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Old 16th Dec 2012, 19:55   #1 (permalink)
 
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Nice Caravan deadstick after engine failure.

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Old 16th Dec 2012, 20:02   #2 (permalink)
 
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Another nice one Adam. Just slightly off centre line when he taxied in though
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Old 16th Dec 2012, 20:16   #3 (permalink)
 
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Nicely done.

As a small teaching point for less experienced pilots I think it is worth noting that the pilot aligned the aircraft with the runway with a massive amount of skid just before he touched down. It got the job done but is a manoever that must be performed with care because if the aircraft stalled at that point the results would have been very ugly.

Anyone know what caused the engine to fail ? If it was because he was out of gas then no amount of hero piloting will make up for the stupidity of the pilot.....
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Old 16th Dec 2012, 21:46   #4 (permalink)
 
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Gearbox disintegrated sending metal through compressor resulting in catastrophic failure, apparently. It's not normal for a free turbine design like the PT-6 to not spin, so something must have seized up majorly.

Last edited by AdamFrisch; 16th Dec 2012 at 21:47.
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Old 17th Dec 2012, 02:08   #5 (permalink)
 
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I've feathered a PT6 in flight and the blades were still turning slowly. Mind you the gas generator was still running. I've occasionally wondered if the blades would turn without the engine running?
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Old 17th Dec 2012, 02:21   #6 (permalink)
 
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If the engine is not producing power then the prop should not move if it is feathered. However there is nothing to stop movement like you would find in a piston engine or single shaft turbine, therefore if the prop is not perfectly at the feather angle it may rotate slowly.
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Old 17th Dec 2012, 04:15   #7 (permalink)
 
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Poorly executed forced landing, it could have gone pear shaped with that S turn on final. The low level turn right before touchdown was dangerous.

If that was a check flight it would be a fail.
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Old 17th Dec 2012, 10:56   #8 (permalink)
 
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He's right. That ruddered final skidding turn was inviting a stall / spin. Even from that height that would have been nasty.
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Old 17th Dec 2012, 11:45   #9 (permalink)
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True he does appear to fly quite far upwind of the beginning of the runway and then approach at quite a severe angle, prompting the sharp turn onto final. Maybe he felt it best to simply point the aircraft at the most direct route to the centre of the airfield...better to do that then aim at the start and fall short i guess.

Not really fair to criticise though just on the basis of a video, he landed the thing in one piece which is ultimately the best one can aim for...
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Old 17th Dec 2012, 13:40   #10 (permalink)
 
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Oooh get all of you!

The bottom line is, not one of you was flying that aircraft or can see the instruments in front of you or can feel the aircraft around you.

The guy did whatever he did and the result was an undamaged aircraft and nobody got hurt, what's the problem? lol
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Old 17th Dec 2012, 13:40   #11 (permalink)
 
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Ozgrade3, seconded. Sure, presented with a bloody great prepared runway like that he got away with it by the skin of his teeth with it but with very poor technique.

You've gotta love the bolleaux the bystanders come put with though!
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Old 17th Dec 2012, 14:26   #12 (permalink)
 
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Quote:
The bottom line is, not one of you was flying that aircraft or can see the instruments in front of you or can feel the aircraft around you.
We can see a grossly over-ruddered skidding turn at low speed, though. Classic stall / spin material. Made me shudder when I saw it. He was lucky, not skillful.
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Old 17th Dec 2012, 15:00   #13 (permalink)
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I think that was an awesome forced landing, of which any Caravan pilot would be proud. I do not share the opinion that excess rudder was used at any point (though I have no facts to back up my opinion). I see a large yaw to align the plane with the runway, about at the instant that the left mainwheel touched - perfect! What's the worst that happens if you get that wrong? The right wing stalls first and drops and now both main wheels are on the ground, as you straighten it out? That's okay! I have used full rudder deflection in the flare of a Caravan during crosswind testing at 25 knots direct crosswind, and the aircraft is very benign - no surprises.

Up to and including the entry into the flare, I see only turns which appear to me to be reasonably coordinated and very appropriate. Bear in mind that in a Caravan, with an upgoing aileron, you also have an upgoing spoiler - which will produce drag. If you're trying to make the best glide, I'd be keeping the turns flat to reduce drag. The Caravan wing is excellently stall resistant, and roll control is excellent up to the stall (and rudder too, if you like that way of keeping wings level approaching a stall). You really have to be trying, to spin a Caravan.

I have glided Caravans many times, they glide and handle beautifully. When you feather the propeller, it windmills very gently (though I had a very serviceable engine). If you intend to glide a Caravan, particularly with the engine still running, it is important that the prop be feathered, as there is a huge reduction in drag over the normal beta range position of the blades with the power at idle and the prop in fine pitch. One of the most scary things I have been required to do is to glide a Caravan back from an engine failure at 50 after takeoff, and slower than the required climb speed - without feathering the prop. The propeller drag in beta (which is where you have left it by pulling the power off) is huge.

I can offer nothing but accolades for this skillful flying demonstration. This pilot deserves an "at a boy" from his peers.....
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Old 17th Dec 2012, 15:04   #14 (permalink)
 
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That's just another way of sideslipping, was quite common when I flew gliders some 30 years ago (called slip-turn in english if I'm not mistaken). If you have sufficient speed (he obviously had, and I guess he had an airspeed indicator in front of him to make sure) that's a perfectly safe maneuver.

Enter "Bob Hoover" as search string into YouTube and see, how much abuse an aeroplane can take during a deadstick landing without stalling and spinning
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Old 17th Dec 2012, 16:14   #15 (permalink)
 
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"If you're trying to make the best glide, I'd be keeping the turns flat to reduce drag."

Rubbish. All turns need to be coordinated. A flat, skidding turn would increase drag.
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Old 17th Dec 2012, 16:16   #16 (permalink)
 
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My FIC course instructor taught me that the aim of a forced landing is 'survival'.
They survived....therefore aim achieved. I thought a good job well done. Thanks for that, Adam.
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Old 17th Dec 2012, 16:35   #17 (permalink)
 
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Thud, except when the wing has spoilers as well as ailerons, which I think the Caravan has. Then a turn will induce more drag than a turn in a spoiler-less plane, but I don't know how that compares to a skidding turn when it comes to drag.

Last edited by AdamFrisch; 17th Dec 2012 at 16:38.
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Old 17th Dec 2012, 16:41   #18 (permalink)
 
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Pilot DAR got it right - the pilot handled the aircraft in a way that suggested he was very familiar (and current). The last few seconds are going to be a frenzy of small, well timed inputs and what may appear to bystanders as 'risky', from the pilot's perspective is very much a situation under control. I think the best point raised by DAR is what is the worst that could happen? I can almost sense the pilot's anticipation and control over his aircraft during the last few seconds before that touchdown. He knew what he was doing, end of.
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Old 17th Dec 2012, 16:45   #19 (permalink)
 
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I believe any flat turn to be more aerodynamically inefficient, irrespective of the system used for control about the Z-axis.
And I agree with SSD. That final skidding turn just before touchdown certainly looks very poorly handled.
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Old 17th Dec 2012, 16:57   #20 (permalink)
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Yes Thud, turns need to be coordinated, I'm not suggesting totally flat turns at any time, careless wording on my part.

However, given the choice, within the range of a generally coordinated turn, I would err to less aileron than more during gliding turns in a Caravan. The Flight Manual makes no specific statement in this regard.
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