No Turning BackIs turning back after engine failure ever an option? John Laming looks at this dangerous manoeuvre.
In the 1950s the Australian air force lost several aircraft when practising asymmetric landings with one engine actually shut down. Realising it was losing more aircraft in asymmetric training accidents than in real-life engine failures, the RAAF issued a directive stopping all practice feathered landings. Henceforth, asymmetric practice was to be carried out with one engine throttled back, ready for instant power if needed.
Although aware of the RAAF directive, the Department of Civil Aviation continued to allow feathered landings and overshoots in civil aircraft, the only restriction being no asymmetric training at night below cruise height.
Over the years several civil aircraft were involved in fatal accidents during asymmetric training with one engine feathered. These included a Dove crewed by DCA examiners that crashed at Camden following a practice engine failure after take-off. A Viscount crashed in similar circumstances at Mangalore, when the instructor feathered an engine at V1 causing the pilot under training to lose directional control.
From overseas there was documentary evidence of similar accidents in training. Despite the clear lessons from these accidents, the Australian regulatory authority of the day declined to limit practice asymmetric landings with one propeller feathered, taking the view that training policy is the responsibility of the operator. Unfortunately, the reluctance of flying instructors to involve officialdom means little information emanates from civil flying schools concerning close calls during asymmetric training.
A de Havilland Dove. (Michael Benson)
Shortly after the Air Force banned practice feathered landings, the RAAF Central Flying School at East Sale included in the flying instructor syllabus a manoeuvre called the ‘Turn-back’. This was despite the long-held and justifiable view that a turn-back following an engine failure after take-off in a single engine aircraft was tantamount to suicide. Too many variables could affect the success of such a manoeuvre, not least of which was altitude gained at the time of engine failure and pilot competency.
CFS instructors initially carried out turn-back trials using the dual-seat Vampire Mk 35. Providing 290 knots had been attained after take-off, it was established that a zoom climb and steep reversal turn could place the aircraft on a glide approach back to the upwind threshold of the departure runway. This led to some pilots deliberately holding their Vampire down after lift-off in order to accelerate quickly.
Whether this technique was operationally justified remained a matter of conjecture, but the noise of a Vampire flashing over their fields at 100 feet certainly stirred up local farmers and their animals. The turn-back in the Winjeel was not speed-dependant but required a minimum altitude of 600ft after take-off. Despite the misgivings of some instructors, rank prevailed and the stage was set for the turn-back to be taught on instructor courses and then passed on to students at RAAF flying training schools. Because of the risks involved, its practice was limited to dual instruction only. That limitation alone should have generated doubts at all levels about the risk management of such a manoeuvre.
The first turn-back fatality occurred at CFS. Two pilots on a flying instructors’ course were killed when their Vampire hit well short of the departure runway following a practice engine failure. If they had experienced a real engine failure, there was little doubt that a forced landed straight ahead into fields surrounding the aerodrome would have given them a reasonable chance of survival. During Vampire training, I had carried out several practice turn-backs and felt confident that, given ideal conditions, I could get away with it. Even so, there were occasions when last-minute thrust was needed to avoid undershooting the threshold. A head wind on take-off could translate into a comfortable tail wind to carry you to the runway, but the real danger was the risk of stalling during the steep reversal turn needed to point back at the airfield. Here, the pilot was wide open to the deadly illusion of apparent slipping into the centre of the turn, which is well known to those who indulge in low flying. Additionally, if the aircraft did hit the ground short of the runway, the increased energy forces associated with high ground speed impact and exacerbated by a tail wind significantly increased the chances of injury if the aircraft broke up.
