Simulated engine failure - turn-backs with fatal results.
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Simulated engine failure - turn-backs with fatal results.
Several decades back the Royal Australian Air Force Central Flying School introduced practice turn-backs following simulated engine failure after take-off (single engine types). The height chosen was around 800 feet for prop aircraft and in Vampires you needed to have reached 290 knots to ensure sufficient energy margin, by which time, of course, you were a couple of miles from the departure end of the runway.
It was in the flying instructor course syllabus as a dual exercise only. Regardless of the reasons why such a practice was introduced, I personally thought it was a dangerous macho exercise. The RAAF lost a Winjeel and a Vampire while practicing these turn-backs, with four pilots killed as a result.
I understand that the Royal Flying Doctor Service in Australia currently do the same exercise in the PC12 during conversion and recurrent training, as do RAAF CFS in their PC9's.
Does anyone know of any measured trials carried out by a competent authority in past or recent years on turn-backs? The risks involved seem to vastly outweigh any training benefits.
In the case of the pilots killed in the RAAF training accidents, in one case the aircraft would have been better off with a simulated ditching in calm seas ahead, and the other had unobstructed fields ahead. A case perhaps of more people killed practicing turn-backs than has happened with real engine failures after take-off with forced landing straight ahead.
[This message has been edited by Centaurus (edited 05 April 2001).]
It was in the flying instructor course syllabus as a dual exercise only. Regardless of the reasons why such a practice was introduced, I personally thought it was a dangerous macho exercise. The RAAF lost a Winjeel and a Vampire while practicing these turn-backs, with four pilots killed as a result.
I understand that the Royal Flying Doctor Service in Australia currently do the same exercise in the PC12 during conversion and recurrent training, as do RAAF CFS in their PC9's.
Does anyone know of any measured trials carried out by a competent authority in past or recent years on turn-backs? The risks involved seem to vastly outweigh any training benefits.
In the case of the pilots killed in the RAAF training accidents, in one case the aircraft would have been better off with a simulated ditching in calm seas ahead, and the other had unobstructed fields ahead. A case perhaps of more people killed practicing turn-backs than has happened with real engine failures after take-off with forced landing straight ahead.
[This message has been edited by Centaurus (edited 05 April 2001).]
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Here is a study, "The Possible `Impossible' Turn" that was done using both student pilots, and experienced pilots, in a simulator. With training, all the pilots with over 100 hours of experience could successfully complete the turnback manoever from 500':
http://web.usna.navy.mil/~dfr/possible.html
While digging that one out of my archives, I found two others of interest.
"The Impossible Turn" is a readable article, arguing the conventional viewpoint, and documenting the physics opposing your safe return to the runway if the engine were to fail shortly after takeoff:
http://www.albertvilleaviation.com/impossible_turn.htm
The other, also titled "The Possible Impossible Turn" is a somewhat more technical article delving into the physics behind the first "The Possible `Impossible' Turn" It recommends a teardrop-shaped return to the runway, flown with a 45 degree bank angle.
http://web.usna.navy.mil/~dfr/aiaa1col.pdf
Centaurus, if you are interested in more studies on the subject, see the cittation list at the end of the third article I cited, and also ask a librarian to help you use a citation index to find later articles that reference "The Possible `Impossible' Turn."
http://web.usna.navy.mil/~dfr/possible.html
While digging that one out of my archives, I found two others of interest.
"The Impossible Turn" is a readable article, arguing the conventional viewpoint, and documenting the physics opposing your safe return to the runway if the engine were to fail shortly after takeoff:
http://www.albertvilleaviation.com/impossible_turn.htm
The other, also titled "The Possible Impossible Turn" is a somewhat more technical article delving into the physics behind the first "The Possible `Impossible' Turn" It recommends a teardrop-shaped return to the runway, flown with a 45 degree bank angle.
http://web.usna.navy.mil/~dfr/aiaa1col.pdf
Centaurus, if you are interested in more studies on the subject, see the cittation list at the end of the third article I cited, and also ask a librarian to help you use a citation index to find later articles that reference "The Possible `Impossible' Turn."
