Spin Recovery
I think that there is more than a little confusion regarding fully developed deliberately entered spins and accidently entered incipient spins. Most incipient spins in most aircraft can be recovers as Happyjack mentioned - throttle closed and centralise the controls. However, if you don't catch the recovery at the incipient stage, you need to know your aircraft types' spin recovery. There is a standard stall recovery technique - there isn't a standard spin recovery. Of the six types I have regularly spun in my career, all had differences in the recovery.
Well said Dan, and touches on one of my hobby-horses. The RAF, for example, wisely teaches controls central as an initial loss of control / incipient spin recovery. Then IF this didn't work (or of-course, you've deliberately spun the aeroplane) go into the TYPE SPECIFIC spin recovery actions.
Two common lines of thought however annoy me - one is the concept of a common spin set of spin recovery actions for all types, the other is the thinking that in an inadvertent spin one should immediately (thus whilst still presumably in the incipient phase) use a full spin recovery - wasting valuable time and height working out which way the aircraft is spinning, or worse still applying a large rudder input to a stalled aeroplane which is still deciding whether to spin or not.
G
Two common lines of thought however annoy me - one is the concept of a common spin set of spin recovery actions for all types, the other is the thinking that in an inadvertent spin one should immediately (thus whilst still presumably in the incipient phase) use a full spin recovery - wasting valuable time and height working out which way the aircraft is spinning, or worse still applying a large rudder input to a stalled aeroplane which is still deciding whether to spin or not.
G
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Spins, now super-stalls
OK I've learnt thanks to you good people re.spins & inputs !
Now for the big one - ever since reading Don Middleton's ' Test pilots - The History of British Test Flying ' - a truly excellent book - I've been a bit concerned whenever flying in anything with a T tail !
I can understand the desire to get the tailplane away from wing / engine wake & vibration - flutter ( do any modern airliners suffer this ? ) but the top of the fin seems an awful place to put the horizontal stablisers, re. leverage moment let alone deep stall.
I was assured by a Test Pilot that the little PA-44 in I was in wouldn't suffer a super-stall as long as the prop's were blowing across the wings; the obvious next question is ' what if they aren't ?!
Don't get me wrong, I'm not a nervous flyer, just interested in what's going on ! I always try to be useful rather than ' sitting there' - and have alerted a fair few snags over the years -I've been present on plenty of stall tests & seriously daft ultra-low level flying, clandestine photo's for the police etc too.
I do feel for the Flight Test crew of George Errington's Trident, who managed to radio " we're in a superstall now " as they went down - what a horrible last few minutes that must have been...is there any way out of the situation such as asymetric thrust, or are anti-spin chute's or even a rocket to get beyond the thrust/drag curve the only answers ?
With the lack of forward airspeed, even an enterprising soul chucking a large draggy item out of a door might help ?
And no, I'm not thinking along the lines of 'Airport - The Concorde' - possibly the best comedy I've ever seen !
DZ
Now for the big one - ever since reading Don Middleton's ' Test pilots - The History of British Test Flying ' - a truly excellent book - I've been a bit concerned whenever flying in anything with a T tail !
I can understand the desire to get the tailplane away from wing / engine wake & vibration - flutter ( do any modern airliners suffer this ? ) but the top of the fin seems an awful place to put the horizontal stablisers, re. leverage moment let alone deep stall.
I was assured by a Test Pilot that the little PA-44 in I was in wouldn't suffer a super-stall as long as the prop's were blowing across the wings; the obvious next question is ' what if they aren't ?!
Don't get me wrong, I'm not a nervous flyer, just interested in what's going on ! I always try to be useful rather than ' sitting there' - and have alerted a fair few snags over the years -I've been present on plenty of stall tests & seriously daft ultra-low level flying, clandestine photo's for the police etc too.
I do feel for the Flight Test crew of George Errington's Trident, who managed to radio " we're in a superstall now " as they went down - what a horrible last few minutes that must have been...is there any way out of the situation such as asymetric thrust, or are anti-spin chute's or even a rocket to get beyond the thrust/drag curve the only answers ?
With the lack of forward airspeed, even an enterprising soul chucking a large draggy item out of a door might help ?
And no, I'm not thinking along the lines of 'Airport - The Concorde' - possibly the best comedy I've ever seen !
DZ
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Reference recognition of inverted spin versus erect, and direction of rotation:
If not determined by reference to a Turn Indicator, visual recognition of the direction of an erect or inverted spin is best determined by looking to the nose of the aircraft. If one looks "up" or above the nose, the distinction is far less obvious to judge, especially in the the inverted scenario.
