Full Throttle Emergency - Dead sticking a Pawnee short final

[. ._]

This thread got me thinking.

Could someone with a stuck full throttle control descent by turning the mags on and off like in the old WWI biplanes? Would a windmilling prop start an engine stuck at full throttle?

-istp

[Adam Oke]

Oooff ... Good question. I can hear the burping and farting of the engine now

[Chuck Ellsworth]

I didn't bend any aluminium and I'm happy.

You could have wrecked the thing and not bent aluminum Adam, the Pawnee is made out of 4130 steel tubing and fabric....

[Strega]

This thread got me thinking.

Could someone with a stuck full throttle control descent by turning the mags on and off like in the old WWI biplanes? Would a windmilling prop start an engine stuck at full throttle?

-istp

YES!

[Strega]

Was this really a forced landing?

He was in control, and chose when and where to pull the mixture. The engine did not quit!

Pull the mixture, cut the mags, turn off the fuel ... and for your sake leave the master on for final next time ... you tell me if the engine quits. Go read about windmilling props and tell me how efficient they are for producing thrust. When all goes quiet let me know if you're deadsticking the aircraft to the ground or not.

I agree that I had control, and I was safe. I mean I had half a tank of fuel and no where but up to go ... plenty of time to sort myself. I was safe only because I had thought things through and did not panic. Go read some accident reports and see how many result in death from minor incidents and pilots panicing in the cockpit.

Thats for the congrats though. Call it what you want; Call it a deadstick, call it a floppy stick, call it a glider, or call it a plane with a neat spinney thing that did @$#! all when I told it to stop. I didn't bend any aluminium and I'm happy.

This is what most pilots lack! see my post above.

again not picking nits here, but if you had half a tank of fuel, could you not have flown around until you had say a qarter of a tank?
Ive never flown a pawnee, but I dont think you would be able to exceed VNE in level flight at max power. perhaps you may over-rev the engine slightly, but big deal. (I have a friend with a pitts that routinely runs 3400RPM (IO-360) and has no problems whatsoever)

I guess my standards are just too high.

[Adam Oke]

I didn't bend any aluminium and I'm happy.

You could have wrecked the thing and not bent aluminum Adam, the Pawnee is made out of 4130 steel tubing and fabric....

I'm sure theres gotta be aluminum somewhere . Good 'ol sturdy Pawnee ... tough as nails.

[Adam Oke]

For some reason I've got the feeling someone will come back saying nails arn't made of steel

[Chuck Ellsworth]

Adam, I bought the first Pawnee 235 to come to Canada in 1961 ( CF-NVY )

The Pawnee is a neat little airplane and the cage the pilot sits in is stressed for around 40 G's as I remember....that ought to really stretch your dick when it comes to a stop.

...If you want to do loops they are easier with the spray booms removed....so someone told me.

[Strega]

now now cat,

a pawnee is not certified for loops!

you must be yanking our chains here!

[Chuck Ellsworth]

I sometimes get disoriented and my steep turns get 90 degrees out of reference to the horizon...

...but I'm going to get Hedley to fix that problem for me...

I would rather have someone from TC show me where I'm getting confused but they don't want to help me anymore.

When you have survived as long as I have you don't really give a fu.k what anyone thinks anyhow...and you can claim senility which means you are handicapped and protected by law.

Its a win win..

[bandit1]

Any single engine plane can be looped safely. If done right, you can do it maintaining positive g's and not exceeding 2 or 3. Right Hedley?

You'd know better than me but I've done loops with 182's, 206's and some turbines as well.

I've always wanted to try it on floats but never had the balls to do it with fear of loosing too much speed over the top. Anyone try it with a floatplane? I'd love to hear about it!!!!

[l_reason]

This thread got me thinking.

Could someone with a stuck full throttle control descent by turning the mags on and off like in the old WWI biplanes? Would a windmilling prop start an engine stuck at full throttle?

-istp

I dont think controlling your power with the mags is a good idea, I think you would be setting yourself up for some a big backfire when you turn the mags back on. Rather then using the mags the mixture would offer better control without the risk of backfire. Most engines will keep turning long after they stop making power as long as you keep the airspeed up. I've shut down the engine on mine at altitude (over an airfield) just to see how the glide would change withe the engine windmilling and with the prop stopped. Mine stops turning at about 60kts and starts turning again at about 100kts.


Adam I'll be away until may 11, if your around after that we'll go up and turn some money into noise.

[Lommer]

Actually I_reason, I think you may have hit the nail on the head. I agree that turning the engine off and on with the mags would likely wreak havoc with it, even if it did work and got you down safely. What you said got me thinking about is that special group of pilot-owners out there that like to operate their aircraft using a method called Lean of Peak - Wide Open Throttle (LOP-WOT for short). Basically, once they're cruising, they stick the throttle wide open, then lean the mixture until the engine RPMs drop to the desired level, and in flight they adjust the power using the mixture. This ensures that they're always running on the lean side of peak CHT/EGTs, whereas conventional wisdom is to run slightly on the rich side and use the throttle to adjust power. LOP-WOT advocates report very clean engines at overhaul and reduced fuel consumption, but many fear to try it due to the high possibility of cooking a cylinder or bad vibrations on some engines. Theres a good intro to the whole theory at a pilot blog I read occasionally: http://www.megginson.com/blogs/lahso/20 ... 3/leaning/

You can see where I'm going with this, so I'll throw it out there for debate amongst those who know more than I do. Could Adam (or anyone with a stuck throttle in the future), have simply pulled the mixture back slowly (and carefully!) until the power dropped to a level that would permit a safe descent? Would the power be consistent through the descent or would the mixture need to be adjusted too much to make this worthwhile? Would operating the engine in this manner, even for the very short time required to land, be likely to cause damage to the engine? Is the risk of engine damage worth the peace-of-mind and added security of keeping the engine running vs. chop-and-drop?

