Hard and Overweight Landing Inspection Requirements

Avoiding Airplane Hazardous Energy Cover photo: 787 Wing Assembly AERO Contents

03 Information Solutions for a Competitive Advantage Boeing focuses on delivering intelligent information solutions by con­necting people, airplanes, and operations.

05 Making Composite Repairs to the 787 The benefits of composite materials 05 include quick repairs to certain kinds of damage­—often while a plane is in service.

15 How to Determine Hard and Overweight Landing Inspection Requirements A new inspection procedure reduces unnecessary inspections and maintenance 15 costs after hard or overweight landings. 21 Avoiding Airplane Hazardous Energy Boeing’s internal process improvements to control airplane hazardous energy in its factories will be made available in the aircraft maintenance manual.

21

01 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Issue 56 _Quarter 04 | 2014 AERO

Publisher Design Cover photography Editorial Board Chris Villiers Methodologie Jeff Corwin Don Andersen, Gary Bartz, Richard Breuhaus, David Carbaugh, Laura Chiarenza, Justin Hale, Darrell Hokuf, Al John, Doug Lane, Jill Langer, Duke McMillin, Editorial director Writer Printer Keith Otsuka, David Presuhn, Wade Price, Jerome Schmelzer, Corky Townsend Stephanie Miller Jeff Fraga ColorGraphics Technical Review Committee Editor-in-chief Distribution manager Web site design Gary Bartz, Richard Breuhaus, David Carbaugh, Laura Chiarenza, Justin Hale, Jim Lombardo Nanci Moultrie Methodologie Darrell Hokuf, Al John, David Landstrom, Doug Lane, Jill Langer, Duke McMillin, David Presuhn, Wade Price, Jerome Schmelzer, Corky Townsend, William Tsai

AERO Online www.boeing.com/boeingedge/aeromagazine

The Boeing Edge www.boeing.com/boeingedge

AERO magazine is published quarterly by Boeing Commercial Airplanes and is Information published in AERO magazine is intended to be accurate and authoritative. distributed at no cost to operators of Boeing commercial airplanes. AERO provides However, no material should be considered regulatory-approved unless specifically stated. operators with supplemental technical information to promote continuous safety Airline personnel are advised that their company’s policy may differ from or conflict with and efficiency in their daily fleet operations. information in this publication. Customer airlines may republish articles from AERO without permission if for distribution only within their own organizations. They thereby The Boeing Edge supports operators during the life of each Boeing commercial assume responsibility for the current accuracy of the republished material. All others airplane. Support includes stationing Field Service representatives in more than must obtain written permission from Boeing before reprinting any AERO article. 60 countries, furnishing spare parts and engineering support, training flight crews and maintenance personnel, and providing operations and maintenance publications. Print copies of AERO are not available by subscription, but the publication may be viewed on the Web at www.boeing.com/boeingedge/aeromagazine. Boeing continually communicates with operators through such vehicles as technical meetings, service letters, and service bulletins. This assists operators in addressing Please send address changes to [email protected]. Please send all other regulatory requirements and Air Transport Association specifications. communications to AERO Magazine, Boeing Commercial Airplanes, P.O. Box 3707, MC 21-72, Seattle, Washington, 98124‑2207, USA. Copyright © 2014 The Boeing Company E-mail: [email protected]

AERO is printed on Forest Stewardship Council® Certified paper.

02 AERO QUARTERLY QTR_04 | 14 Information Solutions for a Competitive Advantage

The Digital Aviation team within Commercial AerData Group B.V. makes it easier for Aviation Services delivers mission-critical airlines and leasing companies to manage information solutions that give our cus­ complex data records by providing tomers a competitive advan­tage by helping integrated software solutions for lease them solve operational problems in real management, engine fleet planning, and time and operate more efficiently. We help records management, as well as technical them make better decisions as they relate services for airplane and engine operators, to fuel consumption, crew planning, Aircraft lessors, and maintenance, repair, and Health Management, and navigation and overhaul companies. flight planning. Our focus is in delivering We have a number of the most intelligent information solutions by con­ advanced planning and day-of-operations necting people, airplanes, and operations. solutions in the industry today, supported Earlier this year, we acquired two companies by a global team rich in experience, that brought us additional capabilities in knowledge, and passion for our customers this regard. and the aviation industry. Our success ETS Aviation offers the tools necessary comes from listening carefully and collab­ to accurately monitor fuel consumption, orating closely with our customers to identify fuel savings opportunities, and understand needs, and then implementing track and report carbon emissions. With solutions that deliver true value for the MARK VAN TINE fuel costs accounting for as much as long term. We look forward to working Vice President 40 percent of airline operating costs, with you!A Digital Aviation reducing fuel consumption enables Boeing Commercial Airplanes airlines to be more successful while also reducing emissions.

03 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Boeing has developed tools, information, and training to help airlines repair the 787’s composite structure and surfaces.

04 AERO QUARTERLY QTR_04 | 14 Making Composite Repairs to the 787

The 787 Dreamliner offers a number of operational benefits due to the airframe comprising approximately half (by weight) carbon fiber reinforced plastic and other composites. As airlines add the 787 to their fleets, they are increasingly interested in repair methods for the airplane’s composite structure. Boeing offers information to enable airlines to make effective repairs to many different types of damage — often without taking the airplane out of service.

