Jet engine sim for testing 9/11 planes

Originally posted by ULTIMA1
Didn't i post a report about black boxes being switched before ?

I must have missed the report you posted that proves the black boxes from AA77 were switched and that's most likely due to the non-existance of such a report. I hope you noted what I said about the chain of custody that was maintained for such a vital piece of evidence and the NTSB has signed for its authenticity. You'll need some mighty good evidence to justify accusing NTSB of tampering with evidence and unless such evidence exists, this remains as positive evidence of AA77 having been destroyed by impacting the Pentagon.

Back closer to the original topic of jets disturbing the air and particularly the blast from the jet engines felt by occupants of vehicles when AA77 passed over head at an altitude of about 20' (~6m):

The plane had a -ve pitch of 5 degrees (nose down) so for any jet blast to reach the ground at that point, the dispersion angle of the blast has to exceed 5 degrees around the centreline otherwise it only reaches the ground when the plane hits the ground. So I'll allow for the dispersion to be 10 degrees which gives me a distance of some 35m past the cars before the blast actually hits the ground and at that distance, the even 10 degree spreading results in a diameter of the blast cone of 14m and a csa of about 154m^2 which compared to the diameter of the engine of approx 2m (3m^2) indicates the power of the blast will be approx 1/50th of what it is immediately behind the engine IE some 2%.

Also, at the point where the plane crosses the road at 6m altitude, the blast would be felt some 70m behind the plane, therefore hardly more than a gentle breeze using the same calculation as above.

Is there any better information I could use to refine this estimate?

Originally posted by C0bzz
Pilots almost always know every little TINCY bit about there aircraft, in and out. Otherwise, if they have a problem, they're good as dead.

Well i have asked pilots questions and they could not answer some.

Originally posted by weedwhacker
[If you wish to ask me a specific question about a B757 or B767, go ahead.

Well other pilots could not answer this question or had a hard time with it.

Name a system on the 757 or 767 is pneudraulic?

Originally posted by ULTIMA1

Originally posted by C0bzz
Pilots almost always know every little TINCY bit about there aircraft, in and out. Otherwise, if they have a problem, they're good as dead.

Well i have asked pilots questions and they could not answer some.

Dude!!! I just asked you to ask me!!!

You say you have asked pilots....????

I offered to answer.....please, ask away!!!!

Oh....and, please don't ask about the Phantom, the 'F-4'.

I didn't fly that airplane. Care to ask me about the B757/767?? Then, I can answer.

reply to post by ULTIMA1



Does it make any sense at all to give a remote pop quiz over the internet in the day of Google?

Everybody...let's all Google "pneudraulic" and answer Ultima's question. You might even get your information from the same web page he did!

Originally posted by ULTIMA1
Well other pilots could not answer this question or had a hard time with it.

Name a system on the 757 or 767 is pneudraulic?

It looks like you're derailing your own thread.

Any comments on my posts related to jet blast and turbulence that could be expected to be felt at ground level from a plane passing overhead?

Originally posted by weedwhacker
I offered to answer.....please, ask away!!!!

I guess you missed the question i posted.

Name a system on the 757 or 767 is pneudraulic?


[edit on 29-5-2008 by ULTIMA1]

reply to post by ULTIMA1


EDP, hydraulic motors, A/C motor pumps, servo valves, scavenge pumps, boost pumps, lube pumps, cylinders, accumulators, PTUs, starters, turbines, fans, ATMs, ACMs, ADTMPs, PDUs, PDAs, IDGs, CSDs, generators, rotary actuators, linear actuators, T.R. actuators, servo actuators, fuel controls, jackscrews, transmissions, gearboxes.

Originally posted by HLR53K
[EDP, hydraulic motors, A/C motor pumps, servo valves, scavenge pumps, boost pumps, lube pumps, cylinders, accumulators, PTUs, starters, turbines, fans, ATMs, ACMs, ADTMPs, PDUs, PDAs, IDGs, CSDs, generators, rotary actuators, linear actuators, T.R. actuators, servo actuators, fuel controls, jackscrews, transmissions, gearboxes.

