Ash clouds threaten air traffic

[Cubs2jets]

Stagger posted this back around post #1172:

ETOPS implications
It's not simply engine failures during volcanic ash exposure that needs to be considered.

Is it not possible that a period of significant ash exposure may have implications for engine in-flight shutdown (IFSD) rates in the weeks and months to come? Is it safe to assume that engines that have spent significant time operating in ash environments will have the same IFSD rates as those that have not?

ETOPS certification depends on statistical assumptions based on IFSD rates. If ash exposure leads to changes in IFSD rates then these assumptions may no longer be valid. The fact that both engines on an airframe will likely share the same recent history of ash exposure is also relevant.

I fear it was lost in the "rush" to post about test flights and some departures. I think this is a SIGNIFICANT point that has been made and pushed aside by the incrediably fast pace of this thread.

If the implications are true and some airlines loose their ETOPS certification they may well find their aircraft having to route further north over the Atlantic and closer to the source of the problem - potentially further exacerbating the situation. There are other scheduling implications to loosing ETOPS capability too.

The present situation IS unprecedented and there is no guidence as to what ash PPM is reasonably acceptable - short term AND long term. The collective governments, OEM's and airlines should collaborate on flight testing of flights in the various densitys of ash and the deleterious effects on jet engines and other aircraft (flight instrument) systems.

It will be interesting too to see how the insurance companies deal with claims of damage from volcanic ash from THIS episode.

C2j