Erect or inverted? In an inverted spin, as with any negative manoeuvre, you will experience some, but not necessarily much, negative G. In the Pitts for example, the dangling key ring, or a loose strap end will give you the necessary clue if doubt exists.
All correctly loaded Pitts models (and I have displayed them all) will recover without any drama from any spin - and with even greater ease from the inverted spin. Only one proviso - get all the power off, especially if you have a big, heavy metal prop up front with its gyroscopic's assisting the direction of rotation.
Sooty
If not determined by reference to a Turn Indicator, visual recognition of the direction of an erect or inverted spin is best determined by looking to the nose of the aircraft. If one looks "up" or above the nose, the distinction is far less obvious to judge, especially in the the inverted scenario.
Erect or inverted? In an inverted spin, as with any negative manoeuvre, you will experience some, but not necessarily much, negative G. In the Pitts for example, the dangling key ring, or a loose strap end will give you the necessary clue if doubt exists.
All correctly loaded Pitts models (and I have displayed them all) will recover without any drama from any spin - and with even greater ease from the inverted spin. Only one proviso - get all the power off, especially if you have a big, heavy metal prop up front with its gyroscopic's assisting the direction of rotation.
Sooty
The full spin is defined (within the system I leanred in and later instructed) as when the aerodynamic and gyroscopic forces have reached a state of balance. Prior to this, the spin is in the incipient stage. Recognition of an incipient spin is made easier if you consider that if you have undemanded roll accompanied by buffet, you are spinning. The recovery actions are simple. Centralise the controls and close the throttle. If that doesn't work, you are probably in a fully developed spin and should use your type's recovery technique.
The syllabus we used had the student effecting lots of recoveries from 'unusual positions' (UPs). The student would have to recover the aircraft to level flight with the minimum height loss. These could be spiral dives, stalls, spins or any situation which you don't really want to be in unintentionally. In all cases, remebering that if the aircraft was rolling and you had buffet, it was spinning and should prompt you to centralise/thrust idle. It's a life saver.
One UP entry manoeuvre I often used on students on the Tucano was to start a half cuban pitching up to about 45 degrees. When inverted, realising the attitude was wrong, I pushed as I started the roll applying a bit of rudder. It flick into an inverted spin every time. It's quite disorientating, as it's an inverted spin while the aircraft is still going up. But recognition of the undemanded roll with buffet should prompt the correct recovery.
I got the idea for this UP entry from a student who did it for real on me one day! So it is easy to inadvertantly enter an inverted spin which was a question asked earlier.
The syllabus we used had the student effecting lots of recoveries from 'unusual positions' (UPs). The student would have to recover the aircraft to level flight with the minimum height loss. These could be spiral dives, stalls, spins or any situation which you don't really want to be in unintentionally. In all cases, remebering that if the aircraft was rolling and you had buffet, it was spinning and should prompt you to centralise/thrust idle. It's a life saver.
One UP entry manoeuvre I often used on students on the Tucano was to start a half cuban pitching up to about 45 degrees. When inverted, realising the attitude was wrong, I pushed as I started the roll applying a bit of rudder. It flick into an inverted spin every time. It's quite disorientating, as it's an inverted spin while the aircraft is still going up. But recognition of the undemanded roll with buffet should prompt the correct recovery.
I got the idea for this UP entry from a student who did it for real on me one day! So it is easy to inadvertantly enter an inverted spin which was a question asked earlier.
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My first experience of an inverted spin was in a Pitts - doing a straightforward positive g manoeuvre - a hammerhead (stall turn). Found myself pulling up to and then slightly beyond the vertical, with a bootful of rudder to prevent yaw as the speed decayed. A touch of forward stick to staighten the vertical line, and everything suddenly felt funny - my brain felt as if it were trying to get out of the top of my head. I hadn't met Bill Finagin then, so just did a Beggs-Mueller recovery - power fully off, let go the stick, rudders to neutral, then opposite rudder to recover; pull out of the dive once ASI shows 85 knots...all very simple.
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Quote from Dan Winterland:
From my experience in spin training in relatively violent spinning GA aircraft, could you not possibly accelerate the spin at the midpoint of the incipient stage with the centralizing of the stick position (i.e. from the spin generating input) without first an anti-spin rudder application? While if this does happen, your statement should still get you out, it will have put the aircraft in a worse spin mode and further delay the recovery.
Mind you I have yet to try this general procedure in my normal aircraft, I will at my next opportunity. In my experience with this plane (Morovan Zlin 242L), it is very willing to accelerate with opposite pitch input and centralized rudder. In-fact some acceleration, while minor, can be noticed during the manufacturer prescribed recovery technique, when the stick is brought forward (erect spin), after full opposite rudder has been applied on its way to unstalling and recovering.
