23 I & OPERATIONS The deadline for to comply with the GADSS mandate is 1st of January 2021. The mandate requires aircraft operators to automate aircraft tracking capabilities. The hardware options available for operators are reviewed here. The avionic options to comply with GADSS

he impetus for the International aircraft designs submitted after the updated to include new documents and Civil Organization’s introduction of the GADSS mandate must amendments pertaining to how data is (ICAO’s) Global Aeronautical be capable of timely FDR data recovery stored in distributed server networks, TDistress and Safety Systems in addition to having the standard such as a data-cloud and accessed and (GADSS) standards came from two high- recorders. used in an accident investigation. profile aircraft accidents. These were the The mandatory GADSS requirements Current Annex 13 legislation is based loss of Air France (AF) 447 in 2009 and will be effective from 1 January 2021. around flight data information, including the disappearance of Malaysian Airways its location during the post-flight location MH370 in 2014. and recovery (PFLR) phase. Despite flying in surveyed airspace at ICAO GADSS is defined as a performance- the time it went missing, AF447 was only A special multidisciplinary meeting on based approach, meaning the system is found about two years later. global (MMGFT) was graded on functionality rather than In 2014 MH370 was lost in the convened in May 2014 to propose mandating a specific solution. Indian Ocean, which is very deep in recommendations for future actions. One parts. Usual methods of accurately of the main decisions taken was the need locating the wreckage have so far been for operators to pursue aircraft flight- Background unsuccessful. tracking at a faster pace. Modern aircraft have the capability to Both these accidents raised the It further recommended that ICAO be connected by digital navigational question of how it is possible to lose track provisions should be developed, using a systems and satellites. Passengers can of an aircraft in the 21st century. multidisciplinary approach, to support connect to reliable onboard consumer The GADSS mandate will require the location of an accident site in a timely internet protocol (I.P.) service providers. operators to enhance and automate their manner for the purpose of search and Aircraft can now reliably access sufficient tracking capabilities for aircraft in rescue (SAR) and accident investigation. bandwidth for passengers to make video distress, and for aircraft flying off-course. ICAO document 10054 gives telephone calls and stream digital content. In addition, GADSS flight data implementation guidance for the GADSS Since 2010, the bandwidth available recovery will require the timely recovery requirements pertaining to ICAO for aviation purposes has increased of flight data after an accident by one of document Annex 6 – Operation of dramatically, due to improved satellite two modes. One of which is an automatic Aircraft – part 1 applicability. systems and better economic models; in deployable (ADFR) that Annex 6 was updated in accordance addition, transmitting basic telemetry has ejects its memory module when a crash is with the GADSS concept of operations become possible. detected. (ConOps) that specifies the high-level After the loss of AF447 in 2009, Air The other is the remote transmission requirements of GADSS. On 2 March France introduced a telemetry reporting of aircraft telemetry for downloading 2016, the ICAO Council adopted system through Aircraft Communications parametric data to ground-based servers. Amendment 40A to Annex 6, Part I Addressing and Reporting System Telemetry can be permanent, where including standard and recommended (ACARS). At the time the technology available for maintenance and fuel practices (SARPs) relating to the location available for sending satcom data monitoring, or triggered when an of an aeroplane in distress and the timely through ACARS was expensive. The abnormal situation is detected, with the recovery of flight data. basic prototype system adapted systems potential to include voice data when an These SARPs became effective on 11 that were already installed on the aircraft. aircraft is in distress. July 2016 and will apply from 1 January ICAO first adopted Amendment 39 to The introduction of the GADSS 2021. Implementation guidance is Annex 6 of its normal aircraft tracking mandate means all new aircraft must be available in document ICAO 10054. SARPS in November 2015. Phase one of forward-fitted with an enhanced ICAO Annex 13 – Aircraft Accident and the two-part requirement mandated automated tracking capability. All new Incident Investigation. This will be airlines to track its aircraft operating

