All aircraft with type certification later than Jan. 1, 2021, weighing more than 60,000 pounds and capable of transporting more than nineteen passengers must feature the ability to autonomously transmit aircraft position reports minute-by-minute when flying with conditions considered to be life-threatening to passengers and flight crews onboard.
This concept is known as autonomous distress tracking (ADT). It becomes applicable under changes related to the Global Aeronautical Distress Safety System (GADSS) that the International Civil Aviation Organization (ICAO) first adopted to its Annex 6 aircraft operating standards and recommended practices in 2016.
Right now, civil aviation regulators continue to enact mandates requiring aircraft position reporting requirements that operators must meet aimed at complying with those changes. The latest ADT policy updates have come from the FAA in the U.S. and the General Civil Aviation Authority (GCAA) of the United Arab Emirates (UAE).
On Feb. 4, the FAA published an Information for Operators (InFO) notification, which are regularly issued when low-urgency regulatory, administrative or other airspace system related changes are in development. In the InFO, the agency states that “the GADSS recommendations will be addressed in future FAA guidance,” an indication that the agency is still developing the final regulatory approach it will take toward regulating ADT equipage requirements.
The InFO goes on to refer operators to circular 347, which provides a detailed analysis and definition of ICAO’s aircraft tracking implementation guidelines.
Operators of aircraft registered in the UAE will be subject to a notice of proposed amendment to GCAA’s civil aviation regulations published on Dec. 25, 2018. One of the ADT requirements GCAA is considering within the proposed amendment is not only to require operators to track their aircraft minute-by-minute when under distress, but what exactly a distress condition is.
Under the proposed amendment, operators need to be able to describe their aircraft tracking system and how it identifies abnormal flight behavior. That identification of abnormal behavior needs to then be remitted to an air traffic service unit. Emergency response plans for airlines also need to be updated to reflect their ability to meet each of these requirements.
GCAA’s proposed regulatory changes define abnormal flight behavior as aircraft conditions “outside of the parameters defined by the operator for normal operations” or “which indicates an obvious deviation from normal operation.” Additionally, distress is defined by GCAA as a condition that the operator has determined “poses a risk for the safe continuation of the flight or for third parties.”
The agency is requiring operators to meet its minute-by-minute ADT requirements, which are still being finalized, by June 1, 2019.
China, Europe, Singapore and India are the other flight information regions where civil aviation regulators have already enacted autonomous distress tracking regulation in the form of airspace avionics performance requirements.
Technologies Are Ready Today
Airlines are already adopting new technologies to meet the 2021 autonomous distress tracking requirement. In some cases, modification of aircraft electronics or operating software is required. In other cases, an update to the way their web-based flight data monitoring technology of choice triggers automatic streams of distress data off an aircraft are all that’s needed.
Etihad Airways is subject to GCAA’s proposed June 1 deadline for newly-proposed aircraft position reporting regulation. The airline, which operates a mixed fleet of 115 Airbus A320, A330 and A380s and Boeing 777/787s, on March 27 said it had completed the implementation of SitaOnair’s Aircom Flight Tracker system, which utilizes FlightAware data services to provide the position, speed and altitude of every in-service Etihad airplane.
The Aircom system satisfies the autonomous aspect of distress tracking by detecting and capturing specific ACARS messages that would indicate the aircraft is operating outside of its normal flight envelope. Additionally, it can provide alerts to Etihad’s flight operations or dispatch centers if the aircraft has deviated from its planned route.
By implementing Aircom, Etihad is also adopting FlightAware’s “GlobalBeacon” autonomous distress flight tracking technology, which combines the FlightAware aircraft data processing platform and web-interface with Aireon’s space-based ADS-B network to provide up-to-the-minute aircraft position reports.
“Globalbeacon will use the constellation of Iridium NEXT satellites to pick up the ADS-B Out signal that all Etihad aircraft are transmitting,” said Borja Roiz, a senior avionics and electrical systems technical engineer for Etihad Airways. “This solution does not require any additional equipment to be installed on the aircraft as they are all transmitting the ADS-B Out signal.”
Much like Etihad’s non-hardware-based adoption of SitaOnair’s Aircom system, there are other software-intensive autonomous distress tracking technologies available to airlines as well. Texas-based Sabre, for example, provides flight following and aircraft data management software that enables minute-by-minute autonomous distress tracking with no avionics upgrades required.
