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meggriffin
16th Apr 2010, 21:09
Hi Guys,

Just wondering about what special procedures your company has implemented in the current situation?
I'll start with my company: NONE!!

lomapaseo
16th Apr 2010, 21:22
Just wondering about what special procedures your company has implemented in the current situation?
I'll start with my company: NONE!!

I would be happy if no special procedures were implemented as the industry has known for years how to deal with this in the cockpit at least from the big iron.

We've had several worldwide conferences on this and with broad representation and the major Airplane and engine manufacturers have all bought into the wording.

GSLOC
16th Apr 2010, 21:25
Thottle levers: idle;
Conduct emergency descent in accordance with QRH (below base of the cloud, but not below MORA/GRID-MORA) and visually maneuver away from ash cloud.

DBate
16th Apr 2010, 22:25
There is a special procedure in our company in case of volcanic ash encounter. The first actions to be taken are memory actions, and must be known by heart:

Escape Maneuver - INITIATED
Auto Throttle - DISENGAGED
Throttles - IDLE
Descent - INITIATED
ENG IGN OVRD Sw - OVRD ON
ANTI-ICE Sws - ALL ON
Pack Sws - CHECKED ALL ON
ECON Sw - OFF

So the basic aim is to get out of the ash cloud ASAP. General recommendation is a 180 turn, as you cannot be shure how far the cloud extends in front of you.

The descent is of course to keep the engines at, or as close to idle as possible, and thus keep the temperature within the engine as low as possible to keep any glass particles contained in the volcanic ash from melting and then solidifying in a cooler part within the engine. Glass particles in volcanic ash usually have a melting temperature of around 600-800C, while the christalline parts usually melt at around 1100-1200C. The effect of molten particles on the engine is much more severe than just the contamination with particle dust.
At times it might be a good idea to shut down one or two engines until you have left the ash cloud - but I hope never to be in a situation that asks for something like this.

Finally, switching on all available bleed sources is said to increase the stall margin of the engines.

Hope we all never have to use a procedure like this one.

Regards,
DBate

Neupielot
20th Apr 2010, 03:02
1 procedure= Avoid at all cost. :ok:

Dan Winterland
20th Apr 2010, 05:06
The modern types I have flown from Airbus and Boeing all have VA procedures published. If your company dosn't then I suggest you speak to your management to get some instigated ASAP.