ISSUE NO. 127 • DECEMBER 2019/J ANUARY 2020 AIRCRAFT COMMERCE 24 I AIRLINE & AIRCRAFT OPERATIONS under normal flight conditions every 15 continuously broadcasts unsolicited Consulting’s Hannes Griebel, Ph.D: “The minutes, with an optional abnormal position and other information, while advantage of using ADS-B for tracking tracking functionality. ADS-C is a requested information purposes is that you do not have to ICAO’s 2021 requirement mandates exchange via a dedicated ground or change anything on the aircraft. This is an autonomous distress tracking (ADT) satellite link. because the aircraft is already equipped function. This includes a requirement for ADS-B uses the secondary surveillance with a mandatory ADS-B transponder. the airline or a third-party organisation radar frequency in the L-Band at The ADS-B position report is broadcast to monitor and report abnormal tracking 1090Mhz. ADS-C transmissions need to approximately once every second. Even in events, such as an aircraft flying off- be requested (contracted) through areas with a lot of interference, this course. Airlines will be accountable for ACARS. ADS-C reporting is established translates to successful tracking update any tracking undertaken by a third-party between a specific aircraft and a specific intervals of much less than one minute in organisation. user through a dedicated digital most scenarios.” Tracking functionality does not communication link. Requests can specify Aireon’s approach to the space-based introduce change to current air traffic certain parameters, such as additional ADS-B solution uses high performance control (ATC) alerting procedures. information and reporting interval. payloads that sift through thousands of During the PFLR phase, tracking Space based ADS-B is the reception of transmissions made on the same requirements must guide SAR assets ADS-B broadcasts by satellite. The frequency. Spire’s satellites, in contrast, within six nautical miles (nm) of an aircraft will continue to broadcast ADS-B will identify overlapping signals by aircraft’s final point of impact. signals normally in the L-Band at simultaneously picking up overlapping If the aircraft enters an abnormal 1090Mhz. While the ADS-B specification broadcasts with a large number of situation such as an unusual attitude, relies on ground-based networks of ADS- receivers. Both systems have passed the speed or track it must go into ADT mode. B receivers, new satellite receiver proof-of-concept stage, and space-based This means the tracking standards move technologies make it possible to track any ADS-B is in now in the evaluation stage, from ICAO AN6 requirement 2015, to aircraft within range of a suitably nearing operational approval and GADSS ADT requirements. equipped satellite. introduction. The 2015 requirement is for an Satellite operator Iridium’s hosted While Iridium’s satellites are all in aircraft to transmit four flight dimensions payload programme did not initially place by now, Spire is still launching its of longitude, latitude, altitude and time, invite many users. Iridium created satellites. Spire’s ADS-B system will work every 15 minutes (4D/15) or less. ADT Aireon, a company that purchased the globally once the all the satellites are in stipulates an increase in the tracking rate hosted payload capacity on the new orbit and the network is complete. to 4D/1 specification, which requires a Iridium satellite fleet. The purpose of Because ADS-C can use any ACARS four-dimensional transmission rate of one Aireon is to provide dedicated air traffic link, aircraft have already been routinely minute or less. surveillance services through space-based connecting with via Other GADSS 2021 requirements are ADS-B. Originally developed by Thales satellite links for decades, in addition to for the timely recovery of flight data for Alenia Space Germany of Stuttgart, HF or VHF datalinks. Both Iridium and new aircraft type designs. Flight data Germany, high-performance space-based Inmarsat operate satellite data recovery could potentially occur in the ADS-B receivers as operated by Aireon communication networks that offer form of automatically deployable flight are primarily geared toward air traffic ACARS and ADS-C services. data recorders (ADFR) or flight data surveillance for improved air traffic The aircraft then sends its tracking streaming. management, but can also satisfy the information, such as speed and position, normal tracking requirement. down the priority link. Typically, an In contrast, satellite builder and operator sets up an ADS contract Satellite considerations operator Spire of San Francisco, between the aircraft and ATC. An established method to monitor California and Glasgow, UK has started Periodically an aircraft in flight will need aircraft is automatic dependent launching a constellation of hundreds of to cancel a contract, because the aircraft surveillance (ADS). Since the aircraft small, low-orbiting satellites carrying, can only have five contracts at a time. On knows its position from its navigation among other things, comparatively simple a long-haul flight the aircraft will systems, it can transmit this information ADS-B receivers with a view to offering a therefore establish and cancel contracts as to the ground. ADS is available in two space-based ADS-B service as part of it passes through different flight forms: ADS-B (B for Broadcast) and their aviation portfolio. information regions (FIR). ADS-C (C for Contract). ADS-B According to Griebel Aerospace “ADS-B can transmit flight level and

AIRCRAFT COMMERCE ISSUE NO. 127 • DECEMBER 2019/J ANUARY 2020 26 I AIRLINE & AIRCRAFT OPERATIONS

It is an operator’s own responsibility to track their aircraft. Aircraft tracking requires a transmition frequency of one minute or less in an abnormal situation.