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The RAF banned the practice of turnbacks when it realised it had lost 2 Hawks in 3 years practicing turnbacks, and hadn't had a single real one in 20. The statistical decision was that you lost less aircraft not practicing turnbacks but telling the pilot to eject if there was no runway within 30°. (I did the ADR analysis for the BOI on the second of those Hawks, anybody with back issues of AirClues, that's my hand plot of the flightpath around Valley).
The RAF teaches no more than 30° turn and find a field ahead in light trainers (Bulldog, Tutor, Vigilant) and I seem to recall that ejection was the preferred option in the Tucano, since if nothing else that may accelerate the day when HMQ has to buy a decent basic trainer.
G
The RAF teaches no more than 30° turn and find a field ahead in light trainers (Bulldog, Tutor, Vigilant) and I seem to recall that ejection was the preferred option in the Tucano, since if nothing else that may accelerate the day when HMQ has to buy a decent basic trainer.
G
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I would never, ever advocate turning back. Yes, it has been shown in practice to be possible. However, the situations in which it IS possible are so rare, and the pilot's abilities and understanding of his aircraft so high that it could never be advocated as an acceptable practice.
Here's a Word document that may assist with all the other references above.
Here's a Word document that may assist with all the other references above.
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Ghengis. Can you give me a quick run-down on the circumstances of the Hawk accidents and the parameters needed before the turn-back became an option. Was it a local flying school procedure or CFS initiated? Anyone hurt? Did they spin in, or land short of the departure runway?
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Hopefully everything I say here is public domain, if anybody thinks it isn't for goodness sake tell me and I'll delete the offending bits.
Hawk T1a, RAF Valley, 1 July 1993. There was a write-up in Air-Clues Aug 1984.
Got airborne on runway 32, right at MTOW, with wind of 360/10. Two instructors on board (Captain was a CFS QFI in the front, student was a QWI on a CFS course to become a QFI. Throttle closed at 500ft during climb-out, initial slight turn to the left before a turnback was initiated to the right.
It seems to have been evident to the crew at about 300ft that the aircraft wasn't going to be wings level on the centreline. The throttle was fully opened, and they tried to go around. However, it takes 8 seconds to spool up an Adour, and in the end they impacted still descending with about 30° of bank, and ejected on the bounce. The aircraft didn't survive, the aircrew did, whether their careers did I don't know. At impact the aircraft was above the maximum permitted landing weight, and above the maximum descent velocity for which the undercarriage was designed in a wings-level landing.
G
Hawk T1a, RAF Valley, 1 July 1993. There was a write-up in Air-Clues Aug 1984.
Got airborne on runway 32, right at MTOW, with wind of 360/10. Two instructors on board (Captain was a CFS QFI in the front, student was a QWI on a CFS course to become a QFI. Throttle closed at 500ft during climb-out, initial slight turn to the left before a turnback was initiated to the right.
It seems to have been evident to the crew at about 300ft that the aircraft wasn't going to be wings level on the centreline. The throttle was fully opened, and they tried to go around. However, it takes 8 seconds to spool up an Adour, and in the end they impacted still descending with about 30° of bank, and ejected on the bounce. The aircraft didn't survive, the aircrew did, whether their careers did I don't know. At impact the aircraft was above the maximum permitted landing weight, and above the maximum descent velocity for which the undercarriage was designed in a wings-level landing.
G
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Ask a glider pilot.
Engine failure after take-off presents the same problems as a failed winch launch, just with a less extreme nose high attitude.
The point to be considered is current training/experience.
On a winch launch the glider pilot is constantly accessing the situation and how it changes with altitude. Initially, land straight ahead, then a dog-leg, then a 360, then a low circuit.
The glider pilot is probably also better aware of the handling and capabilities of his machine, which puts him in a much better position than most power pilots.
Most power pilots should therefore stick to the don't turn back philosophy.
