ETOPS anyone? 4 engines better.....
Airbus girl, on a previous post, invites us to consult Boeing's advice with regard to meeting volcanic contributions to the atmosphere.
Boeing says "Flight crew should note that airborne weather radar is INEFFECTIVE for distinguishing ash and small dust particles.
"If you do fly into volcanic ash, the engines may respond by surging, torching from the tailpipe, and flameouts can occur...."
"If ash fouls the pitot tube, the IAS can decrease or fluctuate erratically...."
So Boeing recommends, if finding oneself in a volcanic ash cloud, the following steps:
1) Reduce thrust
2) Turn off auto throttle
3) Exit, with 180 degree DESCENDING turn
4) Turn on anti- ice systems
5) Start the APU for systems power
6) Crew Oxygen may be needed
7) Try to start the engines
8) Monitor EGT
9) Fly by a/s and pitch attitude.
There you go boys, now you know what to do....
However, as a previous poster has pointed out, the permission for 777 and 767 to fly across vast ocean spaces with 2 engines is relying on past experience of hardly ever having 2 donkeys stop breathing at once.......
Other posters have warned that the gradual failure over time of a jet engine may be greatly accelerated with volcanic glass ingestion, one vulcanologist has compared the action of an Icelandic volcano blasting off under a glacier to pouring water on a chip pan fire, this being one of the reasons not all volcano dust is the same.
If the airlines and the pilots and the pax are just too antsy to wait for the upper winds to change, perhaps would it be wise to stick to 4 engines, two of which are changed after relatively short exposure to interesting conditions, and the other two run for longer.....