Anyone ever reverse inflight w/Garrett??

[low-n-slow]

I guess it just depends on the airplane. The SF340 is one airplane in which it was emphatically stated, in no uncertain terms, to never, ever pull the props behind the idle gate in flight. We had an aircraft experience a dual catastrophic engine failure as a result of this. As a result, all Saabs were retrofitted with a weight-on-wheels activated idle stop.

Other airplanes may be authorized for inflight beta/reverse usage. I am not specifically aware of any, but if you are flying one, more power to you. Knock yourself out.

LAXSaabdude.

Good answer, I wondered why others answered with such empathy that instant death is a resultant of reversing a turbine powered propeller driven airplane while in flight.

 

[Jmmccutc]

Myth Busters...good call!!! I like to see that investigated

 

[j41driver]

Re: Re: yes, a very stupid question

I have put a PT-6 in Beta while in flight...

WHY??

 

[starchkr]

This has happened before in a few Caravans, where the engine went into beta or reverse uncommanded and most of them the pilots were able to recover. Now i think the caravan has the PT-6 (i am not sure), but there was a thread on this subject awhile back about the caravans. Something about a valve or something wearing out and letting the engine go into reverse in a second or so. So i guess it can be done, but i wouldn't want to be the one to do it.

 

[low-n-slow]

Re: Re: Re: yes, a very stupid question

WHY??

Why not? The opportunity was granted a couple of times and I took it.

I am not regulated to the point in my business that flying cannot be fun, is it in yours?

 

[sky37d]

not a turbine, however

It was a not uncommon practice for Seabee's to be intentionally put into reverse, just before touchdown, on water.

 

[JAFI]

Apples and oranges

The original poster asked about a Garrett engine going into reverse as I recall.

First of all, not all turboprops are built the same. A Garrett is not the same as a Pratt or as a GE CT7 (in the SAAB).

The Garrett and CT7 are direct drive, through a gearbox, to the prop. The manufacturer does not authorize going into reverse in flight. Think of the stresses you are putting on the gearbox and engine.

The SAAB (A model) beta Stop on the throttle quadrant is nothing more than a ball bearing and a spring to stop the power lever from going into Beta. If you pull hard enough, you can go into reverse in flight (at least you could. I’m not sure if any changes have been made). This happened in 1991 while on a type ride in the aircraft at 3 am. The aircraft went inverted in as much time as you can say "aw Sh#t". The inspector in the jump seat was not pleased with the check airman who slammed the power leaver to Idle, simulating a failed engine. The check airman was able to push the power lever up and regain control of the SAAB.

The PT6 (20 to 67) is another animal. The prop is not connected to the turbine section and there are some aircraft, which have been known go into both beta and reverse in flight (I know of both the Shorts 330 and 360 into beta and in the Twin Otter into full reverse (going straight down in an emergency descent)). I do not know of any flight manual in the US, which allows this. In other countries they sometimes do what they want to do.

Think of what you are doing here. You just created two 10 to 15 foot diameter speed brakes in an instant. Is this such a good idea? Will it fall from the sky? It depends on the type of aircraft and what damage has been done, if any.

Can this be done? Maybe. Is it a good Idea? Maybe not.

Are you operating outside of the aircraft manual? Would this make your boss/owner/mechanic happy or not?

Each engine is almost a million dollars to overhaul depending on damage. You may not damage the engine enough to see it this time. You may find out later if any damage happened.

My suggestion: Just operate the aircraft in the limitations of the manual and it will last longer and cost less.

 

[350DRIVER]

At what point in your career did you know that beta, or reverse would be instantly fatal? And dont give me this common sense crap. I have no experience with with reverse or beta. I have heard stories of people using them in flight and not resulting in a crash. But having no experience I would love an enlightend answer. I wonder if you actually have an educated answer, or did you just feel like jumping on board and bashing someone?What are the purposes of this board? To ask questions and educate ones self. I suppose that the other is to denigrate those with less experience than your self.

USC,

When did I ever state that reverse would be "instantly fatal" as you put it?. I thought so... For you to ask such a ridiculous question about putting the engine into reverse in flight makes me seriously question your reasoning, knowledge, background, etc, etc,.. I guess common sense may illustrate a few key points if you would take the time and learn about the proper operating procedures (normal), emergency procedures, concept, etc, etc. I was simply responding to this person's questions which I thought were a tad off in right field. I sure hope I am not a passenger on Cwazy Clown Airlines when you get the call. I guess that just about sums it up.

