Pt. Cook Fatal Accident ~1990
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It was VH-SGC. I did a lot of hours in the little beast during 1987-8 including a precautionary landing on an ag strip near Yass with a suspected engine problem on the way back to Point Cook after the Canberra Air Pageant on 13 Mar 88.
I heard that Birko's accident was a slow response to an insidious simulated engine failure. I also recollect that it happened very close to 1 December.
I heard that Birko's accident was a slow response to an insidious simulated engine failure. I also recollect that it happened very close to 1 December.
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I don't think turn back per se is the key element of this particular accident though i wouldn't be up for one in a tigershmit at any time, especially from 300' if that is correct. Having said that a practice TB is different from what any of us may do in a real engine failure situation. landing into a headwind in a tiger is a low speed affair and highly survivable regardless of the location or landing area
There are a couple of other aspects of this (or similar) accidents.
If the take off was flown from a glide approach (which I was told it was) the trim would be FNU, applying T/O power without a reset would promote a higher attitude and lower speed than usual, and even slightly lower is an issue in a low energy, high drag vehicle.
PEFATO at a low height from a low(isher) speed would be problematic unless nose lowered , immediately and dramatically, any hesitation would bleed speed and existing energy rapidly. no slats - little stall waring indication. rudder bias (fixed) would tend to yaw the aircraft with compensating opposite aileron, which stalls lower wing and pilot impulse, at nominal altitude, MAY be to not be sufficiently aggressive in the push down, and to try to maintain the wings level with aileron against rudder in what COULD be an even slightly cross controlled config.
A turn back may not have been the intention in this particular instance, regardless of what was briefed prior to flight, but could have looked like it from the ground. without a CVR impossible to say.
So: low and decaying speed, proximity of ground, falling wing, nose up trim, spring bias (against non-existant power) and you MIGHT POSSIBLY be in a very bad place that, if not immediately recognized and rectified MAY enter a spin with insufficient height for recovery. the vital need to push hard forward can be very difficult when the aircraft nose is falling (region of reversed command) already and ground is approaching and ground rush impluse is to pull.
These are possibilities, not facts, but could fit the frame.
I knew the IP, he was a top bloke, I and was at a course at Richmond the day it happened. I remember the hearing of it in a lecture room and all the pilots on the course were dumb struck. We were just discussing the elevated risk involved with un-briefed procedures and spontaneous demonstrations of flight characteristics or handling, so there was much ongoing, and i add relatively uninformed, speculation regarding the circumstances that may have surrounded such an event. Three of us on course had reasonable Tiger time.
Very many considerations surround this accident which occurred on a nice day when a couple of blokes were having a well intentioned flog around the paddock to tick some boxes in a liesurely and gentlemanly sort of way. Not in any way saying that this was any ones fault etc etc.. just that we should all have a good think and brief before any type of exercise however innocuous it may seem at first glance.
Lessons can be learned
HD
There are a couple of other aspects of this (or similar) accidents.
If the take off was flown from a glide approach (which I was told it was) the trim would be FNU, applying T/O power without a reset would promote a higher attitude and lower speed than usual, and even slightly lower is an issue in a low energy, high drag vehicle.
PEFATO at a low height from a low(isher) speed would be problematic unless nose lowered , immediately and dramatically, any hesitation would bleed speed and existing energy rapidly. no slats - little stall waring indication. rudder bias (fixed) would tend to yaw the aircraft with compensating opposite aileron, which stalls lower wing and pilot impulse, at nominal altitude, MAY be to not be sufficiently aggressive in the push down, and to try to maintain the wings level with aileron against rudder in what COULD be an even slightly cross controlled config.
A turn back may not have been the intention in this particular instance, regardless of what was briefed prior to flight, but could have looked like it from the ground. without a CVR impossible to say.
So: low and decaying speed, proximity of ground, falling wing, nose up trim, spring bias (against non-existant power) and you MIGHT POSSIBLY be in a very bad place that, if not immediately recognized and rectified MAY enter a spin with insufficient height for recovery. the vital need to push hard forward can be very difficult when the aircraft nose is falling (region of reversed command) already and ground is approaching and ground rush impluse is to pull.
These are possibilities, not facts, but could fit the frame.
I knew the IP, he was a top bloke, I and was at a course at Richmond the day it happened. I remember the hearing of it in a lecture room and all the pilots on the course were dumb struck. We were just discussing the elevated risk involved with un-briefed procedures and spontaneous demonstrations of flight characteristics or handling, so there was much ongoing, and i add relatively uninformed, speculation regarding the circumstances that may have surrounded such an event. Three of us on course had reasonable Tiger time.
Very many considerations surround this accident which occurred on a nice day when a couple of blokes were having a well intentioned flog around the paddock to tick some boxes in a liesurely and gentlemanly sort of way. Not in any way saying that this was any ones fault etc etc.. just that we should all have a good think and brief before any type of exercise however innocuous it may seem at first glance.
Lessons can be learned
HD
A turn back may not have been the intention in this particular instance, regardless of what was briefed prior to flight, but could have looked like it from the ground. without a CVR impossible to say.
The Winjeel accident at Point Cook as described earlier was a similar event. At the Court of Inquiry we could never prove that the intention was a turn back or whether in fact the student attempted a turn through 90 degrees (approx) to aim at a nearby beach. We did know from witness statements that the initial turn after the instructor had called he was doing a simulated engine failure, was made quite nose high and the aircraft went into the incipient spin from that position.
