757 stall

[abev107]

Not that anyone here has actually stalled a 757 in real life (I dont think), but was curious if anyone has any knowledge on what the reaction of the a/c would be (maybe someone has done it in a simulator?)

My intention is not to create another conspiracy thread. I am just curious at to how the a/c would perform and if in the heat of the moment the witnesses were unable to accuarately describe what they were seeing.

The following are witness account from Flight93. (The plane that crashed in Shanksville PA on 9-11)

10) An unnamed witness says he hears two loud bangs before watching the plane take a downward turn of nearly 90 degrees. [Cleveland Newschannel 5, 9/11/01]
11) Another unnamed witness sees the plane overhead. It makes a high-pitched, screeching sound. The plane then makes a sharp, 90-degree downward turn and crashes. [Cleveland Newschannel 5, 9/11/01]
12) Tom Fritz, about a quarter-mile from the crash site: He hears a sound that "wasn't quite right" and looks up in the sky. "It dropped all of a sudden, like a stone," going "so fast that you couldn't even make out what color it was." [St. Petersburg Times, 9/12/01]
13) Terry Butler, a few miles north of Lambertsville: "It dropped out of the clouds." The plane rose slightly, trying to gain altitude, then "it just went flip to the right and then straight down." [Pittsburgh Post-Gazette, 9/12/01]


If in fact the a/c did stall, would it be so sharp and so sudden as to almost dive directly into the ground and create a relatively small debris field? According to a private pilot eyewitness, flight93 was in level flight at approx 2,200' (AGL?)

Again, lets keep this to a/c perfromance if we can.

 

[Delta3]

USAir Flight 427

Didn't USAir flight 427 stall when approaching PIT in 1994?

I think the witnesses said that it looked like the 737 just stopped in mid-air and then crashed. The NTSB report would have alot of stuff on the stall.

I always wondered how much airline pilots practice stall recovery, and whether they just do it in the simulator or on a non-revenue flight.

 

[F70pilot]

"I always wondered how much airline pilots practice stall recovery, and whether they just do it in the simulator or on a non-revenue flight."

At every checking event. Only in the simulator.

 

[T-Gates]

Re: USAir Flight 427

Didn't USAir flight 427 stall when approaching PIT in 1994?

I think the witnesses said that it looked like the 737 just stopped in mid-air and then crashed. The NTSB report would have alot of stuff on the stall.

I always wondered how much airline pilots practice stall recovery, and whether they just do it in the simulator or on a non-revenue flight.

USAir 427 was a victim of a faulty rudder PCU which caused a rudder hardover. Read an accient report on it. It sould be required reading for everyone. You can learn alot from it. NOT because there was any sort of pilot error, but you wil learn alot about crossover AOA.....

 

[EagleRJ]

Airline pilots practice stalls at every checking event, but they are usually not aerodynamic stalls. Most airlines have the pilots recover at the first sign of a stall, which is the stall warning or stick shaker. Those are supposed to give you a few knots of warning and prevent an aerodynamic stall, since most airliners have nasty stall characteristics. Next time you're in the sim, disable the pusher and take the plane to the aerodynamic stall. You might be surprised how violent it it.

Part 25 aircraft aren't meant to be stalled. That's why they have the stick shaker and stick pusher. As far as I know, there's no requirement for stall behavior, and most planes- especially those with swept wings- will roll off rapidly at the stall.

 

[profile]

Actually, all of them are brought into full aerodynamic stall during the flight test after heavy maintenance, as well as during initial flight test. Stall characteristics for all the jets that I'm familiar with are very docile, although it can take a bit of altitude to recover if you're really high (above 30k). I know many of the flight test pilots and flight test engineers who have test flown all of the following aircraft and more, and they state the same:A300, B727, MD-10/11, DC-10, 737, 757, 767, 777, 747.

 

[kevdog]

I thought that plane in PA was shot down and covered up by the government. Remeber, it "crashed" right after Cheney ok'd the Air Force to shoot down Hijacked Civilian Airliners. The whole cell-phone thing with the PAX was part of the conspiracy. You have to make the victims "Heroes."