Study a little bit about "loss of control" attributed to this on the NTSB pages, I bet you may find yourself a few examples..

I would love to hear the stories about people using this in flight as you have stated, so I will wait patiently... I can only imagine what is to come.

3 5 0

 

[Big Duke Six]

FWIW

For my 2 cents, I have inadvertently gone into beta while on short, steep approaches flying Metros. The Flight Idle gates were fairly worn on some of our ac I guess, and so I'd bet a fair amount of money that I wasn't the only one that experienced this. It's happened at altitude as well, coming down of course. Heck, maybe I pulled them up over the gates subconciously, who knows. Some people have told me they have, at least once, intentionally pulled the props back VERY GINGERLY into beta when they needed to get down. The effect is dramatic, but not life threatening - at least when I have seen it. I would not recommend this, but I can say with certainty that I, and they, are still here.

 

[CatYaaak]

USC,

Study a little bit about "loss of control" attributed to this on the NTSB pages, I bet you may find yourself a few examples..
is to come.

3 5 0

Years ago I seem to remember reading about a guy flying Casa 212s for some commuter airline (up around Chicago I think) who loved to do this "in-flight Beta" thing as a way bleeding off airspeed on short final...a kind of Cowboy Speedbrake method. He loved it, that is, right up until the day on short, short final he came out of Beta to flight Idle and only one prop came out, or one just came out faster than the other.

Apparently, the sudden rolling, turning and inverting action was quite dramatic, as evidenced by the resulting smokin' hole containing dead bodies.

It certainly slowed him down that day.

 

[hagen]

I once had the pleasure of being able to do this in a ac-680 sim. The result wasn't pretty. We were toast in under 15 seconds.

If you have the chance in a sim give it a try. Pop the flight idle stop solinoids, throw it back and hang on. You will be upside down pointing at the ground rather quickly.

 

[328dude]

I also found myself in a similar situation years a go in an MU-2. Same thing as the metro problems with the gates being worn out. Many a MU-2's have crashed over this and the prelim's stated that this is what happened, but no DR onboard to prove it.



My experince was a short wickard ride, but not life threatening. Would I do it again? Um NOPE!.

This manuever is not recomended for student pilots that own TFE-331's

 

[uavchaser]

Thank you for all that actually answered my initial question without coming to an immediate conclusion. Also thanks to all who flamed me for asking an odd question, isn't this what the board is for. This question was asked by a flight test engineer at work and I just wanted everyone's take on it. It was thought up as one of many possible ways to release (insert object) from a hung store situation. I have gone into reverse in piston aircraft inflight with no problems but never in the TPE-331. If the prop were not to come out of reverse I would shut off the engine, instant death, highly doubtful?. I do appreciate the 200hr. pilot comment especially since I do not have my flight time posted.

 

[xjcaptain]

JAFI, just to avoid confusion, the SF340 (GE CT7 series) engines are NOT direct drive, they are free turbines, similiar to the larger Pratt like the 120 series. The inability to use reverse (or beta) inflight has noting to do with a direct drive issue, it is strictly dealing with overspeed issues of the power turbine. To keep it simple, if beta mode is selected in flight the overspeed protections go out the window and the power turbine overspeeds and basically self destructs. Eagle proved this when they dead sticked one in. Nice job on making the field by the way!

 

[PacoPollo]

I have gone into reverse in piston aircraft inflight with no problems but never in the TPE-331. If the prop were not to come out of reverse I would shut off the engine, instant death, highly doubtful?. I do appreciate the 200hr. pilot comment especially since I do not have my flight time posted.

huh??

 

[Swass]

I don't know about the reverse while in flight, but I do know that 350 is kind of a dick. And the almighty Avbug for that matter. Couple of first rate a-holes.

 

[F70pilot]

I remember reading an accident report about a CASA 212 driver that used reverse as a regular technique to achieve huge decent rates until one day the props didn't come out of reverse simultaneously resulting in a loss of control and non-survivable impact with terrain.

 

[skyking1976]

I think the moral of the story is: Why tempt fate? I'd rather not find out what happens with props in beta without having the wheels on the ground.

Fly safe,
SK

 

[na265]

When NASA is training pilots to land the Space Shuttle, they use a GII. It is my understanding that when they are on final, the reversers are fully deployed all the way down to the ground.

 

[skyking1976]

I thought they had a sim for that...