Could real-time tracking of flight MH370 have been helpful
The Malaysian government released a five-page document last week detailing some of the efforts made to locate the missing plane over a large area, including expanding the search to include the Southern Indian Ocean.
The search for the wreckage of Air France’s 447 Airbus that disappeared in the Atlantic Ocean between Brazil and Africa took two years.
In the past five years, there have been two instances where large commercial aircraft that transport passengers and cargo have disappeared without their exact location being known.
In the report, the Malaysian Air Accident Investigation Bureau suggests that the International Civil Aviation Organisation ICAO examine the safety benefits of real time tracking of all transport planes.
This would require a way to track aircraft when they are not within the radar coverage.
As it would be impossible to cover all oceans with surface radar, satellite monitoring would have to be used to track aircraft mid-ocean.
GPS can’t help?
This technology cannot be used because it is not compatible with the GPS (Global Positioning Satellite) technology that is used in smartphones or car navigation systems.
GPS works only one way. Flickr/Highways Agency, CC BY
This technology uses only one-way signals from the GPS satellite constellation that are received by the telephone. The phone can determine its location geographically with great accuracy, but the GPS has no information about the actual location of your phone.
In order for real-time location technologies to work, there must be two-way communications to let the system know where the receiver is.
The simplest and most cost-effective way to do this is for every aircraft to periodically “ping” satellites, say, once per minute, with information including the aircraft’s latitude and longitude.
It would be best to have continuous communication in order to determine the exact location of any possible crash site. However, this would be cost-prohibitive. Once or twice a minute would suffice without affecting the knowledge of the aircraft’s location too much.
A real-time tracking system will also require the launch of additional satellites in order to provide global coverage. The costs associated with implementation are, therefore, not insignificant.
Existing technologies
The majority of modern passenger transport aircraft are already capable of transmitting data via satellite to the ground, even though the communication isn’t continuous.
The Aircraft Communications Addressing and Reporting System ( ACARS ) allows for technical data from aircraft, such as engine performance information, to be sent automatically back to the airline. The airline sends operational information to pilots, such as flight information and advisories.
Flight MH370 had ACARS. The Malaysian report states that even though the ACARS may have been deactivated during the flight, it was still “logged onto the network.” The system was periodically pinging satellites throughout the flight.
The Inmarsat Analysis was based on the Doppler Effect of six of these signals, which showed that the aircraft may have flown southwest toward the Southern Indian Ocean.
Why not transmit black box data
When developing and implementing real-time tracking, it is important to consider the routine transmission of flight recorder key parameters.
Australian inventor David Warren, with an early prototype of his black box flight recorder. DTSO
The cost and bandwidth of modern digital flight recorders may be an obstacle to transmitting the full information.
In cases like MH370, the transmission and storage of important flight data, such as altitude and airspeed, heading and engine power remaining, as well as vertical, lateral, and longitudinal acceleration, flight control, and flap positions, would be extremely useful.
It would be necessary to find the wreckage for moral and humane reasons. Theoretically, the less need there is to recover flight recorders, the more data that can be transmitted and stored remotely.
It would also be possible to start a comprehensive investigation of the crash even before locating the crash site.
Flight crew associations around the world will raise concerns about confidentiality and misuse of data, particularly if the data includes audio files that are compressed and encrypted from cockpit voice recording data.
Safety improvements
As the search for MH370 proceeds without finding any evidence of the actual wreckage and as the associated costs increase, there is no doubt that changes will be made to air safety.
There is already a proposal to increase the recording time for cockpit voice recorders from 2 hours to 20 hours.
Globally, governments will continue to place more emphasis on finding alternative ways of tracking aircraft and establishing systems of routine transmission and storage of flight information.