By Arne Lewis, Associate Technical Fellow, Commercial Aviation Services, 787 Service Engineering

The 787’s composite structure has airframe THE EVOLUTION OF COMPOSITES IN form or composition on a macro scale. The maintenance costs that are 30 percent COMMERCIAL AVIATION constituents retain their identities: While lower than any comparable airplane. This is they act in concert, they do not dissolve largely due to its absence of corrosion and Aluminum structures have been a mainstay or merge completely into one another. fatigue, the two primary drivers for repair in commercial airplane design for many Composites also offer strength-to- and maintenance of the airplane structure. years. While the evolution of aluminum weight ratios that enable lighter weight The 787 also weighs, on average, less than designs has improved the strength- structures that allow the airplane design to more conventional aluminum designs, to-weight ratio, the industry has been feature items such as larger windows and resulting in greater fuel efficiency. The seeking double-digit performance lower altitude pressures in the cabin. In combination of these two factors made the improvements in fuel efficiency for new addition, a composite airplane structure choice for a composite airframe very airplanes. Composites, combined with has inherent resistance to fatigue damage appealing to designers and airlines. system improvements, have helped provide and corrosion. This article will help the reader the path to such improvements. Composites are not new to commercial understand why composites were chosen A composite is a combination of two or aviation. In fact, composites have been for the 787 and what Boeing is doing to more materials (reinforcing elements, fillers, used in airframe structures since the help the repair community transition to and composite matrix binder) differing in 1950s, and their use has been increasing repairing composites.

05 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 1: The aftbody sections of the 787 Dreamliner are created using an advanced carbon fiber placement technology As pictured here, an automated fiber placement AFP( ) machine in Boeing’s South Carolina facility lays carbon fiber tape using precise patterns and layers to maximize the strength of the barrel.

steadily over the last 45 years. Composite structure for function, load carrying strengthened and designed to enable structures on commercial airplanes (see capability, and durability. This evaluation repairs if damaged. fig. 1) can be all fiberglass layers, all carbon resulted in composite materials being used Due to its use of toughened carbon layers, a mixture of the two (often referred extensively on the 787 airframe, making materials, solid laminate composite to as hybrid parts), or cured with these materials dominant in areas that are structure is inherently very durable. Tests honeycomb core (see fig. 2). Over time, traditionally aluminum (see fig. 3). have shown the 787 fuselage can resist tougher composite materials and Many studies, tests, and demonstrations damage that would easily occur in an enhanced, robust designs have been were performed to validate the strength aluminum fuselage. developed and are being used for primary and impact resistance of the composite structure on both the 777 and the 787. material, particularly in comparison to MAINTAINABILITY: A KEY 787 DESIGN aluminum structures. Additionally, in REQUIREMENT conjunction with airline partners, many USE OF COMPOSITES ON THE damage scenarios were reviewed and the BOEING DREAMLINER The ability of airlines to maintain the 787 time and effort required to repair each type was a key consideration during its of damage were evaluated. In developing the 787, Boeing determined development. The airplane’s structure was The damage scenarios and impact the most effective use of composites by designed for robustness in an in-service testing provided necessary information to evaluating every element of the airplane’s environment. Maintenance and repair assure areas prone to damage were 06 AERO QUARTERLY QTR_04 | 14 Figure 2: Types of composites Composites on commercial airplanes include fiberglass solid laminates (top), carbon solid laminates (center), or cured with a honeycomb core (bottom).

07 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 3: Composites on the 787 Composites comprise more than 50 percent of the 787 airframe.

Materials ■ Carbon laminate ■ Carbon sandwich ■ Other composites ■ Aluminum ■ Titanium ■ Titanium/Steel/Aluminum

787

Materials by weight ■ Composite ■ Aluminum ■ Titanium ■ Steel ■ Miscellaneous

08 AERO QUARTERLY QTR_04 | 14 Figure 4: 787 maintenance cost reductions In addition to longer intervals between scheduled maintenance checks, the 787 reduces labor hours by approximately 20 percent on a per-check basis. Total scheduled labor hours are reduced by approximately 60 percent over the life of the airplane. These reductions in required scheduled maintenance are a significant contributor to the 787’s overall 30 percent airframe and systems maintenance cost reduction target.

C-Check years D-Check years A330-300 A330-200 787-9 787-8 Annual Amortized Airframe Maintenance Cost

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Years in Service

considerations were inherent in the design. this type of force applied to an aluminum 787 SRM chapter 51 to explain repair Boeing developed inspection equipment fuselage would have caused damage processes and procedures for: and techniques to support unplanned that would have taken the airplane out ■■ Pre-impregnated repairs (both original maintenance, such as airplane-on-ground of service for several days. cure temperature and reduced tem­ events. perature cure) use material that has The 787 program had a maintenance NEW REPAIR INSTRUCTIONS IN THE been frozen, thawed, and then cured cost reduction target of approximately 787 STRUCTURAL REPAIR MANUAL with heat. 30 percent (see fig. 4). More than 100 design (SRM) ■■ Wet layup repairs use dry fabric that is requirements and objectives were related impregnated with resin. to repair and maintenance. Successful repairs to composite structure ■■ Bolted repairs for common architecture Operators’ in-service experience has require the repair technician to strictly follow elements, including the skin-stringer, demonstrated the robustness of the 787’s detailed and accurate repair instructions. frame, and shear tie. This repair uses composite structure. For example, one For quality enhancement, the 787 SRM sheet metal (aluminum, titanium, or operator reported that hangar scaffolding builds upon the established composite steel/corrosion-resistant stainless steel) came in contact with one of its 787s. The repair techniques and materials that Boeing bolted onto the structure. The repair discrepant area was inspected fully and successfully developed for the 777. Since can be flush with the airplane skin or, in found not to have any type of delaminations the 787 has extensive composite structure, or damage. The airline also reported that more than 20 new sections were added to 09 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 5: New inspection techniques Maintenance personnel can first use a ramp damage checker (left and center) and, if necessary, the wheel probe (right) to quickly assess the condition of laminate and sandwich structures on the 787.