Not really what i was looking for. I was looking for a main system on the plane.

Originally posted by ULTIMA1

Originally posted by weedwhacker
I offered to answer.....please, ask away!!!!

I guess you missed the question i posted.

Name a system on the 757 or 767 is pneudraulic?


[edit on 29-5-2008 by ULTIMA1]

OK...I'll bite!

Let me first, and not as a person who wishes to ridicule, break down the word "pneudraulic"

That is not a word I've ever seen, but to break it down....'pneu' is usually, in airplanes, referring to 'pneumatics'....air pressure systems, in general.

"draulic"....well, I'm not a scientist, but that term refers to the incompressibilty of a liquid.....that's why he have 'hydraulic fluids' in our cars.....to operate our brakes!!!

Back to the question, about this word....."pneudraulic".....

Very interesting word, not one I have ever seen, until now.

The B757/767 has, as an emergency device, something called a 'RAT'....acronym for 'Ram Air Turbine'

This, because, there are no direct cable links, any more in moderns jets. What this means is.....the cables from the control wheel operate hydraulic valves, to thusly operate the control surfaces. There is no DIRECT cable control, to control surfaces! Not anymore, not on modern jets.

On a B757....there are two engines. Each has a generator (for electricty) and a hydraulic pump (for flight controls)

In the VERY rare event that both engines will stop functioning.....I must emphasize this....extremely rare!!!!

There is the RAT....it is built in to the lower fuselage, under the right wing. The RAT will extend, when signalled (and this is an electronic signal, when ground sensing has determined that the airplane is in flight, and that there has been a loss of N1 in both engines, below a certain pre-set parameter, at the same time....thus inferring a dual power loss)

The RAT is spring-loaded, if the door lets it out, per those parameters.

If there is a complete loss of power, then the door opens, and the RAT comes out.....the point here is...it's not FBW, not like Airbus wishes to trumpet! Boeing, at least in the B757/767, still use cable to actuators. BUT, the actuators still need hydraulic fluid to operate.

The engines, when operating, provide the hydraulic pressure, since pumps are attached. If both engines fail, there is insufficient pressure to operate the Flight Controls, unless there is the RAT to provide pressure. That is the concept, and it has been proven to work.

Sorry, an ATS blog is not sufficient to educate you on the complexities of modern jet airplanes.....you will need many more hours of instruction to encompass it all.

Typically, 'ground school' takes at least two weeks.....and, that's surmising you know the subject BEFORE you come into class!!!!

So.....10 days, at about 7 hours per day.....hmmm....my math says....70 hours!!!!!

And I tried to educate you guys, in one post....did my best......

Originally posted by weedwhacker
Very interesting word, not one I have ever seen, until now.

RAT was a nice answer but it is not a main system of the aircraft.

Well i do not know why pilots seem to have a hard time with this.

Its very simple a main system on the 757 or 767 that is pneudraulic is the landing gear struts. They have hydraulic fluid in the bottom portion and high pressure air in the top portion.

The reason you have the combination is so the struts can handle the weight and stresses.

reply to post by ULTIMA1


Heh, ok, odd that I went into more detail and supposedly got the answer wrong.

It's basically any system on the aircraft that uses both hydraulics and pneumatics to activate.

The thrust management system or anything that gets fed off the engines. They run with hydraulic pumps and the RAT run on independent resevoirs powered by pneumatics.

I was going to say the oleo landing gear, but didn't know if you were looking for a system that had both pneumatics and hydraulic, but in independent lines.

They aren't used as much to "handle the stress" as they are to just dampen the shock of landing. If you mean that, then no need to go off in another tangent.

And technically speaking, the landing gear oleo strut itself isn't a "system". It's a component in the landing gear system. But then again, the word "system" is subjective.

[edit on 29-5-2008 by HLR53K]

Originally posted by HLR53K
They aren't used as much to "handle the stress" as they are to just dampen the shock of landing. If you mean that, then no need to go off in another tangent.

Yes, i stated to handle weight and stress.

