GADSS: WHERE ARE WE NOW?

The aircraft tracking element of the ICAO’s Global Aeronautical Distress & Safety System (GADSS) initiative has consisted of multiple phases since its inception following the loss of MH 370. Phase one was that related to aircraft tracking, this was followed by phase two on autonomous distress tracking, the latter phase is the one on which international rule making is currently concentrated.

Developments at ICAO

According to Kailey Campbell from product marketing at NAVBLUE – an Airbus company, phase one was implemented as planned. “Indeed, it is already a requirement for airlines to have a flight tracking system, like N-Tracking, that can meet the 4D/15 requirement. 4D stands for latitude, longitude, altitude and time, while 15 stands at least every 15 minutes,” she says.

Jessie Hillenbrand, director of marketing and public relations at Aireon, says that the recommendations for when an aircraft is in distress are that the aircraft needs to be tracked once per minute. “This recommendation has been delayed by ICAO due to industry input on needing more time. It was delayed from 2021 to 2023,” she says.

Indeed, ICAO is continuing to develop the location of aircraft in distress repository (LADR). “LADR is a secure, web-based storage facility which collects, stores and makes available to subscription holders position information supplied from autonomous distress tracking (ADT) transmission devices (such as ELT DT or SATCOM),” says Ruben Stepin, director of airline business development at Skytrac. “This is to ensure that operators can comply with ICAO Annex 6, which states that the operator shall make position information of a flight in distress available to the appropriate organisations, as established by the state of the operator.”

Available options

Hillenbrand observes that there are few technologies, apart from Aireon’s space-based ADS-B that can do the one-minute distress tracking globally. “This requires high-fidelity data at a high-update interval, with low latency,” she says. “Over landmasses and densely populated areas, this should not be an issue with ample access to ground-based systems. Aireon can also provide this capability over remote, oceanic and polar areas on a global basis.”

The FLYHTMap ASD aggregates a wide array of incoming data into an optimized display and complies with the normal aircraft tracking needs, FLYHT says. FLYHT image.

As to the GADSS autonomous distress tracking (ADT) standards and recommended practices (SARP) that are being worked within ICAO, air navigation service providers (ANSP) and airlines, Aireon is recommending ADS-B to serve as the ADT functionality or purpose, as the industry is hesitant to have to implement any additional aircraft retrofitting. “Emergency locator transmitters (ELT) are also being considered for this SARP, however they will require retrofitting,” says Hillenbrand.

FLYHT’s system with AFIRS and their aircraft situation display FLYHTMap complies with the normal aircraft tracking needs, observes Derek Taylor, vice president of sales and marketing at FLYHT Aerospace Solutions. “Additionally, we could support the trigger points for ADT; however, since this is a forward fit requirement, we have not seen much demand for it in the marketplace. The larger aircraft original equipment manufacturers (OEM) have a solution for this using ELT distress tracking (DT) and the COSPAS-SARSAT system,” says Taylor.

NAVBLUE’s N-Tracking is already GADSS compliant, this means it will receive position reports from aircraft at least every 15 minutes and 1 minute or less in a distress situation, according to Campbell. “N-Tracking with Aireon space-based ADS-B will get a position from an aircraft every minute at all times. So, we are meeting the more stringent requirement without a need to trigger an ‘abnormal operation’. Airbus has also defined specific ACARS messages to trigger one minute reporting for airlines not using Aireon, and we can trigger this too,” she says. “Both airlines and OEMs are looking for ways to consider the distress mandate and how to comply which requires additional testing and manufacturing. For example, Orolia is working with Airbus to provide ELT-DT for all Airbus aircraft,” she says.

Indeed, Boeing awarded ACR for their ELT DT transmission device, according to Stepin. “On the SKYTRAC’s side we were awarded the Large Value Contribution (LVC) for the National Research Council of Canada Industrial Research Assistance Programme (NRC IRAP) to develop GADSS and aircraft health monitoring further,” he says. “We are developing an onboard ADT triggering device that detects distress states in real-time while meeting the strict EUROCAE ED-237 requirements and the ARINC 680 report, which describes the technical requirements, architectural options, and recommended interface standards to support an onboard ADT system intended to meet global regulatory requirements for locating aircraft in distress situations and after an accident.”

AOC Responsibilities

ICAO’s GADSS SARPs are to be implemented by the regulators in their own region of competence. Each regulator can have its own way of implementing the GADSS SARPs. “At Aireon, we have a product that we have jointly developed with FlightAware to meet all of the GADSS requirements—with the exception of the ADT aspect, since that has yet to be determined,” says Hillenbrand.