some cases, might protrude into the vacuum bag debulk (DVD) system, a newer and/or on the interior side of the fuselage. airstream. process that is implemented for several 787 Because of this different manifestation of ■■ Quick composite repairs (see “Special repairs. The 787 SRM describes how damage, the aircraft maintenance manual kit enables airlines to make quick technicians can construct a DVD box from (AMM) addresses specific conditions and composite repairs” on page 12). simple lumber materials. inspections that need to be accomplished. The development of the 787 also The new sections in the SRM address included the creation of a simplified clean environments for bonding repairs on ASSESSING DAMAGE ON THE 787 inspection device to aid maintenance the airplane, better ply compaction personnel in assessing the extent of methods to reduce porosity, drying solid Damage to composite structure can damage. The inspection device, called the laminate, and performing heat surveys to manifest itself differently than in aluminum ramp damage checker, was developed assure proper heat distribution during the structures. Because aluminum usually specifically for the ramp technician. For repair cure. Most of the repairs in the 787 dents or tears, damage is typically visible. additional damage characterization and SRM use tools and equipment that have In contrast, composites will show rub more in-depth inspections, a wheel probe been used to repair legacy airplane marks or a small dent. If there is enough was developed to speed and simplify the composite components and have been energy transferred, a delamination of plies assessment of laminate and sandwich available on the market for many years. may occur. When the delamination is structures (see fig. 5). Heat damage can be One exception is the use of a double critical, it will be visible on the exterior side detected using instrumented inspection 10 AERO QUARTERLY QTR_04 | 14 Figure 6: Repair method considerations Airlines have the option of bolted or bonded repairs. Each approach has its advantages.

BOLTED REPAIR BONDED REPAIR

Benefits ■■ Faster processing time. ■■ No protruding parts. ■■ No risk of heat damage. ■■ Lightweight. ■■ Repair material not sensitive. ■■ Category A (permanent repair).

Other Considerations ■■ Heavier. ■■ Slower processing time. ■■ Hole drilling must be done with ■■ Risk of heat damage and porosity. care and caution. ■■ Material is time, temperature, and ■■ Repairs may be Category B moisture sensitive. (require inspections).

methods as outlined in the nondestructive The repair technologies Boeing has method that restores ultimate load carrying inspection manual. developed for the 787 build upon the capabilities and meets the operational Please note that any significant impact success of 777 composite repairs. needs of the airline. The airline needs to or damage needs to be inspected per the Numerous repair tests were made based factor in: instructions in the 787 SRM and/or the 787 on repairs described in the SRM to validate ■■ Which repair method will get the airplane AMM, chapter 5. repair capabilities. Repair tests included back into revenue service the soonest. static and fatigue (including accidental ■■ Repair environment (weather condition, damage and environment effects), tension, ADVANCED REPAIR TECHNOLOGIES hangar availability). compression, and combined loads. ■■ Repair material availability. Boeing’s research and in-service Boeing has extensive experience ■■ How much weight will be added to the experience have demonstrated repairs for supporting composite structures in service. airplane. all areas of composite structures using In addition, Boeing participates actively in ■■ How much aerodynamic drag will be bonded repairs, bolted repairs, or a hybrid forums such as the SAE-sponsored added to the airplane. comprising bonding with a bolted Commercial Aircraft Composite Repair substructure (see fig. 6). There are various When damage is determined to be Committee to gain and share knowledge factors an airline needs to consider when minor, quick repairs to the composite about composite repairs. choosing which type of repair to make. The surface can be accomplished in about an SRM only allows you to choose the repair hour using a prepackaged time-limited 11 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Special kit enables airlines to make quick composite repairs

Because ramp rash and other minor minor damage to be repaired at the gate, The QCR kit includes sanding disks, mishaps are a fact of life for a commercial quickly and with no electricity. gloves, lint-free wipes, vacuum bag film, airplane, Boeing has developed a quick To create the kit, Boeing’s research structural patches, anti-caul foil patches, way to repair composite materials. Pre­ team narrowed 150 candidate adhesives heat pack, and adhesives. viously, the most common way to fix down to 10, evaluating them in laboratory­ The areas of the airplane where Quick composite skin damage involved moving tests during a four-year period. The Composite Repairs can be used and the airplane to a maintenance hangar and adhesives were subjected to extreme hot application­ instructions are provided using sophisticated cure controllers and and cold thermal conditions and tested for in the 787-8 and 787-9 SRMs. QCR heater mats to cure epoxy resins and their shelf life, curing temperatures, and kits can be obtained through Boeing adhesives in place. In contrast, the 787 bond strength, among other parameters. Material Services. Quick Composite Repair (QCR) kit allows

