AF 447 Search to resume

[Jox]

CJ,

The customer required options or the system that I was involved in evaluating were many and comprehensive but to try and provide an answer to your question "is there any real perceived requirement for transmission of these huge volumes of data in real time” depends on what you seek to achieve from it.

How many commercial incidents and losses result in not being able to locate the two critical boxes or having done so, they contain no useable data? Answer – very few. How much money is required to be spent in an attempt to discover the whereabouts of the lost devices to provide analysis and information that may determine the cause of an accident or incident thus preventing its reoccurrence? Answer – a significant amount.

Now there are those who will tell you that no amount of money is prohibitive if it will save a single life, I tend to agree with the statement myself but then I am not running an aviation business. The commercial arm of aviation would certainly not agree, they aspire to agree but must make their financial decisions based on what they can afford to spend whilst remaining in business.

The system I have seen operates and records onto its own internal recorder just like a QAR which tends to record fewer parameters than the FDR. It can download the data by several means and not necessarily only whilst in the air via satellite. The data may be downloaded either live (nobody ever suggested that this would be the preferred constant option), at the demand of maintenance control for their purposes or at the initiation of the crew.

Historically aviation accidents are not caused by a single factor or generally a catastrophic failure of a single component. There are usually several factors all working together which culminate in a loss. One of the most common near misses with high workloads is that someone forgets to fly the airplane whilst they are working the problem. I defy any pilot to be able to say hand on heart he has not overlooked or missed something when the work rate to resolve an issue becomes intense.

This system provided an additional option that maintenance control could talk in real time to the pilots, get real time technical data from the aircraft and then engineering could work the problem, the pilots could fly the aircraft and then between them the issue can be resolved.

It is an interesting concept and has merit, if you need not download the data then you save the cost of not doing so. If you have an issue on board and the flight manual states “initiate download” then at least what is happening and being seen now is on its way back to maintrol. If the ship is lost at least they have something whilst they wait for the FDR and CVR to provide the whole picture.

Your second question “how likely is it that after an event/upset the real-time data link to the satellite will remain fully intact until the final second?” Answer I do not know, but if you still have power, your link is connected and you are downloading then your odds are improving all the time. I would rather have some chance than no chance.

Technology improves all the time, after a major event or upset how often does the radio link remain operable until the final second, one for Sallyanne 1234 I suspect.

Jox