The recovery actions are simple. Centralise the controls and close the throttle. If that doesn't work, you are probably in a fully developed spin and should use your type's recovery technique.
Mind you I have yet to try this general procedure in my normal aircraft, I will at my next opportunity. In my experience with this plane (Morovan Zlin 242L), it is very willing to accelerate with opposite pitch input and centralized rudder. In-fact some acceleration, while minor, can be noticed during the manufacturer prescribed recovery technique, when the stick is brought forward (erect spin), after full opposite rudder has been applied on its way to unstalling and recovering.
Quote; "From my experience in spin training in relatively violent spinning GA aircraft, could you not possibly accelerate the spin at the midpoint of the incipient stage with the centralizing of the stick position"
I don't think so. The incipient recovery is all about reducing the angle of attack which should stop the autorotation. Wheras the increase in rotation as the recovery is effected is a characteristic of the fully developed spin of most aircraft. This is because as you move the control column forward, the moments of inertia are reduced and the spin accelerates. I've noticed it on most of the aircraft I've spun (including the Z242) and it is something that was included in the standard CFS style board brief prior to flying the exercise.
Aerobatic aircraft which are designed to be spun a lot have superlative control in this aspect. Even an aircraft such as the Extra 300 with a zero degree incidence symetrical wing will recover from a spin alamost as soon as the contols are centralised. I can't say I remember the spin accelerating as the controls are centralsed - largely because it happens so fast and my brain works slower!
I don't think so. The incipient recovery is all about reducing the angle of attack which should stop the autorotation. Wheras the increase in rotation as the recovery is effected is a characteristic of the fully developed spin of most aircraft. This is because as you move the control column forward, the moments of inertia are reduced and the spin accelerates. I've noticed it on most of the aircraft I've spun (including the Z242) and it is something that was included in the standard CFS style board brief prior to flying the exercise.
Aerobatic aircraft which are designed to be spun a lot have superlative control in this aspect. Even an aircraft such as the Extra 300 with a zero degree incidence symetrical wing will recover from a spin alamost as soon as the contols are centralised. I can't say I remember the spin accelerating as the controls are centralsed - largely because it happens so fast and my brain works slower!
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Spinning modern aircraft ...
Lots of interesting stuff for an old "fast" jet merchant - with a question ... What were, say, the Tornado and Buccaneer like in a spin ??? Or the (BAC) Lightning ??? My ancient mind boggles ...
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Spinning modern aircraft
Jig Peter,
I once experienced a spin in an F4 - very high rotation and oscillation. See attached Youtube video for an idea of what it was like.
http://video.aol.com/video-detail/f-...est/3959631111
X
I once experienced a spin in an F4 - very high rotation and oscillation. See attached Youtube video for an idea of what it was like.
http://video.aol.com/video-detail/f-...est/3959631111
X
F4 spin
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Jag Spinning
Hi Mad (Flt) Scientist. Firstly sorry for the late reply. Yes thats the one where the fuels coming out of the intakes. However, I did eventually get my hands on a copy courtesy of a very kind ex-chief military test pilot.
Thanks.
Thanks.
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Hi Colin,
Sorry, only just got round to reading the spinning thread again and saw the note from you. Yes, we had some good times in Warton, Paris and Toulouse. I still tell the story of the "mockpit cockup meeting" which we held in Toulouse.
I've been in Aus since 1988 after working in Germany on the Flight Control System of the Eurofighter. Worked all over the place in Aus but none of it as interesting as the European Aviation world.
On spinning, for most aircraft (certainly the ones I fly, Pitts, Decathlon and C152) the Muller Beggs technique works fine. My instructor drums in 'power off, centralise the ailerons (ie release the stick), stamp on the wing going forward and then LOWER THE NOSE. The last bit is to take into account the inverted spin situation when you have to pull the stick to lower the nose. However, be careful as Muller Beggs doesn't work on all aircraft.
Cheers, Clive (current, for one more month, Queensland Aerobatic Champion for 2008/09!)
Sorry, only just got round to reading the spinning thread again and saw the note from you. Yes, we had some good times in Warton, Paris and Toulouse. I still tell the story of the "mockpit cockup meeting" which we held in Toulouse.
I've been in Aus since 1988 after working in Germany on the Flight Control System of the Eurofighter. Worked all over the place in Aus but none of it as interesting as the European Aviation world.