At the time, turn-backs were regarded as an exciting manoeuvre to be talked about over beers as a badge of pilot competency. Large fields surrounded East Sale aerodrome, where CFS was based. That these may have provided a better chance of survival than a tight turn-back seemingly never occurred to the staff of CFS, who continued to treat turn-backs with enthusiasm and dash. The seductive illusion of a long runway behind and their well-practised personal flying skills may have blinded them to the reality of an actual engine failure accompanied by the inevitable shock that this is the real thing. Every second’s delay in reaction could put the aircraft fatally short of the runway in a turn-back, while the drag from a seized jet engine could cause a dangerous change to the glide angle. Certainly, the RAF were involved with turn-back training on Hawk and Bulldog aircraft, losing several Hawks in the process.
The Winjeel was a basic to advanced trainer developed by the Commonwealth Aircraft Corporation, very similar to the Percival Provost. The Winjeel above is preserved by the Royal Australian Air Force Museum. (Michael Wignall / Wikipedia)
I had the fright of my life at Townsville during a dual check on a senior officer who had just arrived at the squadron. The aircraft was a Winjeel and I had simulated an engine failure on take-off by closing the throttle at 300ft. With a mile of runway ahead, I assumed (wrongly) that the pilot would simply lower the nose and land on the remaining length. Hardly had I closed the throttle when the senior officer shoved the stick forward, simultaneously screwing the Winjeel into a 60-degree angle of bank reversal turn in order to land from the turn- back. This man was an experienced instructor on Winjeels and had been the CFI of an Australian Air Force flying school. I was caught off-guard and at that height any action on my part to prevent the turn- back would only exacerbate an already serious situation.
On the ground, but into the teeth of an approaching Lincoln on final (which went around again), I threw rank out of the window and tore into the senior officer for risking our lives with such a foolhardy action. Taken aback at my outburst, he explained that the turn-back was commonly practised both at CFS and the RAAF Basic Flying Training School at Point Cook, albeit from 600 feet. This was news to me – probably because Townsville was 2000 miles north of Point Cook, and we seemed to be in a different air force. That incident convinced me that someday, someone would get killed practising it.
My fears were well founded when two years latera Winjeel crashed at Point Cook, killing the instructor and student. They had departed from runway 17 over the sea, with the intention of a practice turn-back. A southerly wind was blowing from Port Philip Bay just off the end of the runway. A solo student would not have been permitted to practice this exercise – although if a real engine failure had occurred he would have used his discretion to turn back or ditch straight ahead. With a low energy ground speed into the southerly wind, ditching ahead was the safer option. It had happened at Point Cook before and the pilot had survived with few injuries.
This, however, was a dual exercise and part of the flying training syllabus. Witnesses saw the Winjeel climb normally after take- off until reaching 500 feet over the water. The instructor advised ATC that he was carrying out a simulated engine failure and turn-back. Seconds later the aircraft was seen to turn steeply and shortly after it flicked into an incipient spin. The recovery was made too late to prevent the aircraft from landing heavily in a flat attitude just inside the aerodrome boundary. Although the undercarriage collapsed on impact, the accident was survivable as the aircraft was still in one piece.
The Winjeel caught fire and was burning fiercely by the time the rescue crew arrived on the scene one minute later. The instructor was knocked unconscious in the crash while the student was seen to be moving but surrounded by flames taking hold in the cockpit area. Unfortunately, the fire crew were unable to control the fire due to a problem with the fire tender and by the time foam was available it was too late to save the pilots.
There was no recommendation from the Court of Inquiry that the policy of practice turn-backs be reviewed in the light of the two fatal accidents. As the junior officer on that Court of Inquiry, I had little influence on its findings. In those days, members of Courts of Inquiry and of the RAAF Directorate of Flying Safety (DFS) received no training on accident investigation techniques. It was invariably a case of learning on the job. This invariably resulted in the investigators being forced to make an intelligent guess as to the cause of the accident and there was invariably reticence to delve too deeply into deficiencies up the chain of command.
