Flight Safety Report: Remember Your Training - a fatal accident on take-off & Supervision, The Missing Ingredient?

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The overloaded aircraft would have had a wings-level +1g stalling speed of 72 knots. The best angle of climb speed was 75 knots. As can be seen from the table above, the aircraft would have stalled at 75 knots with just 22.8 degrees of bank applied. It is very likely that the Commander 114TC involved in the above accident stalled during the attempted turn back to the airport. The pilot apparently had almost regained control at very low level but then stalled and spun with fatal results.


Many of the facts regarding this accident are taken from AAIB Field Investigation EW/C2001/6/7 which source is gratefully acknowledged.

 

Supervision — The Missing Ingredient?

Accidents and incidents are seldom due to a single cause. They are the result of a chain of events that combine to result in an accident or incident. Many years of accident investigations, and of the application of lessons learnt from accidents, have reduced flying accident rates quite dramatically but one root cause has defied all efforts to eliminate it. That root cause is human error.

 

Human error comes in many guises and is as varied as human nature itself. It is probably an unachievable aim to hope to eliminate human error, but we can attack various aspects of human error and thus reduce the overall size of the problem.
      I believe that many, if not most, accidents and incidents suffered by private pilots in recreational flying have
lack of skilled supervision as a root cause.
      Supervision is readily available to student pilots during their
ab initio flying training. The quality of this supervision depends upon the quality of their flying instructors and on the standards set by the training organisation where the student is studying the art of aviation. Unfortunately, there is no guarantee that every student pilot will have dedicated, highly motivated and closely supervised flying instruction because supervision of flying instructors is not regulated to a common standard. In my experience, the quality of instruction tends to reflect the standards set by the local CFI. We are faced with the old conundrum, “Who supervises the supervisors?”

 

 

The Military Exemplar
I accept that many private pilots, and their instructors, will react with violent disagreement to the suggestion that we can learn something from the military system. Perhaps a comparison of the accident statistics of military flying and those of recreational flying will give some pause for thought. Yes, I know that military pilots go through a rigorous selection where the unsuitable are weeded out; I know that each military pilot’s training costs n millions of cash; I recognise the riposte from recreational pilots that if they’d wanted to be like military pilots they would have joined the Forces. But one thing that military pilots have in their favour is constant and highly-skilled supervision of all aspects of their flying.
      Somebody makes sure they have been adequately trained before they are required to perform any task. Somebody provides them with the best available kit for comfort and survival. Many highly trained, skilled and closely supervised men and women make sure their aircraft is maintained to the highest standards and is meticulously prepared for each flight. Somebody makes sure they are in good health and fit to fly by regular medical checks and by training in aviation medicine. There is even somebody whose task is to ensure that they are properly fed with a correct diet.
      A private pilot has to take personal responsibility for these and many other tasks if safety is to be ensured. Yet the only selection procedure involved if one decides to become a private pilot is the ability to sign valid cheques for large sums of money. The medical standards are not above normal fitness levels. There are no educational standards, other than an ability to pass some examinations during training. Once private pilots have got their PPL they are free to go about their flying without any further supervision – other than the periodic check flight now required by some authorities. There is not a pilot in the world who will not develop bad habits as time goes by.

 

 

Examine Your Thought Processes Before You Fly
- Perhaps nobody else flies your aircraft. It was perfectly alright when you last flew it so nothing can have changed while it has been sitting on the ground. So it doesn’t need a detailed and searching pre-flight. WRONG.
- You have flown out of this strip dozens of times so you don’t need a performance calculation. WRONG.
- You know the route like the back of your hand so you don’t need a flight plan. WRONG.
- The weather has been settled for days so you don’t need a forecast. WRONG.
- Just bung that extra bag in the back; it doesn’t look very heavy. WRONG.
- It’ll only take an hour or so to get there so there’s plenty of fuel on board. WRONG.
- Must get that dicky radio looked at sometime soon. WRONG.
- But you’d never do any of those silly things and this article doesn’t apply to you. WRONG.

If you are totally honest with yourself you have probably done at least one of the things mentioned above, or something pretty similar. If not, you probably will at some time in the future.
      Why do pilots do these things? Not because they want to kill themselves and their passengers. Probably because they got away with it once and therefore it doesn’t matter any more. Pilots, being human, gradually develop bad habits because they are not being supervised and are not supervising themselves. How long is it since you had a real check flight with an instructor? Not with a mate, but with someone who will demand reasonable standards and tell you so before and after the flight?

 

 