composite repair kit. (See “Special kit Lightning strikes. Studies have shown that and service can resume immediately until enables airlines to make quick composite the airplane surface shapes are the deter­ the airplane can be put into maintenance at repairs” above.) mining factor for lightning strike attachment. a more convenient time. If the damage is Regardless of which method is selected, (See AERO, second-quarter 2012.) While larger than allowable damage limits, most all 787 SRM repairs are structurally accept­ lightning strike damage can occur to damage can be repaired using wet layup able when applied as directed in the SRM. composite structures, the damage is often methods that have been used in the minimal and repairable with a time-limited aviation industry for many years. repair. The damage must first be inspected SPECIAL DAMAGE CASES Large area damage. This type of damage for size and depth. Once the size and is generally considered to be an area of depth are known, the airline will need to Because of the uniqueness of the 787 approximately 3 feet by 3 feet (1 meter by review the SRM for allowable damage limits composite structure, many repair questions 1 meter) or larger. Damage of that size and and decide on the proper course of action. from operators have centered on two larger is repaired using a pre-cured panel There have been many instances where the specific types of damage: lightning strikes bolted in place with splicing straps and lightning damage can be sealed with resin and large area damage. doublers. This method has been success‑­ or aluminum foil tape as a temporary repair fully performed in-service on 787 fuselage

12 AERO QUARTERLY QTR_04 | 14 It is important that airlines receiving 787s review their capabilities, knowledge, repair processes, repair materials, and training to ensure they are prepared for repair. Because of the increased use of composites on the 787, Boeing has developed a suite of composite structure repair classes specifically for the 787.

structures. In cases where the fuselage developed a suite of composite structure SUMMARY was damaged through the thickness, the repair classes specifically for the 787. These Boeing airplane-on-ground team was classes include: Boeing has developed unique tools, dispatched and successfully performed information, and training to help airlines ■■ Line and Base Mechanics course. permanent bonded and bolted repairs. make repairs to the 787’s composite Standard Air Transport Association (ATA) structure and surfaces. These tools enable 104 level 3 course. airlines to make effective repairs to many BOEING STRUCTURES REPAIR ■■ TRAINING Technicians course. Designed for different types of damage, in many cases mechanics who perform composite without leaving the gate.A repairs on a daily basis. It is important that airlines receiving 787s review their capabilities, knowledge, repair ■■ Engineers course. For engineers who processes, repair materials, and training to design the repairs for the technicians. ensure they are prepared for repair. ■■ Inspectors course. Designed for line, Because of the increased use of base, and back shop inspections. composites on the 787, Boeing has

13 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Revised inspection procedures for reported hard and overweight land­ ings help mainte­nance determine the appropriate level of inspection. How to Determine Hard and Overweight Landing Inspection Requirements

Boeing has developed a new inspection procedure that maintenance personnel can use immediately after the flight crew reports a hard or overweight landing to determine the appropriate level of inspection. This new procedure will reduce maintenance costs for airlines by reducing unnecessary inspections.

By Michael Harrison, Maintenance Engineer, Structures and Mechanical Systems; Jack Hagelin, Loads and Dynamics Technical Fellow; and Gary Bartz, Chief Design Engineer, DC-9/MD-80/MD-90/717

Boeing airplanes are designed to withstand Procedures contained in aircraft main­ reduced if the data shows that these touchdown rates well above typical touch­ tenance manuals (AMMs) for hard landing parameters are within prescribed limits. down rates seen during daily operations. inspections include a single vertical load AMMs prescribe a special maintenance Even a perceived hard landing is usually factor (VLF) value, in Gs, to assist operators inspection whenever a hard or overweight well below these design criteria. Boeing in determining whether a hard landing landing has been reported by the flight policy is that a pilot report is the only factor was experienced. crew. A review of both hard and overweight that consistently identifies a hard landing. Boeing is revising the AMM hard and landing inspection procedures indicated If the pilot believes that a hard landing overweight landing inspection procedures that the airplane items recommended to be may have occurred, it should be reported. for all commercial models to provide an checked were similar. As a result, Boeing A maintenance inspection will determine if option for operators to utilize flight recorded has combined both inspections into one further maintenance action is needed. data to determine the level of inspection procedure for some models, and intends required based on landing weight, VLF, and to expand this to most other models. roll angle. The level of inspection may be

15 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 1: AMM hard/overweight landing inspection label The new AMM hard and overweight landing inspection procedures split the Phase I inspection into two parts using the nomenclature below.

7-Series Inspections MD Models and 717

Phase IA A-1 Check

Phase IB A-2 Check

Phase II B Check

The revised procedures specify limits In some prior AMM procedures, a inspection of less than an hour without for VLF and roll angle for landing weights at complete Phase I inspection has been removing the airplane from flight operations and above the maximum certified landing required whenever a hard or overweight if the relevant data (i.e., roll angle, peak weight. In addition, the Phase I inspection landing is reported by the flight crew, even VLF, and landing weight) show the landing is split into two parts: Phase IA and Phase if the flight recorded data shows that the was below prescribed limits. This new IB (see fig. 1). This article provides back­ landing was within normal landing limits. procedure will reduce service disruptions ground about the new procedures and how The flight crew report resulted in a Phase I and maintenance costs while maintaining operators can implement them. inspection that involved pulling the airplane the same level of airplane integrity. out of service and into a hangar for several hours for inspections. Experience has CHANGING THE HARD AND INSPECTION PROCEDURE FOR OVERWEIGHT LANDING INSPECTION shown that most landings that are called LANDINGS REPORTED AS HARD PROCEDURE “hard” by the flight crew are in fact within the structural design limits. Currently the inspection procedure on A coordinated effort within Boeing, com­ The revised procedure allows the some models is divided into Phase I and bined with feedback from several operators, operator to waive some of the Phase I Phase II inspections. The new standardized has resulted in a change to the hard and inspections if the airplane’s flight recorded procedure splits the Phase I inspection into overweight landing inspection procedures data of VLF and roll angle from the Flight two parts: IA and IB (see the left side of for all Boeing airplane models. This new Data Recorder (FDR), or other equivalent fig. 2). Phase IA is a visual inspection, while standardized procedure is found in AMM recording device, indicate that the landing Phase IB may include inspections requiring Section 05-51. was within specified limits. The new removal of parts. Phase IA is required if the inspection procedure allows a shortened

