PC 12 practice turn backs after simulated engine failure after take off
 

Part of the conversion syllabus of pilot training on the PC12 (RFDS and private operators) includes practice emergency turn-backs to the departure runway following a simulated engine failure after take-off. Is this a manufacturer's recommendation?
It could be argued this goes against everything that pilots are taught at flying schools when learning to fly because of the inherent risks of stalling in the turn at low speed and low altitude. When did that change?
The RAAF taught turn backs a long time ago, but changed that after several fatal accidents while practicing.

With the PC 12, what are the minimum required altitude and airspeed parameters (and max acceptable downwind component) before an engine failure turn back is contemplated?

A turn back can be a very nice option to have albeit a bit of an advanced one.
Few airplanes respond well to a panic induced yank and bank.
It takes a (relatively) cool head and understanding the dynamics to make it work.

The RAAF still teaches them and practices them in the PC9. But I guess it's a little different because if it all goes horribly wrong the pilots can step out via the ejection seat.

There are strict gates that must be met and a turn back is limited to the QFIs.

As for manufacturers recommendations? I know Pilatus teach it at the factory for the PC7,9,12 and 21.

Your initial rate of climb has to be significantly greater than your gliding rate of descent to allow for the extra distance flown in the turn and realigning with the runway. No doubt Pilatus did the maths and worked out when it would work and when it would not.

I think I saw a video on youtube of a PC12 doing a turnback?

Can't comment on the PC 12 but in a 208 the issue generally is running off the end, not ending up short. So unless it's performed incorrectly it shouldn't be an issue. As to the decision to use it or not, that's a different kettle of fish.

it could be argues that a lot of things taught at flying schools are "sub-optimal" because they were designed to cover ass for sub-optimal students. Or because that is what their instructor taught x 10 generations thereof.

As recently as this morning, John Deakin said to me There have been threads on this before, and my "take away" has been to simply KNOW YOUR AEROPLANE and know it well.

In my plane from 500-600 feet I am at risk of running off the far end and into the fence :eek: At 400-500 it is 45 deg turn, best glide, flap as required when sure of the field, and land, brake heavily. In the 300-400 range if light, no problem, if heavy, use the energy to find the best area to land as you will not easily make the runway, but you should make something flat enough on the field.

Could I do this in a 172, probably not, or an Archer, or even a PC12 (I know it will) so even if I know it will, I need to have trained for it.

That is why the RFDS and others teach it. If you can do it from 29,000 feet or 400' the rules are much the same, because the laws of physics do not alter much ;) It is all about how you manage the event. How you prepare for every takeoff. Expect the failure and be pleasantly surprised when it doesn't.

:ok:

A turn back is a manoeuvre, which if competently trained for, competently practiced and competently commenced from above a safe height, can be executed successfully.
To me, the training and practice is most important. And another good idea is a buffer in the minimum height practised (ie when you know you're going to practice one) vs your briefed height for normal ops - to allow for the "Oh sH$t" factor...

See:

https://www.youtube.com/watch?v=Q0IbtR0GwDE

and:

https://www.youtube.com/watch?v=s9vIZ_k8iYM

Sleepy,

I have a figure of 800' in my mind but it's been 14 years since I did one. If its not 800 it's close. It was a blanket not below height.

The PC12 is an amazing glider. It handles the turn back very smoothly and easily and safely. Unlike a PA28.

Any details what accidents and when the change sheppey? As far as I know it was still in use on the last Vampire course. Macchi at Nowra had a successful turn back in 1982 after the engine swallowed a bird whilst loaded with a passenger plus practice bombs and a minigun pod.

http://i98.photobucket.com/albums/l2...A.gif~original

The PC-12 is essentially built around its wing which means it is possible to land on the same runway that you took off from above 750 feet right out to 75nm downrange. The old way to get it on the ground was pretty spectacular as well. Get to 5nm (from memory) point it straight down to Vne level out and do a perfectly normal circuit.

Excellent aircraft.