must transmit aircraft 4D1 requirements during abnormal operations. According to Satellite Authorisation Systems’ managing director, Paul Roux: “Apart from the ADT functions and looking after the recovery of the FDR, we link our system to the 49 bus with a unique symbiotic relationship with the quick access recorder (QAR). We listen to all the information that is being sent from the QAR to the FDR, and use a database to look at the requirements and the minimum upper and lower limits specified in EuroCae ED-237 documentation.” The GCP can send pre- and post- flight information to the airline’s control centre via WiFi, satcom or 3G LTE. Connectivity means the GCP meets speed information. However, the system for any electrical circuit on the aircraft.” the requirement for the ADT device rides on the back of the legacy radar High-capacity lithium-ion batteries ground-based server to have the ability to network. There are more parameters with store a lot of energy, and when they fail collate data. The 429 and 717 bus are the ADS-C. It is possible to know the they can catch . Systems that cannot busses that provide the ED-237 data for aircraft’s next waypoint, and when it is be disabled in flight are not very popular, an ADT based system. expected to reach it,” says Griebel. but if the system can be disabled to The GCP system links to the FDR isolate a technical malfunction, then it wirelessly, where it will monitor ED-237 ceases to be tamper-proof. data as well as the required ADT Tamper-proofing If it is possible for pilots to manually parameters. The issue with using ADS-B is that it deactivate the ADT because the system “The biggest concern in the GADSS can be disabled, meaning that the system has malfunctioned, then it is conceivable mandate ICAO AN6 and from ConOps is is not inherently tamper-proof. From a for a person with malicious intent to the independence of the distress tracking 4D/15 flight tracking perspective, ADS-B deactivate the ADT and declare to ATN unit. There has been a recent consensus solutions will satisfy GADSS. However, that the flight is proceeding as normal. to change the tamper-proof wording in because the ADS-B system on board the the documentation to ‘inaccessible’. This aircraft can be disabled, it is likely that it is because of concerns raised by flight will not meet tamper-proof requirements. Global communications platform crews who did not want a tamper-proof One of the leading scenarios for Global Communications Platform system onboard the aircraft,” says Roux. MH370 is that a rogue crew member (GCP) is an independent device in terms The GCP is installed close to the flew the aircraft deliberately off course. of power, communications and aircraft’s ELT, so it is not accessible by On this assumption, a GADSS system navigation. It has its own independent any crew members in flight. From this needs to be tamper-proof and able to GNSS antenna, linkage and power. The perspective the GCP solution is unique activate itself. The tracking solutions in device connects to the aircraft power on because it is hard coded and self- operation typically have an overriding or by the battery bus or the powered, and therefore always activated. feature to allow the crew to manually secondary bus. It is possible for the GCP Unless an aircraft is in a maintenance activate and deactivate them. to operate for at least 65 hours without check, there is no ability to deactivate the The ICAO Committee is debating aircraft power in an emergency. system. When the unit is in a how to autonomously activate the The GCP is a standalone piece of maintenance check it will send a message system. equipment that meets the standards to the IOCC informing it of its “The wording around the activation stipulated in the GADSS tracking maintenance status. of ADT is relatively vague, and we are mandate. The 2021 requirement makes it The GCP is powered by a battery that debating how to capture the status quo in mandatory for all new aircraft to have an will exceed both the minimum size a document due out later this year,” ADT device installed. The GCP correlates requirement of the GADSS mandate and Griebel explains. “What does to the GADSS requirements, stipulating the minimum weight requirement. The autonomous mean? Autonomous means that operators must be fully responsible unit’s battery is self-sustainable. The that you have a system that cannot be for aircraft tracking. device is trickle-charged by the aircraft’s disabled if it catastrophically fails. Pilots Tracking solutions must meet several power and can identify if the aircraft’s and safety regulators can be suspicious criteria listed in ICAO doc 10054 and power is on or off. It will also take when you do not have a circuit-breaker ED-237, which stipulate that aircraft preventative measures to continue

AIRCRAFT COMMERCE ISSUE NO. 127 • DECEMBER 2019/J ANUARY 2020 27 I AIRLINE & AIRCRAFT OPERATIONS

It is believed the GADSS system needs to be tamper proof, and has to be able to activate itself.