This is at least what my friends in the CIA have told me.

 

[Patriot328]

I've been in the J/S of a 767-300 that's been "stalled". Actually it was stalled to the shaker (WELL into it!), which is before the actual aerodynamic stall, as has already been mentioned. It was in the clean configuration and was pretty violent. I'd imagine a full aerodynamic stall would be a wild ride in a part 25 a/c.

 

[Mogus]

I thought that plane in PA was shot down and covered up by the government. Remeber, it "crashed" right after Cheney ok'd the Air Force to shoot down Hijacked Civilian Airliners. The whole cell-phone thing with the PAX was part of the conspiracy. You have to make the victims "Heroes."

Bill (or is it Bob?) Lear knows it was shot down. He's been on the Art Bell show a couple times and said that. The whole thing does seem a bit shady to me, not that that means anything, of course.

 

[Av8trxx]

Not that anyone here has actually stalled a 757 in real life (I dont think), but was curious if anyone has any knowledge on what the reaction of the a/c would be (maybe someone has done it in a simulator?).

Saw a cool Boeing 757 flight test video where they showed them doing a series of full stalls (at altitude of course). The nose did drop quite dramatically at first.

Perhaps you can get a copy somehow. (Amazon?? Boeing store?) Test Captain Suzanna Darcy Henneman was screening it at a conference I attended. Maybe you can try and contact her about the video via the Boeing Company.

 

[TOGA]

In an EMB145 Level D sim, we turned off the shaker and the pusher and the instructor talked me through a stall, intentional spin and recovery. I was very surprised at how violently the "airplane" reacted. My Jepp binder just missed my face and the right side of the Captain's head as it flew across the cockpit from the shelf by my right thigh. We lost almost 12,000 feet, and the instructor seemed to think that that was a decent recovery!

 

[profile]

OK, time for another interjection. One of the classic errors we have seen is various instructors (sometimes endorsed by the training dept itself) demonstrating things in a non-engineering sim that even an engineering sim has not been programmed to accomplish. There is not a sim out there (ESPECIALLY a training sim) that can replicate the actual aircraft handling qualities in a full stall, let alone a spin. Period.

 

[TOGA]

Yeah, Profile, can't argue with that too much. Questionable training value, too. We were done with the training event, and it sounded kinda fun. As for the sim 'knowing' how the a/c would behave, supposedly ours are extremely close to real. This is because one of our crusty, hard-ass old instructors (that's meant to be a term of respect) did a whole bunch of pretty hard core test flying in the a/c, then transferred the data from the a/c to the sim. Supposedly, this greatly reduced the amount of interpolation the sim has to do in those situations you'd never attempt in the a/c.

 

[Vortilon]

I have to agree...simulators are only built to faithfully duplicate certain areas of operation. I had to fully stall an ERJ135 and 145 on aircraft acceptance/delivery flights in Brazil (with factory test pilots) and its a very docile airplane....just loses a lot of altitude.

That instructor should just stick to the syllabus...

(btw, if this hard-core instructor is who I think he is [Commander Abij....] I'd take the stories about him with several large grains of salt.)

 

[TOGA]

Hey, quit peeing in my Cheerios, dammit!! Geesh, we were done . . . it was fun (and done in that context)! You guessed it . . . the Commander. Yes, I'm aware that's he's a legend in his own mind. Nonetheless, he's a good instructor, and a fair check airman.

 

[njcapt]

As part of some demonstration maneuvers (in the sim) while in initial training at ATA, we did some deep stalls while at FL300. The 737-800, at moderate enroute weights, broke sharply from 15° pitch up to 25° down in about 2 seconds. It took more than 5000ft to accelerate to an indicated airspeed that allowed even the most minor increase in pitch (therefore, load factor) that didn't cause the stick shaker to activate. The best recovery I managed was to level flight in 12,000ft.

Ergo the stick shaker and stick pusher.