Why were turn-backs introduced into the RAAF syllabus of flying training? There are several possibilities. The RAAF had an agreement with the RAF to exchange selected officers on two-year postings and CFS usually had an RAF instructor on staff. Traditionally the RAF CFS syllabus of flying training had been held up as the ideal and perhaps because of this, the training syllabus for flying instructors in the RAAF was similar to CFS in England. It is possible the idea of turn-back training may have emanated from one of these exchanges. Certainly CFS had taught turn-back training. On the other hand, the idea may have been the brainchild of the Commanding Officer or CFI of the day at RAAF CFS. These appointments were held in high professional regard in RAAF circles and few were inclined to question their pronouncements on matters of pure flying techniques, less they be regarded as heretics.
Talking recently to an RAAF CFS instructor, it surprised me to learn that practice turn-backs were still taught at CFS – this time in the PC9. Again, it was a dual exercise only and I thought of the poor pilots back in the 60s who lost their lives practising for the real thing. The CFS instructor had not been born when those bodies had been pulled from the wreckage of the Winjeel at Point Cook and the Vampire at East Sale. By now the accident files had gathered dust in military archives and the lessons contained in them long forgotten. As air commodores and group captains of that era retired to their golf on the Gold Coast, the lessons of past tragedies retired with them, to wait silently for the next victims.
This article would have finished here except for a chance conversation with a friend now flying PC-12s with the Royal Flying Doctor Service. We met when I was flying Boeings around the Central Pacific many years ago and kept in touch. He had just completed his endorsement on the PC-12 and was impressed with its excellent handling qualities into short dirt strips.The endorsement training carried out at Adelaide included practice turn-backs from 800 feet. By coincidence, his instructor was a former RAAF PC-9 pilot.
The flying skills of RFDS pilots are well documented and there is little doubt the PC-12 has excellent gliding qualities that would serve it well in the event of an engine failure and turn-back. The Winjeel and Vampire could also turn back, providing certain conditions could be met. Those conditions could change by the second and the fact remains that pilots were killed practising a high-risk manoeuvre near the ground. These fatalities would not have occurred had the practice been carried out at a safe altitude that would allow for mishandling.
The Royal Flying Doctor Service operates more than 30 Pilatus PC-12 turboprops, which have excellent handling qualities on the dirt strips found in Australia. This particular example is the 1,500th PC-12 to be built. (Pilatus Aircraft)
Both CASA and ATSB were aware the RAAF and RFDS training syllabus contained turn-back training. The ATSB reply to my letter stating my concerns was that the RFDS considered turn-back training in the PC-12 held no risks and the matter was dismissed. Then an operator in Western Australia introduced practice turn-backs in the Cessna 206 as part of pilot proficiency and recurrent checks on his pilots. He had seen figures in an aviation magazine that purported to prove the manoeuvre could be safely executed above 600 feet. But you had to be quick on the draw, said the article. If CASA were aware of this folly, they looked the other way. Are not practice turn-backs just as risky as night asymmetric practice which is banned by CASA directive?
The purpose of this story is to expose the potential dangers of the practice turn-back manoeuvre. Like mixture cuts on take-off in twin-engine aircraft, turn-back practice can be cynically described as practising bleeding. Over the years there has been no shortage of magazine articles advising that turn-backs can be successful providing height and speed is adequate. They merely state the obvious. It is a manoeuvre that requires skill, an excellent knowledge of the aircraft’s performance capabilities, and more than a little luck to land safely. Faced with the choice between risking a landing among houses or a quick whip-around and cross your fingers, the pilot is in serious trouble either way.
The opening paragraphs of this article described the dangers of practice feathered landings and, following several accidents, early RAAF action to ban the practice. Civil regulatory authorities opted not to go down that path, leaving operational decisions to the pilot, while banning night asymmetric practice. Then both the RAAF and some civil operators introduced turn- back training, despite a history of fatal accidents caused by this manoeuvre. A casual observer could argue with some justification that the RAAF, and now CASA, reveal inconsistency in their approach to training accidents and have failed to learn from past experience.
There is no place for hack-flick-zoom flying near the ground under the guise of training for an emergency, because in the case of a practice turn-back, the final order of events may be similar to that of the unfortunate Winjeel at Point Cook – hack, flick and finally-burn.