Some years ago I learned that a senior pilot of the RFDS and in charge of endorsements to the PC12 was reaching turn banks on the PC12. Turned out he was a former RAAF instructor. The theory was the PC12 had excellent gliding characteristics with its prop feathered and that it could safely do a turn back after take off once a certain minimum height was reached.
I know little of the PC 12 but shook my head in disbelief that after accidents that had ocurred over the years with pilots practicing turn backs and getting killed, the lessons of the past were being ignored. I dropped a line to CASA who never even bothered to reply. Ops normal....
That's the thing though, Centaurus, it may be appropriate for some types if carefully thought through, briefed and practiced, because of the tradeoff between low glide performance/good chance of pulling off a safe paddock landing on the one hand, or good glide performance/good chance of hurting or killing yourself landing off the airfield on the other.
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The address is of a document about safe ETAFO procedures and why there are many good reasons to Not turn Back
http://www.gofir.com/aviation_accident_prevention_program/docs/pdf/single_engine_failure.pdf
However there are a couple of issues I would take with it. The figure 1 shows how turn radius affects the distance required for those who are not familiar with this procedure, which I hasten to add I would only advocate as a method of last resource, when you are faced with certain death ahead and maybe in the damned if you do and damned if you don’t situation:
Figure 1- Although doubling turn rate halves turn radius when attempting to turn
back to the runway, stalling speed increases dramatically.
The author then posits that the following stall speed increases would apply in such a situation which I do not agree with. Whenever teaching (or mainly demonstrating) such a procedure I strongly advocate steep bank angle and sufficient nose down to ensure a well safe speed (quite high descent rate). This will result in a significantly lower loading than the table below as you are not conducting a LEVEL turn, at least not in any (failed) single engine plane that I have ever flown and a much better view.
Bank Angle Stall Speed Increase (%)
0 deg. 49 knots 0%
35 deg. 53 knots 8%
45 deg. 59 knots 20%
60 deg. 71 knots 43%
75 deg. 97 knots 97%
Table 1-Typical chart for a four-seat single shows relation of stall speed to bank
angle.
This high descent rate is what determines the possibility of executing a turn back and the altitude required for such a procedure, when done correctly and the planets are in line. If you need about 40 – 50 seconds to lower the nose and execute the 120 degrees or so of turn required, with an average descent rate of about 1000 fpm (normal glide 600fpm) then you will be needing about 1000 feet as a practical minimum as you will have only about 1 minute from EF to LDG so this si definately not a low level option.
Turn back has so many other considerations, singular and in combination, such as terrain, structures, wind strength and direction, micro climate wind, runway /field layout/shape, approach obstructions etc. this is not something to do as a spur of the moment option, if it was not included at the pre take off brief it is most likely not a viable option to be sorting out whilst fumbling with engine and fuel levers,, flaps, trim and all that stuff.
It can work, BUT……It is a very risky alternative to the traditional option of: land ahead (45 either side) , into wind, present the vehicle at minimum energy at touchdown, it is not so important WHERE you land, rather, HOW you land, if you are in control at touch down you have quite a good chance of survival usually…….and with any tricycle aircraft with a fixed link nosewheel steering, remove feet from pedals immediately before touch down.
http://www.gofir.com/aviation_accident_prevention_program/docs/pdf/single_engine_failure.pdf
However there are a couple of issues I would take with it. The figure 1 shows how turn radius affects the distance required for those who are not familiar with this procedure, which I hasten to add I would only advocate as a method of last resource, when you are faced with certain death ahead and maybe in the damned if you do and damned if you don’t situation:
Figure 1- Although doubling turn rate halves turn radius when attempting to turn
back to the runway, stalling speed increases dramatically.
The author then posits that the following stall speed increases would apply in such a situation which I do not agree with. Whenever teaching (or mainly demonstrating) such a procedure I strongly advocate steep bank angle and sufficient nose down to ensure a well safe speed (quite high descent rate). This will result in a significantly lower loading than the table below as you are not conducting a LEVEL turn, at least not in any (failed) single engine plane that I have ever flown and a much better view.
Bank Angle Stall Speed Increase (%)
0 deg. 49 knots 0%
35 deg. 53 knots 8%
45 deg. 59 knots 20%
60 deg. 71 knots 43%
75 deg. 97 knots 97%
Table 1-Typical chart for a four-seat single shows relation of stall speed to bank
angle.
This high descent rate is what determines the possibility of executing a turn back and the altitude required for such a procedure, when done correctly and the planets are in line. If you need about 40 – 50 seconds to lower the nose and execute the 120 degrees or so of turn required, with an average descent rate of about 1000 fpm (normal glide 600fpm) then you will be needing about 1000 feet as a practical minimum as you will have only about 1 minute from EF to LDG so this si definately not a low level option.
Turn back has so many other considerations, singular and in combination, such as terrain, structures, wind strength and direction, micro climate wind, runway /field layout/shape, approach obstructions etc. this is not something to do as a spur of the moment option, if it was not included at the pre take off brief it is most likely not a viable option to be sorting out whilst fumbling with engine and fuel levers,, flaps, trim and all that stuff.
It can work, BUT……It is a very risky alternative to the traditional option of: land ahead (45 either side) , into wind, present the vehicle at minimum energy at touchdown, it is not so important WHERE you land, rather, HOW you land, if you are in control at touch down you have quite a good chance of survival usually…….and with any tricycle aircraft with a fixed link nosewheel steering, remove feet from pedals immediately before touch down.