16 AERO QUARTERLY QTR_04 | 14 Figure 2: Revised hard/overweight landing inspection flow chart Previous hard landing procedures dictated a lengthy inspection whenever the flight crew reported a hard landing. The revised procedures use flight recorded data to help maintenance crews determine the level of inspection required.

(Airplane Model) Aircraft Maintenance Manual Landing Inspection Flow Chart

Pilot reports hard or Pilot reports overweight-only overweight-hard landing landing (not a hard landing)

Download/review Download/review No No flight-recorded data flight-recorded data

Yes Yes

Landing vertical load Landing vertical load No No factor (Gs) is ≤ VLF factor (Gs) is ≤ VLF

Yes Yes

Do A-1 Check Do A-1 and A-2 Check Do A-1 Check

No Damage found Damage found No Damage found No

Yes Yes Yes

Do A-2 and applicable Do applicable Do A-2 and B Check B Check applicable B Check

Complete all repairs Complete all repairs

Return Airplane to Service

17 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 3: Revised landing vertical load factor (VLF) inspection limits A Phase IB inspection can be waived if the touchdown peak VLF is less than the prescribed limit, which is now a function of roll angle.

777 CG LOAD FACTOR AMM THRESHOLD 2.5 ≤MLW + 4,000 lb, 2.4 16+ samples/sec 2.3 ≤MLW + 4,000 lb, 2.2 8+ samples/sec >MLW + 4,000 lb, 2.1 16+ samples/sec 2.0 >MLW + 4,000 lb, 1.9 8+ samples/sec 1.8 1.7 1.6 1.5 Vertical Load Factor (Gs) Vertical 1.4 CG 1.3 1.2 1.1 1.0 0 1 2 3 4 5 6

Roll Angle (degree)

flight crew reports a hard landing. PhaseIB INSPECTION PROCEDURE FOR design landing weight due to unanticipated can be waived if: OVERWEIGHT LANDINGS winds and other factors.

■■ No damage was found in the Phase IA Overweight landing inspections can now inspection. NEW HARD/OVERWEIGHT LANDING also use flight recorded landing data to ■■ The touchdown peak VLF was less than INSPECTION LIMITS determine the level of inspection required. the prescribed limit, which is now a The Phase IA inspection, at a minimum, will function of roll angle and landing weight As part of the new hard/overweight landing be required for overweight landings that are (see fig. 3). inspection procedure, the landing VLF limits also reported as hard by the flight crew. For ■■ The roll angle was less than 6 degrees. in the AMM are revised as follows (see fig. 3 overweight landings that are not reported ■■ It was not a bounced landing. as an example based on the 777): as hard, the inspection is waived, provided ■■ It was not a hard nose-gear landing. the flight recorded data ofVLF and roll ■■ The range of VLF limits is expanded (The flight crew must specify whether angle from the FDR or other equivalent from 0 degrees to 6 degrees of roll the hard landing was on the main or recording device are below the specified angle. nose gear because the VLF limit is only limits (see the right side of fig. 2). In ■■ A VLF limit line for landing weights above applicable to main gear landings.) addition, the definition of an overweight the maximum landing weight (MLW), The Phase II inspection remains landing (for the purpose of the structural including a small weight tolerance, is unchanged in this new procedure. (For inspection) is changed to any landing that added, enabling this chart to be used for 767 and 777 models, some main gear fuse is above the maximum certified design overweight landings. pin inspections have been moved from landing weight plus a small weight ■■ The VLF limits are based on at least eight Phase IB to Phase II to further reduce tolerance. This weight tolerance represents samples per second recording rate. inspection time.) about 1 percent of the design landing ■■ The roll angle values are based on weight and is added in recognition of the at least four samples per second potential for landing slightly above the recording rate.

