In-Service Airliner Testing

[twistedenginestarter]

When new airliners are launched there seems to be a period of up to a year where post-delivery testing occurs including involving passenger-carrying flights. Can anybody tell me what sorts of things are typically covered and what sorts of special arrangements are made eg extra crew, extra data logging etc?

[ICT_SLB]

Twisted,
I don't know where you get up to a year from - our latest programs didn't allow us that for all the testing. What you're talking about is known as Functional & Reliability ("FNR") testing - generally on the aircraft with the full interior and coupled with customer demos/route proving. A 30 day period seems to be the minimum you can get away with but it depends on the number of new systems you're dealing with.

The aircraft will often just record the main ARINC 429 databusses - you can just take as few as 4 (EICAS, ADC, IRS & GP) and get most of what you need - and, of course with the latest bus types just one ethernet-based bus may very well give you all you need. Remember, too, that the latest EFDRs record more parameters more accurately than most Flight Test prototype aircraft up until the seventies.

This does leave out testing for any new approach system or getting airline certification/crew qualification - this can take more time than the basic cert if the system is "innovative" - the one test program of ours that went way over was when we certified the first CAT IIIA HGS.

[twistedenginestarter]

There's a Flight article I've just mislaid which was referring I think to the A300. Airbus were proudly announcing they could complete this phase in only 9 months. I clearly remember this was occurring when the aircraft was in normal scheduled service. Later I have another article about A320 failures (instrumentation) and Airbus saying there are 'functional adjustments' made over the first 9-12 months of service.