operation for the duration of the flight. This requirement is aligned to the ELT functionality of 370 minutes. This means any ADT system that is installed on an aircraft will have to remain active for a minimum of 370 minutes. FDR logs many data sets that are typically looked at when the aircraft has an emergency. The GCP collects pre- determined values and has a sample rate of more than 1,000 per second. The GCP can monitor 12 different dimensions from an aircraft in flight, as opposed to the four that are required under 4D normal tracking conditions. articulated from by the flight crew, the This makes it possible to use an aircraft Using intelligent algorithms, the GCP airline will manually activate the aircraft’s in-flight entertainment (IFE) I.P. antenna can automatically detect when the ADT mode. to transmit and receive ACARS and EFB aircraft’s capacity to fly straight and level data for operational use. is impaired or out of sequence relative to International Air Transport ICAO guidelines. These include a set of Teledyne controls Association (IATA) and ICAO advisories pre-determined climb, descent and bank GADSS is not restrictive to airlines, stipulate that the system must have a angles; these are required because aircraft since it is possible for an aircraft to report minimal performance to use an ACARS manufacturers do not disclose the its position through ACARs every 15 network to carry safety related ACARS limitations of the and its minutes under normal tracking mode. messages. performance. ACARs has been able to report an Cellular Telephony with I.P VPN Once an aircraft in flight exceeds any aircraft’s position for a very long time via security performs a higher level than of the normal flight standards set by ADS. It is possible to send a position current HF, VHF or satcom services. ICAO, the GCP will automatically trigger report every 15 minutes from the multi- In Europe, US and other regions ADT mode. The system will continue to function control and display unit operators have been granted approval, report in ADT mode until the aircraft (MCDU) on the flightdeck for future air via a Teledyne special type certificate resumes a straight and level flight path. navigation system (FANS), or via (STC), to send ACARS information Part of the GADSS ConOps for ADT controller pilot datalink communication through an aircraft I.P IFE antenna. is the automated start and stop of (CPDLC) equipped aircraft that are flying Teledyne Controls GroundLink Data distress-tracking. long-distance oceanic routes, or long Link solution is designed to provide GADSS stipulates that there must be a overland operations. ACARS over IP using cellular capacity for the ADT to be activated It is possible to configure GroundLink connectivity on the ground via the from the airline on the ground. If the Comm+ to collate and report all the GroundLink Comm+ unit which is ground operator notices something information required for the GADSS already installed on thousands of aircraft. untoward with the aircraft it will be mandate. The GroundLink Comm+ when To continue to send and receive ACARS possible to start ADT transmissions. connected to an IP satcom system will be over IP in flight the aircraft has to be GADSS specifies that the source must able to send a 250-parameter data equipped with an IP satcom link with activate and deactivate ADT. This means stream, and to configure the frequency internet connectivity. that it is only permissible for the airline over which the data is sent. “Instead of ADT being activated in a operational centre that activated ADT It is also possible for every ACARS distress situation, information will manually to deactivate it. If the aircraft message to include the aircraft’s position. continuously flow to the airline. In triggers ADT mode, only the aircraft can According to Teledyne Controls, addition, the relevant data can be deactivate it. senior director of aircraft solutions, automatically streamed directly to When an aircraft deviates from its Murray Skelton: “We can transmit aviation regulators,” says Skelton. “There flight plan it is likely that the aircraft will GADSS, ADS and all the ACARS traffic are so many more things that the airline still be flying in a controlled manner, so over an I.P. link. Using an ACARS over would like to monitor, such as fuel burn, ADT will not automatically trigger. I.P. link over all the current ACARs links engine core temperature, and many more GADSS stipulates that the airline must be is advantageous because it is secure and data sets way beyond those required for fully responsible for tracking its aircraft. fast.” GADSS.” Therefore, a notable deviation from Teledyne Controls developed a system Information is transmitted through the aircraft’s planned course must be that uses the passenger information and inexpensive channels, so much more data identified by the airline’s control centre. If entertainment system (PIES) domain I.P. can be sent in real time from that aircraft. communication is lost, or a sufficient data source, and links it to the Aircraft Furthermore, GroundLink Data Link+ reason for the deviation cannot be Informational Services (AIS) domain. will reduce the ACARS usage cost,

ISSUE NO. 127 • DECEMBER 2019/J ANUARY 2020 AIRCRAFT COMMERCE 28 I AIRLINE & AIRCRAFT OPERATIONS

The Teledyne GroundLink Comm+ can collate and report all the information required to satisfy the GADSS tracking mandate.