The product developed by Aireon and FlightAware is called ‘GlobalBeacon’ and it is a dashboard that tracks an entire fleet of aircraft and has customizable alerts that can be edited depending on altitude and communications transmission. “It will trigger alerts if there is anything abnormal. The service also provides instant distress notifications, which facilitates communication between the operator and air traffic control (ATC) with constant fleet monitoring, automated distress alerts and tools that make it easy to share information when needed,” says Hillenbrand. “Also, since GlobalBeacon utilizes Aireon’s space-based ADS-B data, the update interval on all ADS-B equipped aircraft is one minute or less, already meeting the 2023 aspect of the GADSS mandate. Airlines would be the main users of this tool.”

The Aireon and FlightAware collaboration is called GlobalBeacon. Aireon calls it a turnkey solution for compliance with the International Civil Aviation Organization (ICAO) Global Aeronautical Distress Safety System (GADSS). Aireon image.

NAVBLUE’s N-Tracking is already GADSS compliant. It will receive position reports from aircraft every 15 minutes and one minute or less in a distress situation. NAVBLUE image.

Indeed, GADSS normal aircraft tracking users are primarily in commercial airline or air cargo operations, observes Taylor. “There are some needs for corporate operators to want to know where their high value passengers are located at all times, but the primary ‘user’ are AOC personnel at the individual airlines,” he says. “ADT users are mission control centres (MCC) which receive alerts and forward them to rescue coordination centres (RCC). There are also ancillary users in the AOC so that they know of issues with their aircraft, but they are not the primary users.”

What happens from an operational point of view is that the transmissions are sent to the operational control center (OCC) where a dispatcher or flight follower can track the aircraft. “The process is straightforward for the user when using N-Tracking, the system is designed to report the position and if a report is not made within 15 minutes, an alert is generated for the dispatcher to take action,” says Campbell.

Stepin highlights that with SKYTRAC’s SkyWeb web-based aircraft tracking software an airline can be compliant with ICAO’s aircraft tracking implementation guidelines for aircraft tracking and alerting. “Utilizing SKYTRAC’s onboard SDL-350 broadband transceiver an airline can opt to use one second resolution of position reports every minute, based on the global Iridium Certus satellite network,” he says. “The user knows exactly when the next position report is due to arrive, and — in case of a missed position report — the user is able to interrogate the onboard system immediately to determine the status of the device, satellite network and aircraft.”

The benefit of GADSS is that now airlines are responsible to track their own aircraft, which was not mandatory in the past, observes Stepin. “Typically, in the past ATC had the best understanding of an aircraft location as they would monitor aircraft separation in their airspace jurisdiction. But they were never responsible to track the aircraft. The benefits for an airline to track the position of their aircraft increases the safety of flight as significant deviations from planned flight routes can be monitored with more scrutiny,” he says. “However, this gives the passenger the most benefit and peace of mind, to know that every airline one flies with now knows the location of the aircraft’s position, at least every 15 minutes, so that in case of an emergency the respective airline knows the last known location before the emergency.”

Other GADSS stakeholders

With phase two on ADT, the OEMs are also direct stakeholders of the GADSS initiative as they are required to meet the ICAO recommendations, with aircraft with certificate of airworthiness first issued on or after 1 January 2023 required to ‘autonomously’ track an aircraft in distress, highlights Stepin. “Again, the airline is responsible to track their aircraft when in distress. This will benefit the airline as in the event of a distress situation they can inform relevant authorities and entities much more in advance, in the event of a distress situation, allowing for better real-time support and dispatching of necessary support assets,” he says.

Looking into phase three of GADSS, there will also be requirements for the timely recovery of flight data, whereby OEMs are required to meet ICAO recommendations with aircraft with an application for new type certification on or after 1 January 2023 needing to recover the aircraft flight data in a timely way. “There are two options here, a deployable flight data recorder or a means to transmit flight data recorder data via reliable and truly global satellite networks such as Iridium or other reliable truly global communication systems,” says Stepin. “The users who benefits most out of this are the aircraft accident investigation authorities and the various supporting aircraft location search assets. No longer will flight data recorder be lost, but also no longer will it take weeks or months to find and retract data for investigation purposes, saving in millions and in some case hundreds of millions of dollars which is utilized to search and retrieve aircraft flight data.”