18 AERO QUARTERLY QTR_04 | 14 Flight recorded data Using these new and optional inspection unit, Honeywell Hand Held Download Unit, Data from airplanes having these procedures (flight recorded data to or other similar units. easier and quicker recording systems determine the level of inspection) depends Airplanes with more modern digital with access to flight recorder data can on how quickly the relevant parameters subsystems are equipped with digital be considered to be equivalent data (landing weight, vertical load factor [VLF], flight data recorders (DFDRs) and digital from data downloaded from the DFDR/ and roll angle) can be obtained after a flight data acquisition units DFDAU( s). FDR—provided the operator develops reported event. Thus, download time for DFDAUs are frequently, but not always, a means to validate equivalency. The retrieving the relevant parameters from combined with an Aircraft Condition means of determining this equivalency flight recorded data for analyzing hard or Monitoring System (ACMS) with easier is dependent on meeting certain criteria, overweight landings will vary depending on and quicker access to flight recorder such as sampling rate, data validation, the vintage of the airplane model and the data needed for flight performance and and configuration control if it is airline or type of recording equipment installed. For engine trending analysis, as well as hard/ non-OEM modifiable software, to example, airplanes produced earlier than overweight landing analysis. ACMS determine the level of inspection required. the mid-1980s have flight data recorders application software processes selected One means, but not the only means, to do (FDRs) and analog flight data acquisition parameter data through a dedicated this would be to download data from a units flight recording systems that would processor, separate from the mandatory landing and compare the applicable FDR record VLF and roll angle parameters but FDR processor. The ACMS data can parameters (known good data) and the with inadequate sampling intervals for then be recorded using an optical quick corresponding parameters from the accurate landing analysis. However, data access recorder or transmitted to a equivalent recording device (i.e., validation from any vintage airplane model can be ground station using an Aircraft Commu­ of data and sampling rate for a common downloaded by bringing the FDR into a lab nications And Reporting System (ACARS) reference time period), along with the and using FDR data reduction equipment, without the need to remove and download airline procedures that control the user- such as an Avionica ruggedized service the DFDR. modifiable software for these parameters.

787 HARD/OVERWEIGHT LANDING The 787 inspection procedure is divided SUMMARY INSPECTION LIMITS into Phase I and Phase II inspections. However, the Phase I inspection is not split Revised AMM inspection procedures for The 787 AMM inspection procedure for into two parts as with other models. The reported hard and overweight landings use hard/overweight landings currently makes procedure contains tables of parameter flight recorded data ofVLF and roll angle use of a hard landing maintenance page values that maintenance personnel can from the FDR or other equivalent recording that is available immediately after compare to the actual landing values devices to help maintenance personnel touchdown and is therefore not being obtained from the airplane. determine the appropriate level of airplane revised. However, the advanced systems The values of the relevant parameters inspection. This revision will result in and recording equipment on the 787 can be found by accessing the Air maintenance cost savings to operators by enables the AMM inspection procedure to Transport Association (ATA) 51 Landing way of fewer inspections and shorter down include additional parameters beyond the Conditions maintenance page from the 787 times when inspections are needed. These peak VLF. The airplane sink rate, pitch flight deck using the multifunction display or improved AMM inspection procedures have attitude, crab angle, roll angle, roll rate, and a maintenance laptop. After selecting the already been released for some models pitch rate are also used to determine if an appropriate AMM table based on landing and are being planned for most models of inspection is required following a hard or weight, maintenance personnel can then Boeing airplanes. overweight landing. If all parameters fall compare the values from the ATA 51 For more information, contact within the limits specified in theAMM , no Landing Conditions maintenance page to [email protected] inspections are required. While more the values in the AMM table. If all of the advanced, this approach of using airplane values are within the limits specified in the recorded data is similar to what is/will be AMM table, no inspection is required. If any used on other models. value is outside the limits, the full Phase I The capability to identify a hard nose- inspection is necessary. gear landing is also available on the 787 by Starting in 2015, some models of the using the body pitch rate just prior to nose- 777 will also incorporate a hard landing gear touchdown. This new capability is display page similar to the 787. available only on the 787.

19 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Boeing procedures to protect personnel from hazardous energy sources will be available in aircraft maintenance manuals.

20 AERO QUARTERLY QTR_04 | 14 Avoiding Airplane Hazardous Energy

Exposure to energized airplane systems can result in serious injury to maintenance technicians if proper controls are not followed. Hazardous energy controls are required when technicians could be exposed to unexpected energization, startup, or release of hazardous energy during service or maintenance activities. Boeing has made internal process improvements to control airplane hazardous energy within Boeing factories and on Boeing flight lines and is making these improvements available to the aviation industry through updates to the aircraft maintenance manual (AMM).

By Bill Tsai, Associate Technical Fellow, Maintenance Engineering

Airplane hazardous energy can present controls are computer-controlled and can ■■ Electrical, such as primary external safety risks for maintenance technicians move unexpectedly in response to fault power at 115 volts (V) alternating current when working on airplanes. This is true detection. (AC) buses, auxiliary-power-unit (APU) both when an individual technician is This article describes some of the key generator power at 115 VAC buses, and performing service and maintenance, and sources of hazardous energy and how integrated-drive generator power at 115 also when multiple teams are working airlines can minimize the risk to technicians VAC buses. independent of each other on the airplane. working around them. ■■ Thermal, including pitot probe, angle-of- In some cases, one team’s work may attack sensor, wing anti-ice, window interfere with that of another team and POTENTIAL SOURCES OF HAZARDOUS heat, heated drain mast, nitrogen- introduce an unsafe condition. For ENERGY generating system exhaust, and cabin example, one team may finish its job early air compressor system. and reenergize the airplane system, Boeing has identified a number of potential endangering another team that is still ■■ Pneumatic. sources of hazardous energy relating to working on the airplane. Airplane hazardous airplane production, most of which also ■■ Hydraulic, such as the airplane’s energy also can be a problem when apply to maintenance operations, including pressurized hydraulics. technicians are unfamiliar with the high level the following: of automation in an airplane system. For ■■ Mechanical, including flight-control example, on fly-by-wire airplanes, the flight surfaces, jackscrews, torque tubes, 21 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 1: Changes to AMM task titles AMM task titles are being changed to better identify hazardous energy AMM tasks.