collecting, processing and delivering data. It will do this in accordance to the rules it has been given,” says Skelton. “It is not possible to data-load the system in flight to corrupt its operation. The system can only be data-loaded and reconfigured when the aircraft is on the ground. Once the aircraft is in the air it will fulfil the preloaded requirements of its configuration.” In flight it is possible to ask the unit to send specified data sets, and to set codes. The Next Generation unit can send detailed reports when requested. because the system transmits data via the communication. However, data capacity FDR recovery IFE system. Typically, IFE data is pre-paid across the Iridium network can be small. ARINC 717 is a standard for the data in the terms of (gigabyte) GB usage. In many cases a lot of the IFE satcom parameters that are sent from the Companies such as Inmarsat are providers have good global coverage. acquisition unit to the FDR. Airlines can developing business cases to lower the There is a new generation of satcom add more parameters to the 717 data set cost of in-flight broadband usage to make services being introduced, yet it will take for specific monitoring. Some airlines it more viable for the complete connected time before there are enough satellites regularly monitor the 717 data stream aircraft. online for complete global coverage. because they want to observe procedures, The ADS-B transponder can be used It is not possible to use distress- such as (APU) on for ADT, although the system must be in tracking everywhere, because there are and off times. This is useful, because they range of a ground signal or satellite, holes in the satellite coverage. do not want crews to over-use the APU depending on the aircraft’s connectivity Teledyne Controls’ Next Gen system while on the ground to prevent fuel system. will have the capability for the airline to wastage. All aircraft transmit an individual set a range of parameters that under The frame speed is the rate the data is four digit transponder code that is called certain conditions trigger data sets for recording in words per minute. An a SQUAWK code. The unique code is distress and abnormal tracking and also aircraft’s frame speed increases as aircraft assigned by ATC and enables them to stream additional become more parameter-rich. identify the aircraft. In an emergency it is monitoring data. “Frame rates can be 256 words per normal for flight crew to change the “If there is a cabin pressure anomaly minute to 512, to 1,024 words per aircraft’s SQUAWK code to a distress and the cabin pressure has dropped minute. Frame rate relates to the samples setting, in order to inform ATC of the below an acceptable level, then this will the aircraft is taking per minute. emergency. trigger an emergency data set to be sent Improving the frame per minute rate If the captain sets the aircraft’s to a specialist within the airline. It is also improves the granularity of the data transponder to an emergency SQUAWK possible to send the data directly to the recorded,” says Skelton. “If you start setting, then ACARS will transmit original equipment manufacturer (OEM) streaming 717 data from the moment the additional GADSS tracking data. The so that it too can monitor the aircraft leaves the ground to when it aircraft must be in ACARS range, which symptoms,” says Skelton. lands, at a frame rate of 512 words per is not always possible, even if the aircraft The ground-based specialist can minute, it will have recorded 1 megabyte has satcom and HF. This is because there decide if the aircraft continues its flight or (MB) of data per flight hour.” are parts of the world where ACARS will lands at the earliest opportunity. The This means that transmitting full 717 not operate and there is no satellite system will also automatically trigger the data across a satcom network can be coverage. Subsequently there is not distress-tracking mode function. expensive. always a guarantee the ADT information Access to the flight plan data makes it Currently, the data has to be transmitted will be received. possible to know if the aircraft is recovered manually from QARs or via L-Band does not have complete global deviating off course. This is as well as the cellular transmission on the ground coverage. There is no system that is distress function being activated by at the end of a flight using a wireless 100% infallible. However, the system ACARS. The system will then alert the quick access record (WQAR) like the that has come closest to global coverage relevant airline departments and aviation GroundLink Comm+.However as data is the Iridium satcom network. authorities. costs reduce for satcom services the Many airlines use the Iridium “There are no switches on the business case for airlines to stream the network because they know that flightdeck that can activate or deactivate full 717 data in flight becomes more wherever they are in the world their the GroundLink Comm+. It is an attractive. Obviously the implications for aircraft will always have voice or data autonomous unit that is designed for both safety and operational

AIRCRAFT COMMERCE ISSUE NO. 127 • DECEMBER 2019/J ANUARY 2020 30 I AIRLINE & AIRCRAFT OPERATIONS

It is possible that operators will want to retrofit legacy aircraft to GADSS 2021 standards for commonality purposes.