I would have thought pilots would have thought about the landing gear since it is 1 of the main (simple) systems of the aircraft. I tried to make it simple but you guys were thinking complex systems.

Oh and on jets equiped the arresting gear is pneudraulic also.

reply to post by ULTIMA1


Dude.....I know a little bit about the landing gear struts. I don't have to service them, though....with Nitrogen, to know how they work!!!!

Here's only one part of what a pilot does, on the 'walk-around'

Look at the gear....see at least an inch of strut....then, while looking at the landing gear, make sure the pins that show the brake wear are not 'flush'....since that would indicate the brakes had been diminished, and our stopping ability, in the event of a 'rejected take-off', would be diminished.

We want to see at least 1/8th of an inch, on the brake/wear pins!!!!

Try again, ULTIMA!!!!

Originally posted by ULTIMA1

Yes, i stated to handle weight and stress.

What I was getting at is that even if the landing gear used solid struts (i.e. one piece of metal instead of a piston), it would handle the weight and stress just fine.

Only difference is the giant shock absorbers dissipate the energy of landing slowly instead of feeding it all at once into the airframe.

But we're splitting hairs here.

Originally posted by HLR53K

Heh, ok, odd that I went into more detail and supposedly got the answer wrong.

I noticed that too.

A: "I'm more literate than you. If you're so familiar with the alphabet, name a letter."
B: "H, L, R, K, etc"
A: "Sorry, I was looking for U. Guess you're not as literate as you claim."


It's pure comedy really.

[edit on 29-5-2008 by _Del_]

Originally posted by weedwhacker
Dude.....I know a little bit about the landing gear struts. I don't have to service them, though....with Nitrogen, to know how they work!!!!

Well why didn't you state they were pneudraulic, if you knew?

Here's only one part of what a pilot does, on the 'walk-around'

On the T-38 we had a steel templet to measure the strut to make sure it was ok to fly before the pilot did his walk-around.

Originally posted by HLR53K
But we're splitting hairs here.

Yes, the strut handles weight and stress by acting as a shock absorber.

Originally posted by ULTIMA1

Yes, the strut handles weight and stress by acting as a shock absorber.

Eh, it's what happens when you become a degreed engineer. We like to be as specific as possible about things.

Not saying that your generalization of the landing gear is in any way wrong.

[edit on 29-5-2008 by HLR53K]

Originally posted by ULTIMA1

Originally posted by weedwhacker
Very interesting word, not one I have ever seen, until now.

RAT was a nice answer but it is not a main system of the aircraft.

Well i do not know why pilots seem to have a hard time with this.

Its very simple a main system on the 757 or 767 that is pneudraulic is the landing gear struts. They have hydraulic fluid in the bottom portion and high pressure air in the top portion.

The reason you have the combination is so the struts can handle the weight and stresses.

I apologize, to any and all Mods for pulling this whole quote....ohters have beaten me to it....

'pneudraulic' is indeed, an incredible newly coined word!! Never seen it before, nor shall I expect to see it again, except here at ATS!!

I know the word 'pneumatics', and I know the term 'hydraulics'. Perhaps I just don't know anything about the airplanes I flew for thousands of hours!!

For ULTIMA....you don't seem to have read, earlier....(perhaps I wrote it on another thread) what a RAT is. RAT is an acronym for 'Ram Air Turbine'

RAT is also an acronym for 'Ram Air Temperature'.....but we use many acronyms in aviation. Right now, I am not disussing the temperature probes on a modern jet.....I am talking about the other RAT....

The 'RAT' on the B757/767 is designed to 'pop out' (the deployment solenoid is on the Battery Bus, so even when the generators trip off, in a dual engine failure, the RAT will deploy....it will be released, once a solenoid lets the door open, and it is spring loaded to come out, into the airstream, to use the relative wind to power an hydraulic pump, to make sure the pilots have control authority, while they attempt to get one or more engines restarted. Also, the APU can be started up to 35000 feet. It is designed to provide electrical power for the entire airplane, or pneumatics up to a limited altitude....or both, again, it is a limitation. What do you think we would do in an emergency!!! SCREW the limitations!!!!

Any more questions????