Existing AMM Task Title New AMM Task Title

777 777 AIRCRAFT MAINTENANCE MANUAL AIRCRAFT MAINTENANCE MANUAL TASK 24-22-805 TASK 24-22-805 2. Supply Electrical Power 2. Electrical Power Activation A. Location Zones A. Location Zones Zone Area Zone Area 211 Flight Compartment, Left 211 Flight Compartment, Left B. Procedure B. Procedure SUBTASK 24-22-00-860-800 SUBTASK 24-22-00-860-800 (1) Do one of these tasks to supply electrical power to the plane: (1) Do one of these tasks to supply electrical power to the plane: (a) Do this task: Supply Primary External Power, TASK 24-22-00-860-801 (a) Do this task: Activate Primary External Power, TASK 24-22-00-860-801 (b) Do this task: Supply Secondary External Power, TASK 24-22-00-860-802 (b) Do this task: Activate Secondary External Power, TASK 24-22-00-860-802 (c) Do this task: Supply APU Generator Power, TASK 24-22-00-860-803 (c) Do this task: Activate APU Generator Power, TASK 24-22-00-860-803 (d) Do this task: Supply IDG Power, TASK 24-22-00-860-804 (d) Do this task: Activate IDG Power, TASK 24-22-00-860-804 END OF TASK END OF TASK TASK 24-22-806 TASK 24-22-806 3. Remove Electrical Power 3. Electrical Power Deactivation A. Location Zones A. Location Zones Zone Area Zone Area 211 Flight Compartment, Left 211 Flight Compartment, Left B. Procedure B. Procedure SUBTASK 24-22-00-860-800 SUBTASK 24-22-00-860-800 (1) Do one of these tasks to supply electrical power to the plane: (1) Do one of these tasks to supply electrical power to the plane: (a) Do this task: Remove Primary External Power, TASK 24-22-00-860-807 (a) Do this task: Deactivate Primary External Power, TASK 24-22-00-860-807 (b) Do this task: Remove Secondary External Power, TASK 24-22-00-860-808 (b) Do this task: Deactivate Secondary External Power, TASK 24-22-00-860-808 (c) Do this task: Remove APU Generator Power, TASK 24-22-00-860-809 (c) Do this task: Deactivate APU Generator Power, TASK 24-22-00-860-809 (d) Do this task: Remove IDG Power, TASK 24-22-00-860-810 (d) Do this task: Deactivate IDG Power, TASK 24-22-00-860-810

END OF TASK END OF TASK

push rods, linkages, control cables, released by opening a relief valve or ■■ Latched faults. On fly-by-wire airplanes, powered doors, escape slides, powered cycling the system. Maintenance disconnecting electrical connectors to a seats, landing gear, thrust reversers, fan personnel must be aware of the monitored component may generate cowls, fan blades, springs, gears, and potential for residual pressure to remain latched faults, requiring numerous hours ram air turbines. in the airplane system and follow the of work to clear the latched faults. steps in the maintenance procedure to Maintenance personnel must dissipate it prior to starting work. understand these latched faults must be HAZARDOUS ENERGY AWARENESS cleared prior to reenergizing in order to ■■ Backup systems. Some airplane prevent unexpected flight movement of In general, technicians must be aware of systems have automated backup flight controls. Maintenance personnel factors such as residual pressure systems, and in many cases, these should be mindful of the possibility of (sometimes referred to as “stored energy”), systems must be disabled in order to excessive fault generation when backup systems, latched faults, and properly address sources of hazardous removing an electrical connector. unexpected movement when working on energy. Maintenance personnel should airplane systems containing hazardous be aware of the way systems are energy. On fly-by-wire airplanes, a integrated and that automated battery IMPLEMENTING HAZARDOUS ENERGY maintenance action may generate an backup systems can reenergize airplane CONTROL PROCEDURES IN THE AMM unintended consequence on the airplane. systems. Situations involving hazardous energy Boeing is enhancing the AMM to better ■■ Unexpected movement. Airlines should include: align with the hazardous energy control ensure that maintenance personnel are procedures (HECP) implemented as part of ■■ Residual pressure. In the deactivation warned of the potential for unexpected the safety program implemented in the procedures for hydraulic, pneumatic, or movement of airplane components (e.g., company’s factory. pressurized airplane systems, the flight control surfaces and hydraulic Boeing periodically reviews the HECPs residual pressure must be dissipated actuators) and cleared from the area created for use by Boeing factory personnel and the zero energy state must be prior to reenergizing. and on the flight lines to determine whether verified. Residual pressure is often

22 AERO QUARTERLY QTR_04 | 14 Figure 2: The lockout, tagout, and tryout (LOTO) system The lockout, tagout, and tryout system is designed to clearly communicate about potential energy hazards to maintenance personnel. Lockout (left) involves placing a lockout device on the airplane system. Tagout (center) places a warning tag on the airplane system. Tryout (right) is verification that the airplane system is in a zero-energy state.