However, when turning back many people fixate on the runway they have just left when they should be fixating on maintaining flying speed and control. The aim is to get the aircraft on the ground with as little damage as possible (the end result being without injury). Most airfields have ample space which is not obstructed or limited by runway lights etc.
For the record, I started with gliders and have had an engine failure which allowed me to land on an airfield, from 13,000ft. I didn't land on the runway but into the wind on a quite sufficient patch to the south of it.
Anyway, always have a can of champagne!
Engine failure after take-off presents the same problems as a failed winch launch, just with a less extreme nose high attitude.
The point to be considered is current training/experience.
On a winch launch the glider pilot is constantly accessing the situation and how it changes with altitude. Initially, land straight ahead, then a dog-leg, then a 360, then a low circuit.
The glider pilot is probably also better aware of the handling and capabilities of his machine, which puts him in a much better position than most power pilots.
Most power pilots should therefore stick to the don't turn back philosophy.
However, when turning back many people fixate on the runway they have just left when they should be fixating on maintaining flying speed and control. The aim is to get the aircraft on the ground with as little damage as possible (the end result being without injury). Most airfields have ample space which is not obstructed or limited by runway lights etc.
For the record, I started with gliders and have had an engine failure which allowed me to land on an airfield, from 13,000ft. I didn't land on the runway but into the wind on a quite sufficient patch to the south of it.
Anyway, always have a can of champagne!
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Mr. Moto, I had a similar experience with an engine failure at 10,000' in a C206.
The engine failure was caused by the fact that a skydiver had just exited the door taking the key with him!
However, I had plenty of time to plan a decent circuit onto a nice long, hard runway.
Next time that skydiver was "spotting" I managed a pull/kick that took the aircraft nicely out from under him, putting him out 10 miles from the DZ! Also, I never again flew that type without a spare key in my flight suit pocket!
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Breeding Per Dementia Unto Something Jolly Big, Toodle-pip
The engine failure was caused by the fact that a skydiver had just exited the door taking the key with him!
However, I had plenty of time to plan a decent circuit onto a nice long, hard runway.
Next time that skydiver was "spotting" I managed a pull/kick that took the aircraft nicely out from under him, putting him out 10 miles from the DZ! Also, I never again flew that type without a spare key in my flight suit pocket!
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Breeding Per Dementia Unto Something Jolly Big, Toodle-pip
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Nice to see this topic being discussed in a reasonable manner for a change!
I know that turnbacks were taught in the RAF as I was given instruction myself in them whilst on a UAS flying Bulldogs. The instructors were also required to demonstrate them during their annual CFS check ride. Not all students were introduced to them; only those of reasonable ability and with more than about 50 hours I recall.
The technique was only to be used above 450' and was pre-briefed prior to take-off bearing in mind the prevailing crosswind and other factors, including whether or not it was a requirement at all.
When the engine was 'failed', you lowered the nose smartly to maintain 80 kts (Vy) and simultaneously rolled into the crosswind with 45 degrees of bank. This minimised the turn radius over the ground. You ttransferred to instruments to maintain accurate datums and pulled to just nibble the light buffet. After 90 degrees of turn you looked out and assessed the likely landing area and concentrated on a visula approach to a safe landing, carrying out immediate actions for the failure if time allowed. You would now be at about 100' and would certainly be within the airfied perimeter, if not on the runway reciprocal heading.
The plan was the rescue would be better effected on the field than sticking out of the bedroom window of 23 Acaccia avenue.
I agree that it should not be attempted without practice, training and above all a thorough brief. I can also see that it may cause more crashes than is acceptable. Bear in mind that at the time (mid 80s) the basic trainer was the JP 3 and 5 with 0-90 bang seats and good glide performance, so the idea of training for it seems quite sensible. With newer generation seats I guess the need may be less, though I'd have thought they still taught it at UAS/JEFTS level?
It's not an impossible turn though!
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Another day in paradise
I know that turnbacks were taught in the RAF as I was given instruction myself in them whilst on a UAS flying Bulldogs. The instructors were also required to demonstrate them during their annual CFS check ride. Not all students were introduced to them; only those of reasonable ability and with more than about 50 hours I recall.
