Tracing The Future

Steve Winter examines what issues UN aviation agency ICAO faced in assessing global tracking technologies following the loss of Malaysia Airlines Flight 370
In response to the disappearance of Malaysia Airlines Flight 370 on March 8, the International Civil Aviation Organization (ICAO) held a two-day multidisciplinary meeting at its headquarters in Montreal on 12-13 May, to address the issue of whether there should be a capability to track civilian flights worldwide and what technologies might be made available to enable it.
More than 200 delegates from over 50 countries and international organisations attended the meeting. A number of organisations, including Inmarsat and Iridium, proposed technical solutions. In summary, the meeting made a number of recommendations, including: in the near term, global tracking should be pursued as a priority and that a concept of operations be developed; that near-term needs should be addressed by an Aircraft Tracking Task Force (ATTF) coordinated by the International Air Transport Association (IATA)
In the medium term, performance-based standards should be developed and improvements to Emergency Locator Transmitter technologies (ELTs) investigated while in the long-term, requirements for streaming of in-flight data should be developed in conjunction with the International Telecommunication Union (ITU).
This article reviews the technology proposals in light of a number of criteria relevant to avoiding similar incidents to the disappearance of Malaysia Airlines Flight 370 and Air France Flight 447 in 2009.
Different Circumstances
The circumstances of the disappearances of AF447 and MH370 are somewhat different, which has some significance from the perspective of global tracking needs.
AF447 was in a remote oceanic area, with only ACARS satellite communications, when it disappeared. MH370, in contrast, was within radar and ADS-B coverage when communication with the aircraft was lost.
The disappearance of AF447 was not detected for some time, whereas that of MH370 was noted almost immediately after it disappeared from radar coverage and failed to make voice contact with Ho Chi Minh Centre although it took a number of hours to realise the significance.
The disappearance of AF447 and its crash were directly related and near-coincident; MH370 -based on the currently-available evidence – flew for many hours before crashing, presumably after running out of fuel.
AF447 was lost as a result of a combination of technical problems and the crew’s response to them – there has been no suggestion of malicious intent. In the case of MH370, it is suspected that the aircraft’s transponder and ACARS were intentionally disabled, although this may only be confirmed by the eventual examination of any wreckage found.
AF447 ACARS was streaming aircraft performance information in near-real-time over ACARS to Air France’s operational centre; MH370 was only providing limited periodic ACARS information, and this was last received several minutes before the aircraft disappeared from radar.
Most importantly, in terms of locating any wreckage, in neither case, did the Emergency Locator Transmitters (ELTs) appear to trigger. This was presumably because of rapid submergence of the aircraft following surface impact.
Why Global Tracking?
There are several distinct gaps in tracking capability, shown in the table below, that improved tracking could have helped address in the two disappearances.sw1While it is clear that closing any of these gaps would not have prevented the loss of AF447, it is possible that some of them could have improved the response for MH370. Indeed, they could have led to quicker SAR and recovery responses, including additional time to localise the flight recorders’ acoustic transmitters before their batteries ran down.
Technology Options
A number of global tracking technology options were presented to the ICAO meeting, as summarised in the table below. Note: Rockwell Collins and the ITU also presented information, but neither of them offered specific tracking solutions.
C2As can readily be seen from the table, no single solution provides all the needed capabilities, and only the COSPAS-SARSAT one meets the ELT-related requirements. The space-based ADS-B solutions offer the advantage of greater coverage than ADS-C, both through a higher equipage rate (quoted at in excess of 90 per cent) and expanded polar coverage of the Iridium constellation. However, these are not currently available: Aireon’s solution, for example, is not expected to be fully operational until 2017.
The European Union also provided a very informative paper (WP/6) to the meeting. The paper discussed previous work performed under the SESAR OPTIMI project (Oceanic Position Tracking Improvement and Monitoring Initiative) technical options, and includes a set of proposed performance criteria and assessment of technical options against them. Criteria include:

  • Degree of global coverage
  • Robustness to power outages
  • Robustness to intentional disconnection
  • Geographical accuracy
  • Timeliness of alert
  • Pros and cons, such as current availability and time/cost for development.

The EU paper does not draw specific conclusions as to which solutions are to be preferred.
The information presented to the ICAO meeting demonstrates that there may be significant benefits to improving global tracking capabilities. However, many of the proposed solutions, e.g., improved ELTs, will take many years to develop and introduce into service.
Therefore, in line with the meeting’s overall recommendations, the author sees a multi-phased approach as being most promising:

  • In the near-term, exploit and extend the capabilities of the current Inmarsat/ADS-C-based system to provide higher-frequency reporting for FANS-equipped aircraft and augmented information for those aircraft that aren’t (i.e., that only support the “handshake”);
  • In the medium-term, look at deploying space-based ADS-B solutions to provide more-accurate global coverage from the Iridium constellation, as well as looking at improving ADS-C systems to provide enhanced alert triggering;
  • In the long-term, look at improving ELTs to provide a deployable capability, together with remote, on-demand activation of ELTs. In addition, real-time streaming of critical flight data should be investigated further with a view to deploying solutions.

While affordability does not appear to have been explicitly addressed by the meeting, it would appear that this is not a major concern for some, at least, of the proposed solutions. For instance, it should be noted that the Inmarsat proposal was for a “free” service, and Aireon stated that their space-based ADS-B system is “fully funded” and should be interoperable with current ADS-B transmitters.
The ICAO meeting called for delivery of a final high-level concept of operations for global tracking to the High Level Safety Conference (HLSC 2015) in February next year, at which point we should be able to see what progress ICAO and the aviation community are making in this important area. Let’s hope we see some real improvement.
Steve Winter in an independent aviation consultant