On spinning, for most aircraft (certainly the ones I fly, Pitts, Decathlon and C152) the Muller Beggs technique works fine. My instructor drums in 'power off, centralise the ailerons (ie release the stick), stamp on the wing going forward and then LOWER THE NOSE. The last bit is to take into account the inverted spin situation when you have to pull the stick to lower the nose. However, be careful as Muller Beggs doesn't work on all aircraft.
Cheers, Clive (current, for one more month, Queensland Aerobatic Champion for 2008/09!)
Sludge, your statement that Beggs-Mueller works for the C152 is interesting as Beggs' articles only mention the C150 not the C152 and he reported that it did not work for some C150 spin modes.
Also, he only "tested" the 180 hp variant of the Decathlon and could not get it into an inverted flat spin. I wonder if that was because he was solo so had a fwd cg only - just my guess despite his comment that he "thoroughly tested" it. Still he does gaurantee the method, whatever that means. A 150 hp F/P Decathlon two up has a cg very much further aft.
PS - a bunch of Victorians will be trying to take the trophy next month.
Also, he only "tested" the 180 hp variant of the Decathlon and could not get it into an inverted flat spin. I wonder if that was because he was solo so had a fwd cg only - just my guess despite his comment that he "thoroughly tested" it. Still he does gaurantee the method, whatever that means. A 150 hp F/P Decathlon two up has a cg very much further aft.
PS - a bunch of Victorians will be trying to take the trophy next month.
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At least one fatal accident in a Pitts was believed to be caused by the pilot not recognising that it had gone inverted.
I tried to abort a stall turn (as I was about to go into a solid cloud base) by trying to kick the Pitts S2A earlier than normal which didn't work as I will still going up vertically in a huge sideslip and then pulled the stick back to make the aircraft just snap into a normal spin to lose height.
To my surprise the aircraft fell on its back in a flat attitude and stayed there which is wasn't what I expected and as I had about 5000ft so I figured it was best to let the aircraft stabilise and then figure out what was going on.
The airspeed started to increase so I figured this was more of an inverted spiral dive than a spin so I tried to roll out of it in a stick neutral position and then the Pitts flipped into a nose down spin. I lost about 3000ft during the whole exercise.
I spoke to a former aerobatic champ (Chris Sperou - Australian Unlimited Champ) about what happened and he said the nose not dropping through and staying flat was symptomatic of not having the power FULLY back it idle , he said even a few hundred rpm off idle can do it with the right combination of factors .
I went out and did inverted spin training after that (with a retired military test pilot) and would highly recommend inverted spin training to anyone flying some of the more capable aerobatic aircraft.
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Hunter spin
I seem to recall, on the / a Hunter, a white mark on the panel one pushed the stick towards and to one side for spin training.
Snag is, not having done it myself, I can't remember if it was for recovery or to promote a spin, which may be the sort of detail one rather cares about at the time.
It was quite possibly the ETPS Hunter, and sounds a bit like it would promote a spin in the right conditions.
If a type should have recovery characteristics requiring something like ' push it this way' ( most of the time, I know ) rather than ' leave it alone ' it would seem worth marking in such a manner for disorientated inexperienced pilots who may well have trouble remembering details from the notes if flustered ?...
DZ
Snag is, not having done it myself, I can't remember if it was for recovery or to promote a spin, which may be the sort of detail one rather cares about at the time.
It was quite possibly the ETPS Hunter, and sounds a bit like it would promote a spin in the right conditions.
If a type should have recovery characteristics requiring something like ' push it this way' ( most of the time, I know ) rather than ' leave it alone ' it would seem worth marking in such a manner for disorientated inexperienced pilots who may well have trouble remembering details from the notes if flustered ?...
DZ
To add to my earlier note ... owner of 150 hp F/P Decathlon says that two up in an inverted spin the Beggs-Mueller technique will not work - stick remains fully forward.
Do a Hover - it avoids G
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The white spot on the Hunter was to help you push the stick forward with the ailerons central. It was intended to help safe recoveries because holding even a little inadvertent out-spin aileron could prevent recovery in many cases.
Other point to make about ETPS hunter spinning was that there was a telemetry link with a pilot on ground monitoring and assisting where necessary , i.e calling engine flamed out etc. Whilst working on the F6 in 1981 , launched the jet and went over to telemetry with safety pilot to watch,very interesting ! Especially the inverted spinning as for them it appeared so routine !! Recall blue peter presenter going for a spin with mike brookes , presenter did not enjoy himself , audio had to be dubbed on after !!!
"Recall blue peter presenter going for a spin with mike brookes , presenter did not enjoy himself"
I'll never forget seeing J. Clarkeson esq spinning in the Hunter with Rees Williams many years back - classic
I'll never forget seeing J. Clarkeson esq spinning in the Hunter with Rees Williams many years back - classic