"Dave" wrote in message
...
dennis@home wrote:


"Dave" wrote in message
...
Steve Walker wrote:
On Mon, 19 Apr 2010 16:32:48 +0100, Dave wrote:

Nightjar "cpb"@ insertmysurnamehere wrote:
Chris J Dixon wrote:
"Nightjar \"cpb\"@" "insertmysurnamehere wrote:

It was not a fall, but a deliberate fast descent to a level where
oxygen was not needed - one of the crew's oxygen masks was broken -
and where engine restart procedures might be expected to work,
which they did.

It's a pretty steep glide angle isn't it? I reckon it would feel
close enough to a fall for the passengers
The glide angle is 15:1, but he had to go down a lot faster than that
because of the oxygen mask problem.
The angle of attack would also be beneficial to re staring the engines
as well, by using the ram air to turn the compressor fan blades

Dave

Apparently they had to keep varying their angle, as the engines require
a
specific range of airspeed to re-ignite,

I never went into this in any depth, so I have to accept what you say,
but I have my doubts. I dabbled in spin trials many years ago, but
didn't get to meet the aircrew till many years later to ask them.

but they'd lost their airspeed
indication.

I can't see that happening. There is a pitot static system on aircraft
that doesn't require power.
Pitot reads the air speed from probes that point forward and this air is
transferred to a simple gauge that measures and displays the speed.
Usually duplicated so that the co pilot gets a reading from a separate
probe from the pilots source.

The probes fill up with ash.

I very much doubt it, as there is no air flow through them. Because of
this, the ash would flow around them. We never encountered this problem
with any aircraft supplied to Saudi Arabia.

Which volcano eruptions have these Saudi jets been flying through?


the same happens with the engine sensors and various other bits.

The engine sensors are only interested in the air temp into the engine.
There are no other bits.


fuel flow, air flow, temps, pressures and lots of things.
There are lots of bits affected by ash, the turbine blades are one of them.

Dave