Jefferson City pilots took plane to maximum altitude

wrote in message
oups.com...
The reason these engines failed is MORE COMPLICATED than the fact they
were at 41,000'. These planes can fly at 41,000'. What happened is
related to how they got to 41,000'. They got there by exceeding the
maximum climb rate.

Interesting theory. Please share with us where you obtained that
information.

Your theory seems the most plausible of anything I've heard, but the NTSB
hasn't released the final report, nor have I seen any specific information
about the climb they executed. Do you actually have a reference for your
statement, or are you just guessing?

Pete

Well, the idea behind this theory is this. Engines burn fuel. Fuel
causes heat. Heat needs to be dissipated into the air (air btw, is the
only place it can ultimately go). As you climb there is less air. Heat
that was made with the more dense air some time ago needs to be
dissipated by less dense air now. Less dense air cannot dissipate as
much heat. Get the picture? We see steady state example of this in
overheating turbocharged piston engines that can be pushed too hard at
altitude. This climbing one is a little more complicated because it
involves changing air density, but same basic idea. The heat collects
in the engine. The cooling is designed for air density only so much
less than the air density that made the heat. Exceed that and you
overheat. The overheated engines seized. Climb at the rate the engine
is designed for and this wont happen. Could only climb that fast
because they were empty.

It's just a theory so far as what CAUSED the accident, but this
behavior is well known.

Heat that was made with the
more dense air some time ago needs to be
dissipated by less dense air now. [...]

The cooling is designed for air density only so much
less than the air density that made the heat.

I didn't realize that heat remembered how it was made.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain."
(chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

wrote:

One word of advice. Don't get your accurate information from the
newspapers. You have to go deeper to get accurate information.

....like say, from usenet. ;-)

"Doug" wrote
It's just a theory so far as what CAUSED the accident, but this
behavior is well known.

From my initial training in jet powered aircraft (T-2V) in 1959
during Navy flight training to my retirement from flying jet
powered aircraft (B-727) at PanAn in 1991, I have never heard
of this theory nor experienced its effects. And, I can assure
you that the small B-720 with the big B-707 engines when empty
climbed like a rocket to 41,000'.

Sure sounds to me like a simple case of not enough fuel pressure
from the tanks to feed the engine driven pumps. This could be
caused by various reasons from failure to use the tank mounted
boost system to operating below the fuel freeze point allowing the
fuel filters to become obstructed.

A couple of web sites with items of interest:

http://www.tfec6.org/Download/invited/JKLee.pdf

http://www.geocities.com/fchemical/1.html
At extremely low temperature a fuel may have a high viscosity.
Although a boosted pump is use to deliver fuel to the engine,
the oil feed to this pump from the oil tank is by gravity and
it is essential that it should not be impeded by too high viscosity
fuel with final boiling points below 300oC generally have
viscosities sufficiently low for them to flow to the pump its
temperatures down to their freezing point. The limiting temperature
of use would be determine by solidification of the fuel in the tanks,
and this would not occur until well below the freezing point, firstly,
because the freezing point is the temperature at which solid being to
separate under arbitrary test conditions and not the temperature at
which the fuel solidifies and secondly because of mechanical agitation
inherent in the system. In practice therefore the specification of a
maximum freezing point corresponding to the lowest service temperature.
Likely to be experienced provides an ample margin of safety. A maximum
freezing point of -40oC or -60oC, according to the type of the service,
ensures adequate flow under all practical conditions including starting
at very low temperatures.

I'm putting my money on wrong fuel (freeze point) for the existing OAT.

Bob Moore
ATP B-707 B-727 B-720
PanAm (retired)

What kind of engines did the aircraft on the Jefferson City flight
have? What kind of engines are on the Boeings that Bob flew?

"Doug" wrote
What kind of engines did the aircraft on the Jefferson City flight
have? What kind of engines are on the Boeings that Bob flew?

What kind of experience/training do you have?

Bob Moore

John Galban wrote:

Bucky wrote:

For example, the top speed of a car could be 120 mph, but it would be
dangerous to drive it at that speed because a sudden movement in the
steering wheel could cause the car to flip over.


This can happen at 75 mph or at 50 mph. What's so magic about 120
mph? If you're point is that driving a car is dangerous, I agree. If
you're trying to make some analogous connection to flying a plane at
it's service ceiling, you missed the boat (car, plane...).

John Galban=====N4BQ (PA28-180)

Little notice from a German "Autobahn" driver:
I had a Alfa Romeo where I felt very comfortable even with 150 mph
and I had a Jaguar where 120mph was nice but at 150mph I had the
impression to became instable.
I pushed a Chevy Blazer to 100 mph and was afraid to kill myself.
Everything is relative , some dudes manage to flip over at 30mph , I
have seen this last December here in Dallas, and with the right car and
environment even 200 mph are safe.

Sorry way OT.

Engine out issues aside, one thing that struck me about this accident
was the fact that these guys had so much altitude in which to glide to
a safe landing that I wonder if it was actually _too_ much altitude? I
don't know how far away the airport was that they finally decided upon
for the emergency landing attempt, but clearly they didn't succeed in
meeting their goal. Were they too complacent in thinking they'd be able
to restart the engines, given that they were nearly 8 miles up?

One of the things I always try to get on a long x-country in a 172SP is
altitude. I've only flown on the east coast of the U.S. during my short
3 years as a private pilot, and while there are lots of airports
around, there are stretches where I'd be out of gliding range from an
airport even at 10,000 feet. These guys had 4 times that, and still
couldn't make it to an airport. Was there a field that was closer and
still suitable enough for their plane to land on? Considering they were
in a no-power situation, I assume on short final they'd be coming in
pretty close to stall speed to minimize forward velocity when touching
down (tho maybe I'm wrong on that point). I just can't believe that
with all that altitude they couldn't get safely on the ground.

--
Guy

wrote in message
oups.com...
The reason these engines failed is MORE COMPLICATED than the fact they
were at 41,000'. These planes can fly at 41,000'. What happened is
related to how they got to 41,000'. They got there by exceeding the
maximum climb rate. The plane was empty so it climbed very fast. But
due to some complicated factors, the engines cannot go to that altitude
that fast. They overheated. This was a published limitation. They
exceeded it. Even my simple explanation is not adquate as it is more
complicated than this. This is due to the fact that I don't completely
understand it either.

And to answer your question, yes it is safe to operate at max altitude,
if the pilot follows all of the correct procedures when operating the
plane and if the plane does not have damage and has been maintained
correctly etc. The plane has been tested there, and higher still, so
there is some safety factor.

These engine failures were from some complicating factors. Not just as
simple as flying too high.


Where do you come up with this BS? There is no relationship between climb
rate and over temping.

Mike
MU-2