Russian jets crash within minutes of each other

Kyle Boatright wrote:
What fuel problem would cause a jet to go down *right now*?

TWA800

Gimli Glider? It glided for 10-15 minutes before landing, and a Soviet
airliner probably wouldn't do much worse..

There was a Gimli glider style landing performed by Tupolev Tu-204 (757 lookalike)
performed at night in Siberia after running out of fuel on the way to an alternate.
They were lucky to be flying a latest Tupolev, since the older Tu-154
(one of the involved in yesterday's crash) have no RATs and their hydraulic system
is completely dependent on the engines running (there are three of them plus APU after
all), once they flame out, the -154 becomes uncontrollable and enters agriculture.
Tu-134 on the other hand is old enough not to posesses hydraulic controls at all,
other than a yaw damper, so this shortcoming becomes an advantage in such case.

--
HECTOP
PP-ASEL-IA
http://www.maxho.com
maxho_at_maxho.com

On Wed, 25 Aug 2004 at 20:51:11 in message
, Kyle Boatright
wrote:

What fuel problem would cause a jet to go down *right now*? Airliners glide
decently and a crew with even a little training would get off a mayday call
and try and work the situation in the time it would take a flamed-out
airliner to go down. A back of the envelope figure is that an airliner
probably has a sink rate of 2500 fpm or less in glider mode... Remember the
Gimli Glider? It glided for 10-15 minutes before landing, and a Soviet
airliner probably wouldn't do much worse...

More recently wasn't there an Airbus (I forget which type) that lost
fuel over the Atlantic and glided some 70 nm(?) to the Azores and had
enough height left for a circuit before landing? Modern airliners are
efficient partly because they have very good Lift/Drag ratios.

I agree that the sink rate is around 2000 ft/min or so but it is
Lift/drag that gives you the distance. I guess that airliners cruise
around 250 knots IAS and that that is near the optimum Lift/Drag ratio
point.
--
David CL Francis

"David CL Francis" wrote in message
...
On Wed, 25 Aug 2004 at 20:51:11 in message
, Kyle Boatright
wrote:

What fuel problem would cause a jet to go down *right now*? Airliners
glide
decently and a crew with even a little training would get off a mayday
call
and try and work the situation in the time it would take a flamed-out
airliner to go down. A back of the envelope figure is that an airliner
probably has a sink rate of 2500 fpm or less in glider mode... Remember
the
Gimli Glider? It glided for 10-15 minutes before landing, and a Soviet
airliner probably wouldn't do much worse...

More recently wasn't there an Airbus (I forget which type) that lost
fuel over the Atlantic and glided some 70 nm(?) to the Azores and had
enough height left for a circuit before landing? Modern airliners are
efficient partly because they have very good Lift/Drag ratios.

I agree that the sink rate is around 2000 ft/min or so but it is
Lift/drag that gives you the distance. I guess that airliners cruise
around 250 knots IAS and that that is near the optimum Lift/Drag ratio
point.
--
David CL Francis

David,

Agree with your L/D vs glide range comment. My point went to the idea that
an airliner's sink rate is low enough that even with a complete flame out
(unless the airplane was already at very low altitude), there should be
plenty of time to get off a Mayday call and possibly relate the basics of
the problem to a controller.

KB

On Thu, 26 Aug 2004 at 22:02:30 in message
, Kyle Boatright
wrote:

Agree with your L/D vs glide range comment. My point went to the idea that
an airliner's sink rate is low enough that even with a complete flame out
(unless the airplane was already at very low altitude), there should be
plenty of time to get off a Mayday call and possibly relate the basics of
the problem to a controller.

In Macarthur Job's book where he describes the events when the BA 747
lost all 4 engines near Java he says that with all engines stopped at
37,000 feet the aircraft should take 23 minutes to sea level.

That certainly reinforces your point! It also suggests a 1600 ft/minute
descent rate. If the speed was 250k then, if I am right, it also implies
a glide L/D of around 15.

Airliners are _not_ bricks! :-)
--
David CL Francis

"James M. Knox" wrote:

Fuel problem???

No. The BBC reported yesterday that an explosion was seen on one of the aircraft
before it went down and that the other plane sent indications of being hijacked (I
assume something like a transponder code) shortly before disappearing.

The report continued that any sort of mechanical problem would almost certainly have
allowed the flight crew time to radio a message.

George Patterson
If you want to know God's opinion of money, just look at the people
he gives it to.

"G.R. Patterson III" wrote in message
...


"James M. Knox" wrote:

Fuel problem???

No. The BBC reported yesterday that an explosion was seen on one of the
aircraft
before it went down and that the other plane sent indications of being
hijacked (I
assume something like a transponder code) shortly before disappearing.


The reporter I just heard on the news here said someone hit the SOS button
before the plane dropped off radar.

Allen

"Allen" wrote in message
m...

The reporter I just heard on the news here said someone hit the SOS button
before the plane dropped off radar.

Hmmm. Exactly which button would that be?

I guess all Russian airliners must have a big, red button in the middle of
the panel marked "SOS" (or maybe it's the little plastic gag "panic button"
that Sporty's sells?).

Sounds like a reliable report to me.


--
David Herman
N6170T 1965 Cessna 150E
Boeing Field (BFI), Seattle, WA
- - - - - - - - - - - - - - - - - - - - - - - - - -
Visit the Pacific Northwest Flying Forum:
http://www.smartgroups.com/groups/pnwflying