information to the flight operations centre. In the event of an alert onboard, the aircraft notifications are automatically sent to all applicable personnel. Notifications can be e-mail alerts to mobile phones or PDAs. Engine Condition Trend Monitoring (ECTM) will monitor the aircraft’s engines. The system monitors the engines for damage, deterioration and excessive wear. AFIRS records and transmits real-time flight data enhancing flight operations quality assurance (FOQA) datasets. In the event of an in-flight emergency, AFIRS will transmit FDR data in real time over improvements increase with a live data Information Recording System (AFIRS) Iridium. stream from the aircraft. product interfaces with a customizable Most satcoms have a variety of “Looking at other data types on the variety of aircraft databuses in addition ARINC 429 inputs, a processing unit and aircraft, the CVR data is another data to being able to monitor the output to the the ability to host additional software. source that could be streamed but good flight data recorder similar to standalone “We have taken the step to incorporate a quality sound is needed for this, as you QAR. It is possible to remotely upload downlink capability within the hosting are not just listening to the pilots’ voices. ADT compliant 4D tracking and distress function, so it is effectively hosted on a Background noises need to be recorded monitoring algorithms to aircraft that satcom. This is to enable the satcom to and analysed in the event of an accident. already have an AFIRS unit installed. To move the data from the aircraft and send But there is no reason why CVR data and achieve full compliance, the AFIRS it to the airline over I.P.,” says deRis. cabin surveillance data cannot be system on the subject aircraft must “Real-time aircraft health monitoring is delivered by the same IP links,” says already be connected to the appropriate possible as well, enabling airlines to Skelton. databuses to trigger the ADT function, perform dynamic cost indexing. The The next generation of GroundLink for example those containing pitch-and- system can take information from the will be able to trigger and activate airline roll parameters. (FMS) as long defined data sets compressing and “For the retrofit market, if a customer as there is the appropriate output from sending the data to ground systems both would like to achieve the same capability the system.” airline, OEM and regulatory via a secure from GADSS, there are existing units that It is also possible to set AFIRS I.P. VPN potentially adding and FLYHT produces that can better flight- parameters to increase the aircraft enhancing the mandatory GADSS distress track an aircraft than the current ADS-B tracking rate and send alerts to the airline packet set. In the future, using secure IP requirement,” says deRis. “It is possible in the event that the aircraft deviates from links and systems like the GroundLink to configure the AFIRS unit to record and its flight plan. will mean that all aircraft data, including transmit GADSS ADT information. The Currently, this capability is manually voice and video, could be delivered in real number of recordable parameters activated and deactivated; however, with time as a continuous data stream from depends on the age of the airframe and the inclusion of the distress monitoring the aircraft. the number of databuses available. AFIRS algorithms, it can be automated. Power can use data from ARINC 429 standard schemes are being evaluated to notify the and ARINC 717 standard buses.” airline should a tamper situation occur. FLYHT AFIRS can simultaneously monitor The GADSS autonomous distress databuses by a variety of custom-written tracking mandate is associated with new algorithms. The standard unit offering Data recovery aircraft entering service in 2021. OEMs includes satcom, allowing real-time The FLYHT stream service has the have indicated that they have selected the global coverage, meaning it can send capability to recover FDR information. technology to meet the GADSS 2021 information to a flight operation centre. Once activated, FLYHT increases the tracking mandate. AFIRS 228S provides complete number of reports and streams the FDR According to FLYHT, manager of aircraft visibility that will yield aircraft data to an airline. The ground system products, Matt deRis: “Because Boeing management information. The AFIRS is will collect the data and make it available and Airbus have chosen a different installed in the bay and can through a user interface. technology path forward for ADT monitor engines, avionics and navigation “If you trigger the FDR streaming solutions, we stepped away from systems, or anything with a standardized because of a certain event, then you will satisfying the mandate directly, and are output. This flight data is automatically get the data stream pertaining to that focusing on retrofit solutions.” transmitted over the Iridium network to event. This data will be used as a back-up FLYHT’s Automatic Flight servers on the ground that forward the to the FDR,” says deRis. “Yet streamed

AIRCRAFT COMMERCE ISSUE NO. 127 • DECEMBER 2019/J ANUARY 2020 31 I AIRLINE & AIRCRAFT OPERATIONS

The ADFR deploys when the aircraft enters and unusual attitude. The units floats on the water and transmnits its location.