[Hedley]

Do NOT turn your mags off, then on again, with
any power setting above idle, unless you are happy with
exploding your exhaust off the aircraft.

Ever accidentally flipped the mag switch to OFF during
the runup, then instinctively turned it back on again
after an instant? If you ever have, you won't forget
the incredible BANG as the unburned gas in the exhaust
is lit off. This is called an afterfire btw, not a
backfire, when the burning occurs up through
the intake manifold and carburetor.

Going to one mag can help a bit but not much. Carb
heat (if ya got it) might help, too.

Yes, leaning the mixture past max EGT to LOP is a
better way to try to reduce runaway power output.

P.S. I've had a stuck throttle years ago, too. Mixture
went to lean on downwind abeam the numbers, and I
landed.

P.P.S. Yes, almost any normal or utility category
aircraft can be rolled and looped by a skilled
aerobatic pilot, who can keep the G and airspeed
within limits, regardless of the aircraft attitude.

I don't recommend it, though, unless your name
is Bob Hoover or Tex Johnston or Delmar Benjamin,
all of whom were phenomenal pilots because they
spent a lifetime developing their stick & rudder skills,
and interestingly enough, were all not-so-cordially
detested by their regulator. Something of a
pattern there, I guess.

Even where it is legal to do so (other countries)
I don't like doing aerobatics in aircraft with
gyros - it just destroys them, and I don't
like to do that to aircraft. I seem to spend
several hours working on aircraft for every
hour that I fly, these days.

Back on topic ... Adam did good. Stop
by CYSH, I'll buy the beers, Adam!

[SeptRepair]

The Pawnee is a neat little airplane and the cage the pilot sits in is stressed for around 40 G's as I remember....

I had a buddy years ago smash his Pawnee 150 doing hydro line patrols. He was focusing on a video camera we had installed and wasnt watching his airspeed. Anyways, he hit the trees at about 75 ft. The aircraft fell straight to the ground with the right wing leading. The aircraft hit the ground and the other wing folded over top of him in the cage trapping him. We had previously cut the hopper up and the upper section was all that remained to fair in the top of the fuselage. The lower area was covered over in plexiglass and fortunately for him, when he came to, he managed to kick out the bottom and walk to a nearby logging road and wait for help. One hell of a good engineered cage for the pilot to sit in.

[Strega]

The Pawnee is a neat little airplane and the cage the pilot sits in is stressed for around 40 G's as I remember....

I had a buddy years ago smash his Pawnee 150 doing hydro line patrols. He was focusing on a video camera we had installed and wasnt watching his airspeed. Anyways, he hit the trees at about 75 ft. The aircraft fell straight to the ground with the right wing leading. The aircraft hit the ground and the other wing folded over top of him in the cage trapping him. We had previously cut the hopper up and the upper section was all that remained to fair in the top of the fuselage. The lower area was covered over in plexiglass and fortunately for him, when he came to, he managed to kick out the bottom and walk to a nearby logging road and wait for help. One hell of a good engineered cage for the pilot to sit in.

It must have been designed by an ame

[Meatservo]

I think what we're forgetting here is how funny ISTP's phoney news report was. The only thing missing was " The Piper Cub, made by Pawnee of America, was flying without a flight plan, according to a representative of the ministry of transport...."

[alctel]

“Pan Pan, Pan Pan, Pan Pan. Paraparaumu Traffic, Piper Pawnee …”

As already stated, I would have lawndarted while trying to get my tongue round that!

[Stearman]

Yeah good job buddy.

Don't turn the mags on and off - agreed.

[iflyforpie]

haunting

[Stearman]

The Master in a Pawnee only is required for radio if ya have one and cranking the engine over.

She does glide like a stone though.

[Jim_12]

You loose an engine in a Pawnee just point your toes cause thats where you will end up

[BoostedNihilist]

If you crash with the master off, only the battery leads can short.

baaaah

The only way the above logic work is if the steel tubing is isolated from earth, which, during a crash can not be guaranteed.

If you turn the master off and crash, and the positive wire to the switch is compromised, and there is no fuse between it and the source ,that wire can short and burn you down.

Even a 14ga. wire can produce enough heat when shorted to start a fire.

I'm not sure about the current through a pawnee master switch, but the 172 master swithces, unless controlling a relay, look like they could flow maybe 15/20 amps max constant.

[Chuck Ellsworth]

You loose an engine in a Pawnee just point your toes cause thats where you will end up

You sound like you are a real high time pilot with lots of hands on experience.

Could you take a few minutes and explain to us with less experience how you came to the above conclusion?

[TFTMB heavy]

Nice work getting her down on the ground in one piece.

I humbly suggest to always ask for the services and if you are in an emergency situation, ie shutting down an engine, you say MAYDAY not PANPAN. Nobody will ever give you a hard time for either.

One again, nice job.

Martin