Sabre’s ACARS Manager is an aircraft communications management software that can interface with every and all aircraft data link service provider networks, including those using satcom and very high-frequency radio on oceanic or polar routes. The position reports generated through this software are displayed to an operator on a Gantt chart and a moving map display depicting the flight path of the aircraft.
The company is meeting the autonomous distress tracking requirement by analyzing the ACARS messaging set coming off of the aircraft.
“We’ve found it’s possible to determine whether an aircraft has had an electrical failure or an engine is out of parameters or another distress condition based off the ACARS messaging data that’s coming down from the aircraft,” said Richard Landeck, global supervisor of Sabre’s airline solutions division.
“The other thing we’ve done in a new version of ACARS Manager that we’ll be releasing very shortly is to enable the ability to establish an ADS-C contract with the aircraft,” he said. “We can establish that contract with the box on the aircraft through ADS-C to program the aircraft from the ground to transmit a position report every minute. Then when the aircraft lands that contract is automatically cancelled, it terminates [and] does not stay with aircraft after it lands, we have a few customers testing that right now.”
Elsewhere, some avionics makers have already proven their ability to meet minute-by-minute tracking requirements in flight technology demonstration projects, a list that includes Canadian manufacturer and aircraft data streaming service provider FLYHT.
The company demonstrated this capability during the 2018 Boeing ecoDemonstrator program, where a FedEx 777 was equipped with its Automated Flight Information Reporting System (AFIRS) satellite communications computer. The AFIRS system uses a proprietary software known as the embedded launching application to determine what information an airline wants to capture about its aircraft’s performance.
That application also compresses the collected data before it is transmitted across Iridium’s satellite system and down to the company’s cloud-based Uptime server, where the file is unzipped and distributed to an airline’s maintenance or flight operations department in an actionable format.
“The ARINC 717 data, the same data that goes to the FDR, is going to the AFIRS unit,” said Kent Jacobs, director of advanced applications for FLYHT.
Some of the automatically triggered conditions that were set for the trial included unusual attitude, a bank angle above 30 degrees or a pitch exceeding 15 degrees lasting more than 2 seconds. If the AFIRS system detected any of the pre-defined conditions occurring throughout the flight, it would autonomously trigger a streaming session of 1,024 words per second using Inmarsat’s Swiftbroadband satellite network.
During the ecoDemonstrator trial, the AFIRS unit was configured with both an internal inertial navigation system to detect when pitch, attitude or ground speeds should be triggered, streamed and monitored. Jacobs said they also used the system to stream cockpit audio in real time.
Operators can also use the web-based interface to view a real time three-dimensional depiction of the aircraft’s flight path and changes to its cockpit display information.
“When systems on the aircraft feeding the flight data recorder and AFIRS are working perfectly, autonomous detection can involve analysis of data from the aircraft, so all 1,024 words per second being recorded to FDR are being analyzed by AFIRS for any event,” said Jacobs.
According to Jacobs, if the aircraft were to lose power and the AFIRS unit has an external battery or other power source, it could continue to run on its own external battery and still generate distress data transmissions using the system’s internal Iridium radio.
“We’ve done successful integration testing with Swiftbroadband Safety, ViaSat, SmartSky Networks, our system is completely agnostic we can interface to virtually any connectivity pipe off the aircraft,” said Derek Graham, chief technical officer of FLYHT.
Another approach to enabling ADT operations is provided through a new breed of emergency locator transmitter (ELT) technology.
Paris, France-based aircraft ELT manufacturer Orolia is leading the deployment of this technology, as it is in the final stages of certification for its new “Ultima” distress tracking ELTs for Air France’s fleet of Airbus A320s.
Their new ELT system is lithium ion battery-powered with an internal antenna capable of transmitting 406 and 121.5 MHz signals. The antenna also has embedded global navigation satellite system reception and Orolia also provides a separate ADT module that gets installed within the aircraft’s cockpit control panel. When the ADT module captures a distress signal or condition and transmits it to the ELT, a a distress message can be remitted to air traffic controllers, search and rescue agencies and the aircraft operator’s ground-based personnel. The module’s signaling of a distress condition then also triggers minute-by-minute tracking.
In the event of an aircraft experiencing a power failure, the new ELT still transmits distress signals to the COSPAS SARSAT satellite system, which has provided free search and rescue satellite emergency locator service to the aviation industry for more than two decades.
“The idea is to have the distress trigger occur in-flight before the aircraft crashes,” said Christian Belleux, director of Orolia’s aviation and military product lines. “The previous generation of ELTs were activated by G forces at the impact of the crash.”