FDR data may not necessarily capture all the information from the start of the flight up to the point that the accident took place. We are in the process of developing new hardware products to fill a gap between the time before FDR recovery and the event.” The Iridium network can stream data at a maximum rate of 2.4 kilobytes (Kb) per second. It is possible to stream live FDR in flight or by sending packets of information during an emergency situation event. Streaming historical data is challenging because a large amount of data needs to be sent in a short period of time. The FDR will record all the required provide a minimum of 150 hours of datasets from the beginning to the end of Deployable FDR 121.5MHz homing. This extended flight. In an emergency the FLYHT Applications for new aircraft designs duration is to ensure that the ADFR is solution makes it possible for the system must have a capability to retrieve FDR easily recoverable in periods of bad to backdate and off-load a significant data as part of a GADSS requirement weather or high sea-state. No special portion of the FDR data. This download pertaining to PFLR. If an OEM applies equipment or processes are required to data could include all FDR data sets for for a new type certificate after January locate and recover an ADFR in oceanic the 20 minutes before the end of the 2021, then it must to adhere to FDR regions. For on-land events, the ADFR is flight. recovery regulations. equally recoverable and survivable. “Because timely recovery of flight One prominent idea is for OEMs to One of the benefits of a deployable data (TRFD) and ADT is not mandated deploy the FDR memory modules from recorder is that no new technologies are for all aircraft and is only required for the aircraft. In a runaway distress required to support search and recovery. new aircraft, airlines are reluctant to situation, the automatically deployable The deployable recorder contains an invest in systems and procedures that flight recorder (ADFR) deploys from the integrated dual-frequency ELT that would be applicable for their entire fleet,” aircraft at the point of impact or transmits a GNSS-enabled 406 MHz says deRis. “If TRFD becomes immersion in water. Once deployed, the distress frequency, and a 121 MHz compulsory for current fleet types, then ADFR will float on the ocean, homing frequency. The GNSS-enabled retrofit solutions that encompass the transmitting its location until it is 406 MHz distress frequency (post- recovery of all data will gain traction, recovered. deployment) can be tracked by the because the airline must make the (SAR) authorities, COSPAS-SARSAT satellite system to investment.” globally, have been routinely recovering within a radius of 10 metres. There is an economic issue for airlines deployable recorders from military The 121.5 MHz frequency is the to stream this data. The technology is aircraft since the early 1960s with high ubiquitous global standard for SAR available, but the business case for success. The ADFR’s emergency locator Homing and can be used by aircraft or steaming FDR data will become more transmitter (ELT) is integrated with the ships, including non-SAR assets, to Home attractive to airlines when available CVR-FDR memory. and locate the deployed ADFR unit. bandwidth increases and satellite There is a near perfect record of Because the system relies on the proven communication service providers improve recovery of this product with (military) COSPAS-SARSAT global SAR per-byte-prices. transport aircraft types. infrastructure, no new policy or practices “Based on recent events pertaining to History has demonstrated the are required to locate and retrieve an FDR recovery, there is a growing reliability of deployable recorders in land ADFR from water or land. sentiment that the technology exists now, and water incidents from military The ADFR intends to provide and that there is less and less reason why aircraft. Since starting to keep records in position updates throughout the (in-fight) we should not retrofit all existing aircraft 1967, Leonardo DRS deployable distress event (this capability in-flight is with the capability for FDR recovery,” recorders have been involved in 25 CAT not confirmed yet); and at the location of says deRis. ‘A’ transport aircraft events. In one event the point of end-of-flight. Once deployed, It is forecast that more airlines will the deployable did not deploy due to the ADFR continues to provide GNSS- want to retrofit their legacy aircraft to improper installation by maintenance enabled ELT transmissions, along with GADSS 2021 standards for commonality personnel. the 121.5 MHz Homing frequency. purposes. This is because airlines will The ADFR is designed and tested to The deployable FDR with its integral want to narrow the technology gap extremely onerous crash requirements to ELT helps a SAR Agency to confirm the between new forward-fitted GADSS- ensure post-event survivability. ‘Location of End of Flight,’ thereby compliant types and older aircraft. The ADFR’s ELT is equipped to improving response time to the accident

ISSUE NO. 127 • DECEMBER 2019/J ANUARY 2020 AIRCRAFT COMMERCE 32 I AIRLINE & AIRCRAFT OPERATIONS

Aircraft can fly a long distance and cover a large area in one minute’s flying time. Transmitting tracking information at one minute intervals still means an aircraft in distress can be in an area the size of London.