Lockout Tagout Tryout

AIR SUPPLY L R HIGH PRESS S/O VALVE OPEN OPEN WARNING RESS REG VALVE OPEN OPEN PRESS REG S/0 VALVE OPEN OPEN FAN AIR VALVE ANGLE 0 0 Do Not Operate ENG HI FAN SPEED 0 0 ENG HIGH STAGE PRESS 0 0 INTERIM DUCT PRESS 2 0 0 Or Apply Power INTERIM DUCT PRESS 2 0 0 STRUT OVERHEAT NORMAL NORMAL ENG FIRE HANDLE NORMAL NORMAL MANIFOLD DUCT PRESS 0 0 PRECOOLER OUT TEMP 0 0 LEFT ISO VALVE OPEN RIGHT ISO VALVE OPEN CENTER ISO VALVE OPEN APU ISO VALVE OPEN

ALTITUDE FL 0 FLIGHT CRUISE CRUISE SAT 0

DATE 07 OCT 14 GMT 20:20:30

they can be applied with AMM procedures For existing hazardous energy AMM lockout and tagout draws upon U.S. Occu­ to better address hazardous energy. tasks, the AMM task title is changing to pational Safety and Health Administration Applicable hazardous energy AMM tasks include the terms “Deactivation” or (OSHA) regulations (Title 29 of the Code of are revised by integrating relevant content “Activation” (see fig. 1). Additionally, all Federal Regulations [CFR], Part 1910.147). from the HECPs. To retain the effectiveness airplane systems will be reviewed to Lockout is the placement of a lockout of current air-carrier maintenance determine whether new standalone device on the energy control device(s) of an procedures, only AMM tasks directly used “Deactivation” or “Activation” procedures airplane system to ensure that the airplane to control hazardous energy are updated. need to be added to the AMM. system cannot be operated until after the The updates to hazardous energy AMM lockout device has been removed. procedures are scheduled to begin in COMMUNICATING TO MAINTENANCE late 2014. PERSONNEL ABOUT POTENTIAL Tagout is the placement of a warning tag HAZARDS on the energy control device(s) of an airplane system to indicate that the airplane IDENTIFYING HAZARDOUS ENERGY PROCEDURES IN THE AMM Boeing recommends that airlines system must not be operated until after the implement a system in their maintenance warning tag is removed. procedures that clearly communicates to To help technicians distinguish the Tryout is verification that an airplane system maintenance personnel the potential risks hazardous energy AMM procedures from is in a zero-energy state and that residual associated with hazardous energy and the other types of maintenance procedures energy has been released. Tryout requires importance of compliance with AMM (e.g., servicing, component removal, that lockout devices and warning tags procedures. One such system is lockout, inspection, and test procedures), Boeing is cannot be violated to perform the tryout tagout, and tryout (LOTO) (see fig. 2), which enhancing the AMM to clearly identify AMM method. Tryout confirms that the airplane establishes a safe level of protection before tasks directly related to hazardous energy. system is in a safe condition prior to the the technician performs maintenance on the airplane. The safety approach for

23 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 3: Clarifying tryout requirements in the AMM The AMM updates identify tryout steps to hazardous energy AMM tasks for confirmation of zero energy state prior to performing maintenance.

Tryout heading Note explaining the purpose (1) Hydraulic System-Tryout of the tryout Note: This tryout is to make sure the hydraulic system is in a zero energy state. Tryout steps (a) Make sure that the hydraulic Systems 1, 2, 3, and 4 are all below 100 psig on EICAS. (b) Make sure that the FLT CONTROL SHUTOFF TAIL and FLT CONTROL HYD SHUTOFF WING valves are in the closed position on EICAS.

technician performing maintenance on the LOTO IN THE AMM that airplane system. Further, for oper­ airplane system. Tryout methods include: ational testing, functional testing, and The safety principles of LOTO are currently system testing, the airplane system must ■■ Operating the airplane system to confirm employed in the AMM. The tryout require­ be energized in order to perform the that the airplane is in a safe state. ment in a hazardous energy AMM procedure testing. In some cases, this testing will ■■ Using the airplane instruments to con­firm enhances safety because it provides con­ require use of LOTO, while in others the that the airplane is in a zero energy state. firmation that the airplane system is in a testing is done using airplane systems and These instruments include the central- safe condition for technicians prior to airplane displays and therefore does not maintenance-computer maintenance beginning maintenance activities. Tryout require control of hazardous energy. Where page and multifunction display. steps will be clearly identified in the LOTO is needed during airplane testing, the enhanced AMM. AMM test procedure will specify that LOTO ■■ Using test equipment to confirm that For example, in a 30-step deactivation is required. Personnel must be cleared from the airplane is in a zero-energy state. procedure in the AMM, Boeing is enhancing the area prior to energization and testing. Test equipment includes voltmeters, the AMM to clearly identify the tryout multimeters, ammeters, pressure require­ments in the deactivation procedure gauges, and test sets. SUMMARY (see fig. 3). TheAMM updates maintain a ■■ Performing a visual inspection to con­ continued focus on ensuring air carrier An airplane has many hazardous energy firm that lockout devices and tags are maintenance requirements for efficiency. sources that must be controlled before installed and that energy control devices technicians can perform maintenance are in the safe position. Lockout devices PROCEDURES WHEN PERFORMING activities. Boeing has developed proce­dures can include devices such as actuator AIRPLANE TESTING to protect factory personnel from hazardous collars, actuator locks, circuit breaker energy sources. These procedures will be collars, or locking pins. Energy control Hazardous energy control must be reviewed and relevant information used devices include circuit breakers, control implemented on the airplane system before to update the AMM in order to enhance handles, and control levers. the technician performs maintenance on hazardous energy control.A

24 AERO QUARTERLY QTR_04 | 14 www.boeing.com/boeingedge/aeromagazine