Bad Habits are Habit Forming
Let’s look back at the support and supervision enjoyed by the military pilot and compare your environment. Military pilots undergo frequent checks on all aspects of their flying and operational skills. They are surrounded by equally skilled pilots who will immediately make them aware of the slightest drop in their standards. Who taught you to do a forced landing after engine failure? How long ago? How often do you practice? Who last checked your technique and ability? What is a constant aspect approach? How does ground effect affect you take-off performance? What does pressure altitude have to do with performance? When did you last check the tyre pressures?
      Nobody can maintain a constantly high standard of piloting ability over a long period of time without being examined by an instructor. Why do airline pilots have to spend long hours in simulators and have regular checks in the air? Because everyone develops bad habits and loses the sharp edge of their ability.
      A very recent landing accident to a Boeing 757 was caused by the commander having recently developed a habit of applying full nose-down elevator after mainwheel touchdown in the belief that this technique would improve braking and control effectiveness in wet or slippery conditions.  The Air Accidents Investigation Branch noted  “an intrinsic feature of such a habit is the possibility of execution without conscious monitoring.” The pilot concerned had over 11,000 hours with 5,000 hours on type. Everyone can, and will, develop bad habits.
      How about arranging to spend a few hours with a ground instructor revising your understanding of your aircraft’s systems and performance data? How about doing a few practice flight plans – under supervision? How about a few practice performance calculations – under supervision?
      Why not go the whole hog and have an hour in the air with an instructor while you revise whatever aspect of your flying that most needs revision?
Only two kinds of pilots require supervised revision of their skills; those who fly irregularly and those who fly regularly.
      Supervision will improve your flying. Supervision will sharpen your piloting ability. Supervision will remind you to maintain your standards – and to book some more supervision.
      Good luck and happy flying.

 

 

 

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Remember Your Training

All student pilots should be taught how to calculate the take-off performance of their aircraft and encouraged to complete this calculation before every take-off. All student pilots are taught that the angle of bank affects the stalling speed of an aircraft. They are also taught that the weight of an aircraft affects the stalling speed of an aircraft. A fatal accident demonstrates why we should always remember our training.

 

The aircraft involved was a Commander 114TC powered by a Lycoming T10-540-AG1A six cylinder engine. The aircraft was three years old and had some 250 hours total time on both the engine and airframe. It was been flown by two pilots. The owner had a UK PPL and an American Instrument Rating with a total of 315 hours, of which about 250 hours were on type. The other pilot held a US CPL with Instrument Rating and was a qualified Flight Instructor with a total of 1,002 hours. The owner and the American pilot planned to fly the aircraft together around the world.
      The Commander 114TC had a basic weight of 2,429 lb and a Maximum Take-off Weight (MTOW) of 3,305 lb. The wings level stalling speed at MTOW and zero degrees flap was 68 kt. The best rate of climb speed is 100 kt and the best angle of climb speed is 75 kt.
      The accident aircraft was overloaded at takeoff at a weight of 3,535 lb, some 230 lb above MTOW. There may have been some reduction in the power output from the engine during the take-off run and subsequent attempt to climb away because the ground roll was considerably longer than normal. The Take-off Run Available was 1,650 metres with a threshold elevation of 44 ft amsl and a slight downslope into a ten knot headwind component. The ground rises to 207 ft amsl some 1,750 metres beyond the end of the runway. Witnesses recorded that the aircraft ground roll was between 1,100 metres and 1,200 metres and its angle of climb was unusually shallow. The expected ground roll in the known conditions would be 480 metres, with a distance to 50 feet of 840 metres. The pilot made the following radio call: “We have an emergency, we’re not climbing, I don’t know why, we’d like to come back and land.” The controller immediately replied “You can make a left or right turn position downwind right.” The owner acknowledged and the controller saw the aircraft bank to the right at between 300 and 600 feet agl. It seemed to sideslip and disappeared behind buildings. There was black smoke from the area and the Airport Fire Service was alerted.
      One witness saw the aircraft when it had almost completed its turn back towards the airport and was at a height of 50 to 100 feet above ground with the nose high and the rear of the aircraft “moving from side to side”. It cleared some trees by a few feet, pitched up, rolled to the right and dived almost vertically into the ground. Both occupants died on impact.
      Examination of the aircraft engine revealed evidence of rich running of the No.2 cylinder but this would not have caused a gross loss in power. The additional weight above MTOW and the fact that the air conditioning system was on during take-off would have increased the take-off distances by some 15%, giving a ground roll of 552 metres and a distance to 50 feet of 966 metres – still considerably less than the distances observed. General Aviation Safety Leaflet 7B deals with aircraft performance and recommends that pilots work out a decision point for all take-offs so that the pilot can stop the aircraft
‘in the event of an engine or other malfunctions e.g. low engine rpm, loss of ASI, lack of acceleration or dragging brakes’. The advice is ‘Do NOT mentally programme yourself in a GO-mode to the exclusion of all else.’ The evidence indicates that a ‘stop’ decision should have been made before the aircraft became airborne.
      It may be valuable to remind pilots of the relationship between weight, angles of bank and stalling speed.

 


Weight
Weight and Lift are equal in level flight so any increase in weight will demand an increase in lift. This means that your aircraft will stall at a higher IAS as the weight is increased. A rule of thumb is that the percentage increase in stalling speed is half the percentage increase in weight. The Commander 114TC will stall at 68 kt in level flight at 3,305 lb MTOW. The accident aircraft was overloaded to 3,535 lb, giving a new stalling speed approaching 72 kt. The best angle of climb speed was 75 kt.      [TOP]


Angle of Bank
The stalling speed in a turn increases as the square root of the load factor. The load factor is proportional to the secant of the angle of bank. (The secant of an angle is 1 over the cosine). The table below shows the effect on the stalling speed of different applied angles of bank when the basic stalling speed is 72 kt.

Angle of Bank deg

Load Factor n

Sq. Root n

Stalling Speed Kt

0

1.000

1.000

72.0

10

1.015

1.007

72.5

20

1.064

1.031

74.3

30

1.154

1.074

77.3

40

1.305

1.142

82.3

45

1.414

1.189

85.6

50

1.555

1.247

89.8

60

2.000

1.414

101.8