The technique was only to be used above 450' and was pre-briefed prior to take-off bearing in mind the prevailing crosswind and other factors, including whether or not it was a requirement at all.
When the engine was 'failed', you lowered the nose smartly to maintain 80 kts (Vy) and simultaneously rolled into the crosswind with 45 degrees of bank. This minimised the turn radius over the ground. You ttransferred to instruments to maintain accurate datums and pulled to just nibble the light buffet. After 90 degrees of turn you looked out and assessed the likely landing area and concentrated on a visula approach to a safe landing, carrying out immediate actions for the failure if time allowed. You would now be at about 100' and would certainly be within the airfied perimeter, if not on the runway reciprocal heading.
The plan was the rescue would be better effected on the field than sticking out of the bedroom window of 23 Acaccia avenue.
I agree that it should not be attempted without practice, training and above all a thorough brief. I can also see that it may cause more crashes than is acceptable. Bear in mind that at the time (mid 80s) the basic trainer was the JP 3 and 5 with 0-90 bang seats and good glide performance, so the idea of training for it seems quite sensible. With newer generation seats I guess the need may be less, though I'd have thought they still taught it at UAS/JEFTS level?
It's not an impossible turn though!
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Another day in paradise
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212man, yep that's something like I remember.
Understanding the mechanics of what is happening is the key. Rolling at the same time as pushing, reduced load factor providing margin from stall etc.
But you reminded me of the crosswind factor. To turn away from the wind so as to reduce the required turn.
Sorry, I think I'm preaching to the inverted!
Understanding the mechanics of what is happening is the key. Rolling at the same time as pushing, reduced load factor providing margin from stall etc.
But you reminded me of the crosswind factor. To turn away from the wind so as to reduce the required turn.
Sorry, I think I'm preaching to the inverted!
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An old chief pilot (for whom I had very little respect for many reasons) advocated turning back in a multi engined aircraft after an engine failure in say a MTOW P68 (which will not climb on one at that weight in 30C heat).
When I say turn back, his exact words were "should be able to throw it around and get it back from not very high after takeoff".
I am still shuddering at the words, and my Vmca/stall imagery flashing through my eyes of a P68 plumetting.
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Those who restrain desire do so because theirs is weak enough to be restrained.
William Blake
When I say turn back, his exact words were "should be able to throw it around and get it back from not very high after takeoff".
I am still shuddering at the words, and my Vmca/stall imagery flashing through my eyes of a P68 plumetting.
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Those who restrain desire do so because theirs is weak enough to be restrained.
William Blake
Last edited by john_tullamarine; 7th Oct 2002 at 12:53.
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Military light aircraft. As already stated, perfectly possible and practised. BUT only above 450', achieve and maintain 80kts until roll out on chosen landing direction. Wings level by (I think 100'). Only done for real if the terrain is dodgy outside the airfield eg Woodvale, Colerne.
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Apparently, the turn-back technique is coming back on the syllabus for PPLs.
At a slight tangent to the original topic, stall/spin accidents are still killing a lot of people on an annual basis. Is there something fundamentally wrong with the training people are receiving these days that they fail to maintain proper flying speed in a forced landing?
I hope the mandatory profficiency checks will give people the opportunity to practice these things more and check this rather unfortubate trend.
At a slight tangent to the original topic, stall/spin accidents are still killing a lot of people on an annual basis. Is there something fundamentally wrong with the training people are receiving these days that they fail to maintain proper flying speed in a forced landing?
I hope the mandatory profficiency checks will give people the opportunity to practice these things more and check this rather unfortubate trend.
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I think one of the coolest bits of flying I've ever seen was my first practice rope break in the glider. About 2/3rds down the runway about 400 agl, the instructor pulled the release. First RB, I just froze (apparently pretty common the first time). General vibe of "dumb ass student" from the back, then a steep 180 banked 45 degrees into a shortened downwind, then another steep banked 180 somewhere around 200 agl. Awesome.