Ah yes, the 1:1 glide approach / cloud break. 7nm@7000', 6 at 6, 5 at 5 etc and level out at 700? feet and you can make any threshold. Even more fun (to practise) than the turn back :)

Essentially, the reason why turbine PC12 and similar aircraft do turn backs contrary to what is generally taught in flying schools is performance.

Most flying school aircraft are not capable of the kind of climb performance which makes the turn back manoeuvre achievable and safe in something like a PC12.

The other thing that makes a difference is currency. For example, RFDS pilots are practicing this regularly - generally every six months...

Commonly known as "practicing bleeding" like mixture cuts in light twins to simulate engine failures after take off.

So it seems you have a problem with the procedure in a PC12, without knowing how it's practised or flown. Nice work. The PC12 is no Vampire with which you are obviously familiar.

In 2002 I was on vectors for ILS6 at KTTN. I heard an Rwy24 departure check-in climbing to 2000. The PC12 pilot subsequently lost power, made a course reversal in IMC back to RWY6. At the time, I didn't realize this was a trained procedure. The synopsis can be found below.

here

Would seem not CS. Shortly before he retired, the Governor General, Lord Casey, visited Pearce.

Previously, a young Navy student had been ordered to attend the CFI's office, and given the instruction that he was to present himself at XXXX hours on the following Saturday morning prepared to aviate. Student wondered what was up, as weekend work was never done, and he was the only one so ordered. Dire thoughts were at hand.

Turned out the G-G wanted to listen in on the "patter" used during a sortie. The arrangement made was for him to listen in on the tower frequency while the student and CFI conducted a session of turn backs, both to the cross runway and 180° in a Vampire.

G'day Megan,

My comment to Sheepy (who used to fly Vampires I understand) was that the turn back procedure in a PC12 is a lot simpler than that that pic you outlined above. No converting speed to height. The PC12 just glides amazingly well.

When we did my endorsement, out in the training area the checkie told me to pick a spot for a forced landing. I picked what I thought was the only likely spot -far from perfect but survivable - using my judgement of radius from piston singles. He asked why I didn't pick that nice big open salt pan way over there. "Um, because we won't make it..." was my reply. With a wry grin, he said yes we will, point her that way. We made it.

I am sure the PC12 and the PC9 are fine aircraft which glides very well providing the prop is promptly feathered. But what if for some reason the prop is inadvertently left windmilling? Do pilots practice for that eventuality? Of course we can play "what if's" until the cows come home." After all there have been several GA accidents over the years where a light twin has gone in after engine failure after take off and the pilot was so busy he never got around to feathering the dead engine prop. The C402 Aerial Ambulance fatal crash after taking off from Essendon 35 is a case in point.
But you are quite right - I have never had the pleasure of flying these turbo-props and unfortunately it is all too easy to be talking out of my arse which you alluded to with "Nice Work."
On the other hand I did have the unpleasant experience of being on the Court of Inquiry and thus seeing the awful aftermath of a Winjeel turn back after a practice engine failure that went wrong resulting in both pilots being burned to death on impact. That experience tends to concentrate your mind about the pros and cons of turn backs and whether or not practice makes perfect or even increases the chances of an accident based on the adage get away with something long enough and the perceived danger diminishes.

I guess if Pilatus and the RAAF are perfectly happy to teach the manoeuvre as a safe option to landing ahead its OK with this scribe.

The turn back discussion is a valid one and as there are many variables form aircraft design and performance to pilot experience. Trying to find a generalisation yes or no is going to get into heated discussion.

My throw away comment was aimed at the fact that you asked for the performance data presumably to make an informed decision and discussion, then throw that approach away with the prejudiced practising bleeding comment.

Sheepy,

A lot of the difference in glide with a windmilling prop can be attributed to turbine vs piston. To turn over a piston engine that isn't running requires effort to compress the air on the compression stroke. A turbine engine like the PT6 is a lot easier to turn over because the free turbine does not compress the air in the engine.

The energy to turn the engine has to come from somewhere and it comes from the potential energy of the aircraft through a higher sink rate.