In addition, data can be retrieved and updated via the Recorder Interface Unit (RIU), which allows easy access to maintenance personnel. Again, no additional maintenance action is needed, because it is the same accessing the deployable recorder in the aft position. Airbus is focusing on a line-fit deployable recorder solution for its commercial programmes.

Conclusion For airlines it is not just the effective date of the GADSS mandate that is important. One of the biggest concerns for airlines is the uncertainty of the site. Having both the location of the end weight delta associated with the available systems. Airlines are worried of flight and subsequent position installation of an ADFR if that device because the stricter the mandate, the ‘updates’ as the ADFR ‘drifts’ at sea also replaces a separate ELT. The ADFR more it will cost to make fleets compliant. substantially improves the probability of does not place additional maintenance Airlines such as Hawaiian Airlines are locating survivors, aircraft wreckage and burden on the aircraft. progressive in their approach. They are the ADFR in a timely manner. An ADFR Unlike telemetry systems relying on already coming up with ideas on how to can minimise the search phase of a SAR either Inmarsat or Iridium, ADFRs make implement GADSS. Other airlines are event, and allow authorities to focus on use of the international COSPAS- researching viable options. Yet some rescue and recovery. SARSAT satellite constellation comprising airlines want to avoid it all together. It is still required to install one fixed the LEO, GEO and MEO star satellites Aircraft flying in European and North combination recorder (CVDR) in the ensuring robust 100% global coverage American airspace will be tracked by aircraft. The L3Harris Technologies with a single satellite network. ATC. Airlines operating over these CVDR is part of the ADFR system. ADFRs have the ability to continue to regions will not be required to make The L3Harris/Leonardo DRS record flight data throughout the distress changes to their legacy fleets, and can rely voice data recorder (CVDR) system phase including during rapid changes in on comprehensive network coverage achieves this requirement by installing a flight altitude. Telemetry connections can offered by ATC. Tracking aircraft is fixed combination-recorder in the be compromised with rapid changes in important when they enter oceanic forward avionics bay, and a deployable flight pitch and altitude. ADFR ELT airspace. combination-recorder in vertical tail increases the ability for search and rescue AF447 was transmitting a position fix plane (VTP). teams to rapidly locate potential every 10 minutes before it crashed, and it Each unit records all of the voice and survivors of downed aircraft, particularly took two years to locate the wreckage. flight data, ensuring that in any accident over water. An aircraft in a gradual descent is capable situation the recovery of at least one COSPAS-SARSAT is a multi- of travelling a great distance in one recorder will provide all required data to government funding global SAR service, minute. Tracking even at one-minute the accident investigation authorities. free to all users of an ADFR. When intervals could mean a SAR area almost Airbus’ safety requirements for non- telemetry data is unavailable, the ability the size of London. commanded deployment ensure an of a deployable recorder to float on water There are places in the world where extremely robust safety factor during eliminates the large cost of an underwater aircraft can disappear. Because gaps in flight. There are no known reports of a search for the black box and provides the satellite network are typically not deployable FDR in military service quick access to critical CVR/FDR data greater than seven minutes’ flight time, it causing injury or damage. post-event. is still possible to meet the normal The international aviation community Like all flight recorders, an ADFR is mandatory flight tracking requirement by has worked under the leadership of subject to the periodic data read-out of sending a position report every 15 EUROCAE to develop and issue the the memory in accordance with national minutes. minimum operational performance airspace regulation. When technology advances and more specification (MOPS) for flight recorders An ADFR has similar scheduled satellites are online, it is likely that both (ED-112A). This document sets out the maintenance to that of a fixed recorder normal tracking and ADT transmission requirements for operational performance and ELT-AF. A fixed recorder and ELT- frequency will be increased. of all flight recorders including ADFRs. AF, each need to have their respective An ADFR installation is similar in battery’s replaced on a five-year schedule. To download more than 1,200 weight to a fixed recorder and ELT- The ADFR has one battery for the ELT, articles like this, visit: Automatic Fixed (ELT-AF). There is no which is replaced on a five-year schedule. www.aircraft-commerce.com

AIRCRAFT COMMERCE ISSUE NO. 127 • DECEMBER 2019/J ANUARY 2020