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This subject was a hot extra-curricular topic at the recent AOPA-UK Flight Instructor Revalidation/Renewal Seminar at Bristol.
Opinion was divided; the pro- camp pointed out that there may be some airfields where turnback is a generally viable option, but only provided the pilot is in good current flying practice and has been taught/practised the manoeuvre at safe altitude. Most importantly the need to markedly increase IAS in the turn was emphasised.
Historically, it's a risky manouevre, but there are times when a controlled crash back on the airfield may be the better option than a housing estate.
The burning question left hanging in the air is: should it be taught? Or does omitting even mention of the option leave the hapless FI open to allegation of professional negligence?
Catch-22, I fear.
Opinion was divided; the pro- camp pointed out that there may be some airfields where turnback is a generally viable option, but only provided the pilot is in good current flying practice and has been taught/practised the manoeuvre at safe altitude. Most importantly the need to markedly increase IAS in the turn was emphasised.
Historically, it's a risky manouevre, but there are times when a controlled crash back on the airfield may be the better option than a housing estate.
The burning question left hanging in the air is: should it be taught? Or does omitting even mention of the option leave the hapless FI open to allegation of professional negligence?
Catch-22, I fear.
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Mr Moto. If the turn back manoeuvre is to be introduced into the PPL syllabus (presumably this is in UK?) - then lawyers will have a field day after the first fatality.
While a thorough discussion on the pros and cons of a turn back is desirable from the students viewpoint, there is no way that the manoeuvre should be practiced anywhere near the ground.
Having personally seen the gruesome sight of two burnt out aircraft (killing the crews) which crashed as a result of practice - I say again - practice turn backs, I am astonished that the lessons of the past could yet again be ignored.
While a thorough discussion on the pros and cons of a turn back is desirable from the students viewpoint, there is no way that the manoeuvre should be practiced anywhere near the ground.
Having personally seen the gruesome sight of two burnt out aircraft (killing the crews) which crashed as a result of practice - I say again - practice turn backs, I am astonished that the lessons of the past could yet again be ignored.
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The question of what to do on an engine failure is certainly part of the U.S. PPL instruction. A turnback is taught as possible above a certain altitude/airspeed and airport configuration but for single engine aircraft unless you have enough altitude/aispeed to assure you make the field the practice is to land more or less straight ahead. As my very gray haired instructor put it with an engine failure on takeoff land into the softest cheapest thing you can see through the windshield.
This was demonstrated to be graphicly one summer day when I watched a light single with 2 adults and 3 children aboard do a textbook stall, spin, smoking hole. He** of a training aid.
This was demonstrated to be graphicly one summer day when I watched a light single with 2 adults and 3 children aboard do a textbook stall, spin, smoking hole. He** of a training aid.
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Lawyers can go hang.
As pilots we have a different set of rules to live by. You control the aircraft by maintaining a sufficient flow of air over the wings. The speed of the aircraft is maintained by the pitch attitude. These are the two fundamental rules we must obey if there is to be hope of survivng any flight!
If you fail to do this the result will range from a slightly heavy landing to death.
There is simply no exception to this.
Rarely do people die falling from motorbikes on the race circuit even though they may be travelling at higher speeds than some light aircraft. People do die falling off ladders.
You can leave the house by the upstairs window or run down the stairs. Its just a question of judgement.
Spinning in is the original sin.
When the engine fails shortly after take-off you have a small radius of action-use it wisely.
As pilots we have a different set of rules to live by. You control the aircraft by maintaining a sufficient flow of air over the wings. The speed of the aircraft is maintained by the pitch attitude. These are the two fundamental rules we must obey if there is to be hope of survivng any flight!
If you fail to do this the result will range from a slightly heavy landing to death.
There is simply no exception to this.
Rarely do people die falling from motorbikes on the race circuit even though they may be travelling at higher speeds than some light aircraft. People do die falling off ladders.
You can leave the house by the upstairs window or run down the stairs. Its just a question of judgement.
Spinning in is the original sin.
When the engine fails shortly after take-off you have a small radius of action-use it wisely.