Reciprocal turnbacks can be a killer. Turning back to a cross runway is generally more achievable. Practice turnbacks are good training but its in the context of a canned scenario, with everything going according to plan and with forewarning. A real engine failure will never be like that. Having said that practicing a turnback once every six months in the aircraft is, in my opinion, setting yourself up for a scare or worse so I'm strongly of the mind that practice turnbacks belong in the simulator only. If you must practice turnbacks in the aircraft then it must be properly supervised and documented. Even then the scope for someone to go off script is precipitously high.

If the PT6 doesn't feather no one you'll have plenty of sink rate!

Feathered v unfeathered in the PC9 is a RoD difference of close to 2000 fpm. With a feathered prop you'll get a RoD of 2000fpm, unfeathered is close to 4000fpm.

The prop failed to feather on a PC9 in flight shutdown in 2011, leaving two pilots swinging under parachutes. The aircraft crashed about 1-2nm short of making it back to the airfield.

Do the Central Section and Western Ops have a simulator these days for training/ practice turn backs and the cloud break proceedure?

King Air pilot training has moved on from assymetrics in the aircraft to comprehensive simulator training. Just wondering, has PC12 pilot training made a similar step forward?

No Sim. All training is done in the aircraft. It is a real eyeopener when you see it done the first time.

I've done it probably 20 times in my aircraft and can get away with 280 ft, with a 90 degree crosswind up to about 5 knots. Once those wind figures change, it all goes pear-shaped.

Certainly not for the beginner and certainly not for the experienced when operating beyond known and tested figures. If I added a passenger I'd have to add close to 100ft. If you are going to do it, it would need to be a sizeable margin to be sure you could do it every time, be at the top of your flying game, be well practiced and be alsolutety ready to action on a shutdown.

Do you think the pilots leaving might have had some effect on best glide performance? The fact that an aircraft without pilot or canopy crashed short of the runway is no proof that it wouldn't have made it otherwise.

Do you have an airspeed and height gate or just a height?
What rule of thumb for temperature and density altitude do you use?
What analysis of the 'power loss' do you allow for before deciding to shut down the engine?

That's the issue... power loss... what constitutes power loss. Do you shut down at the slightest splutter? DA, who knows, that's at sea level 1013. Too many variables even on a simple light aircraft let alone something big to be safe.

Add a massive margin and of course you'll get back, but at that point it's hardly a turn-back on takeoff.

In the end the lack of a canopy made no difference. The pilots departed the scene below 300 feet (below MEDH). Unfortunately the full accident report doesn't seem to be available online.

That is a very good question. In the Sheppey Post No 19, he mentions the Winjeel fatality (which happened at Point Cook). Shortly after take off when about 700 feet, the instructor announced to ATC "Simulated engine failure". However the student failed to immediately lower the nose although the aircraft was observed to start a steep turn. Passing through 90 degrees the Winjeel stalled and flicked into an incipient spin.
The instructor presumably took action to recover from the incipient spin as he had the wings levelled shortly before impact but the aircraft hit the airfield at a high rate of descent. The landing gear collapsed, the battery broke free at impact causing arcing and ignited fuel from the fuel tank adjacent to the battery. The aircraft caught fire and the two pilots were unable to open the canopy to get out before being overcome by the flames in the cockpit.
Fire crews were on the scene within two minutes but due to the haste to get foam going, the driver inadvertently selected wrong selections and there was no foam. A fireman who tried to force open the Winjeel canopy was driven back by flames.
While the simulated engine failure by throttle closure started the chain of events in this case, a ditching into the sea straight ahead (simulated) would have been the safer option rather than a turn back with its associated risks of mis-handling at low altitude.

This would suggest that even experienced RAAF pilots who are QFI's appreciate that a high degree of flying skill is a vital factor in the conduct of a successful turn back manoeuvre; otherwise why not allow students to practice these solo? In the case of the Winjeel accident, the instructor was certainly experienced yet a vital few seconds slow to react to the student not lowering the nose prior to turning back.

Isn't that why CASA mandated emergency manoeuvres for certain aircraft types must only be done in a simulator?

This comment from a former RAAF CFI of CFS in the era when turn backs in Vampires were first introduced at East Sale where there were two runways

Quote: "It's a bit like airline pre take-off briefs as you and I would have done them.

