Flight data recorders, also known as FDR’s or ‘Black boxes’, are fitted to most large modern aircraft and are mandatory on airliners. Heavily protected in case of accident, they record up to 88 flight parameters, such as speed, flight patterns and position, and data related to the plane’s various systems including computers, hydraulics, engines and flaps.
The Canadian company AeroMechanical Services
Ltd has been testing a new FDR that looks so promising that it is scheduled to begin in-flight service testing in the next few weeks.
In current versions of FDR’s, data is recorded and stored in real time, but is not transmitted to the ground. This means that the data they contain can only be accessed and analysed when the plane lands or crashes.
The AF447 disaster and its inconclusive aftermath have once again highlighted how crucial the FDR’s contents are in analysing the cause of accidents. The plane crashed into the Atlantic in an area where the ocean’s depth is around 6000 meters. That meant that the FDR’s have not been found. If that remains the case the causes of that accident may never be known.
There have been several instances of FDR’s never being found and many others where they were so badly damaged that the data they contained was wholly or partially unusable, considerably reducing the chances of finding out why the accident happened.
That’s where data-stream FDR’s, also known as ‘Smart Boxes’ or ‘Live Boxes’ come in. They send all their data to the ground in real-time, so even in the event of an accident all the data sent by the plane is received up to the moment the plane crashes or the FDR’s are disabled for another reason.
Any investigation into an accident could instantly begin analysing the data sent. That would considerably reduce the time taken to identify the causes of an accident and that would mean that airlines and the aviation industry would be able to react more quickly in order to take the necessary steps to avoid similar accidents in the future.
If a data-stream FDR had been in use on AF447 when it crashed, all the data sent by the plane would have been received up to the moment the plane hit the water or it could not transmit for another reason. That would have made the search for the FDR’s unnecessary, and French aviation authorities would most likely already know exactly what caused the crash.
Both airlines and pilots have called for them to be developed but the technical problems involving the transmission of so much data at once have proved to be insurmountable up until recently.
The system is called AFIRS, for Automated Flight Information Reporting System, and it will be tested for an unnamed client. 30 airlines are said to have placed orders for it in the event of the tests being successful.
The main challenge faced by developers has been to find a way of sending large amounts, or ‘packets,’ of data in real-time and from every corner of the globe. Current satellite systems cannot handle that much information at once.
AFIRS uses Iridium satellite communications, which have the advantage of covering every part of the globe. They too can only handle a limited bandwidth, thus they cannot handle large amounts of data, but AFIRS contains new data compression technology designed to reduce the size of data packets and fit them into the available bandwidth
This is the system which is being tested.
The system also includes a two-way voice capability, which means that routine as well as emergency in-flight problems can be discussed and analysed in real-time in order that the crew make the right decisions to maintain the plane’s safety.
Airlines all over the world will be following and analysing the results of the tests on the AFIRS system closely.
If those tests are successful, the nature of the technology used in Flight Data Recorders is likely to change almost overnight and searches for them in the event of accidents may one day become a thing of the past.