The brief would be specific for the take off.

When discussing turn backs they are thinking of back to the same runway . but as I mentioned before ...off on 27 at East Sale a turn to land on runway 02 (I think) would be possible PROVIDING the aircraft had enough ENERGY...i.e. height and speed and distance from the field.

So all the talk about great gliding and stuff is only applicable when the 3 issues I mentioned are satisfied ...otherwise in the case of the military PC aircraft it would a be a zoom and boom eject I expect.

IT IS ALL predicated on the three items above and a specific brief for the specific take-off runway ...think about the brief for EFATO at Kagoshima in Japan.

If they want to be hero's today and dead men tomorrow let them be. Practise it enough and statistically the result will be predictable." Unquote.

From ADF Serials, and sounds like the accident to which sheppey refers.The last sentence tells me that it was what the crew did, not that it was a procedure endorsed by the RAAF, and on which crews were trained for on that particular type.

I can offer some light re turn backs on Winjeels. I was a QFI at Uranquinty in 1956 on Winjeels when the type was first introduced. Certainly turn backs were never considered as a training exercise.
Several years later circa 1960 we had a Winjeel at No 10 Squadron Townsville along with the Lincoln Mk 31 Long nose. By then I was the squadron QFI on the Lincolns, Winjeel and the unit Dakota.

A new Squadron Leader arrived on posting to Townsville to be flight commander. He came from CFS where he was an instructor. There were Winjeels at CFS and he was experienced on type.

As was customary, it fell to me to give him a dual check on each aircraft he would fly at Townsville, including the Winjeel. We took off from the then Runway 02. It is a long runway. At around 200 feet I closed the throttle and announced "simulated engine failure" full expecting he would lower the nose and land straight ahead on the ample length remaining. I planned to tell him to go-around once it was clear he could easily land ahead.

Instead he simultaneously lowered the nose and ripped into a 60 angle of bank through 180 degrees turn to land back the way we came. I was unable to prevent this happening as any interference in the turn would be potentially dangerous. The aircraft touched down nicely and we stopped. ATC were not expecting this and nor was I.

After a short and serious discussion about this antic he explained that CFS taught turn backs in Winjeels. I had never heard of this before.

I think it's excellent that someone has had the balls to consider that a turn-back is a sensible manoeuvre for a high performance aircraft. The moment you achieve a climb rate in excess of your glide angle this procedure becomes sensible. All you have to to is ensure you have enough sky underneath you to do a 180. The rest is in training. Not to do so risks wasting a valuable airframe. It's about time thinking was introduced to aviation.

PM

We practice this in the PC12 (usually in OPC), never below 1000ft AGL and in VMC of course. In sim I have tried it little lower. It certainly is doable, however many a pilot has stalled and spinned performing that turn..

Coincidentally (or scarily) a suggested post popped up in my Facebook feed from Martin Baker today. It has some pictures and a first hand account of th PC9 crash in East Sale.

CS, from a student about to graduate at Pearce.

I sweated that out even reading it:ouch:
The rate of descent with a windmilling prop in a turbo-prop is startling. During my conversion to the RAAF Viscount (four Rolls Royce Dart turbo-prop engines) many years ago, we were doing circuits on Runway 35 at Canberra. While downwind on one circuit, the instructor told me to try a glide approach. That meant maintaining circuit height on base leg until it was judged that if we closed the throttles to idle we should be able to get in from there. In retrospect the whole exercise was potentially dangerous and we should never have even contemplated it. But the instructor had been shown this when overseas being checked out on his own conversion to the Viscount

I held height until I was absolutely certain we could glide safely from throttle closure then smoothly brought all four Darts to idle. The speed drop off was alarming and we had to lower the nose a lot. The rate of descent soon became drastic and it became obvious we were going to land a mile short of the threshold. My guess was the glide angle at idle was around 10 degrees.

Naturally that wasn't on, so power was quickly re-introduced to approach power to get back to hold the normal three degree slope.
The lesson learned was never to under-estimate the glide angle with a windmilling turbo-prop.