Spin recovery using power
Not so N, but still FG
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Spin recovery using power
Calling all instructors, current and former Brendaflyers, and assorted aeros fiends.
Re: Alan Cassidy's piece in the latest edition of "Pilot" on spin recovery.
Discuss...
Re: Alan Cassidy's piece in the latest edition of "Pilot" on spin recovery.
Discuss...
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Was reading it this morning and found it very interesting indeed particularly his comment that he had never found flown a modern aeroplane where the added benefit of increased rudder authority was outweighed by adverse gyroscopic effects...
In the Yak 52, the power-on flat spin is recovered (using the method taught by Russian instructors) using a series of specific inputs commencing with retarding the throttle. I have separately been told that power-on will recover the flat spin faster but that if centralising the controls from the "recovery position" is not done at precisely the correct time, the flick into an inverted spin is much faster than it might otherwise be.
Given some of the accidents that have sadly befallen flat-spinning Yaks, this change in technique is not one I'd debut solo. But the theory as to why power-on might be of benefit seems to my comparatively uneducated view to have validity.
What, by the way, is your view FNG?
In the Yak 52, the power-on flat spin is recovered (using the method taught by Russian instructors) using a series of specific inputs commencing with retarding the throttle. I have separately been told that power-on will recover the flat spin faster but that if centralising the controls from the "recovery position" is not done at precisely the correct time, the flick into an inverted spin is much faster than it might otherwise be.
Given some of the accidents that have sadly befallen flat-spinning Yaks, this change in technique is not one I'd debut solo. But the theory as to why power-on might be of benefit seems to my comparatively uneducated view to have validity.
What, by the way, is your view FNG?
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I am sure that I am comparatively much more uneducated than you, Southern Cross. I thought the article well done, as it stated the author's position very clearly and succinctly, knowing that it will probably attract strong comment and perhaps even censure. As to the suggested technique, like you I would not set out to investigate it without a highly experienced aerobatic instructor sitting next to me (a bit tricky in a Yak 50, I appreciate). Of course, ordinarily when we go spinning we find that the aircraft recovers quickly with the standard inputs. If I was ever in the position where the aircraft failed to respond, Alan's article might at the least prompt me to try one more thing before jumping out or, as the case might be, making a hole somewhere in Berkshire.
Presumably pilots testing the Bulldog and indeed any type must experiment with recoveries power on, off, in between, wearing a green hat, wearing a blue hat, wearing no hat, shouting "caramba" in Polish etc etc. I can recall seeing Bulldog spinning debated at length on pprune on more than one occasion, but can't remember if anyone ever discussed the ideas canvassed in the article.
I shall be interested to talk it over with my co-owners, both of whom are QFIs, and some of the other aeros specialists at Waltham.
I've posted a cross reference to this in the Instructor's forum in the hope that some of the regulars there will let us have their thoughts on the subject, or, at the least, entertain us by re-telling the amusing tale of the "Bulldog Cabriolet".
[ 15 February 2002: Message edited by: FNG ]</p>
Presumably pilots testing the Bulldog and indeed any type must experiment with recoveries power on, off, in between, wearing a green hat, wearing a blue hat, wearing no hat, shouting "caramba" in Polish etc etc. I can recall seeing Bulldog spinning debated at length on pprune on more than one occasion, but can't remember if anyone ever discussed the ideas canvassed in the article.
I shall be interested to talk it over with my co-owners, both of whom are QFIs, and some of the other aeros specialists at Waltham.
I've posted a cross reference to this in the Instructor's forum in the hope that some of the regulars there will let us have their thoughts on the subject, or, at the least, entertain us by re-telling the amusing tale of the "Bulldog Cabriolet".
[ 15 February 2002: Message edited by: FNG ]</p>
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Having had a couple of lessons with Alan Cassidy and being hugely entertained (and not a little impressed) by his accelerated flat spin in the Pitts, where you feel the g in your back rather than your seat, I can claim but a fraction of his knowledge and experience in the field. I have often thought that if an aircraft I was spinning failed to recover and I had the height I would try a blast of throttle to energise the rudder (never tried it yet though). . .The problem arises when you have to teach a generic spin recovery technique to ab-initio students, who can virtually crap themselves when they experience their first one. As far as I am aware the technique taught to RAF students is valid for every type they are likely to spin during their service career (although I stand to be corrected on that) so it makes sense to teach that rather than a technique which could be type-specific and may require more thought than that required to carry out the automatic response involved in the standard recovery as currently taught.. .Having said all that I'd love to try the techniques mentioned and will do when I can get someone who knows more about it to sit beside me.
[ 16 February 2002: Message edited by: DB6 ]</p>
[ 16 February 2002: Message edited by: DB6 ]</p>
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The RAF do not have a single spin recovery technique. The spin recovery actions for each type are in the Flight Manual (POH) for that type and have been worked out by the good folks at Boscombe Down. Obviously some of these actions will be the same for 2 different aircraft (but compare actions in the Bulldog Flt Manual to those in, say, the Phantom). If you go for a technique not in the POH then you are entering uncharted territory and run the risk of making things worse.
Stan is absolutely right, I was responsible for a few of those RAF operators manual recoveries during my time at BDN, and a few more since on civil aircraft.
There is not, never has been, and never will be, a common spin recovery to all types. Any QFI who teaches initial spinning, to any method than that given in the POH for that type should, in my opinion, be put against a wall and shot. Slowly !. The correct method is that in the POH, students should know that is where it is, that as pilot in command of any type they should be familiar with it, and that it will not be the same on each type.
Yes, most types will respond to one of two or three standard recoveries, the most well known being close the throttle, put the stick in the middle, apply opposite rudder to the turn, and wait for the recovery.
There is another view of-course, which is that an experienced aerobatic pilot, in a type that they know well, can use different series of actions to give different responses. There is nothing wrong with this, initially at a safe height, and wearing a parachute. But, this sort of thing has absolutely no place in initial spin training.
One other thing, use of power deliberately during a spin puts HUGE cyclic loads on the crankshaft and hub and significantly increases the risk of a subsequent engine failure.
G
There is not, never has been, and never will be, a common spin recovery to all types. Any QFI who teaches initial spinning, to any method than that given in the POH for that type should, in my opinion, be put against a wall and shot. Slowly !. The correct method is that in the POH, students should know that is where it is, that as pilot in command of any type they should be familiar with it, and that it will not be the same on each type.
Yes, most types will respond to one of two or three standard recoveries, the most well known being close the throttle, put the stick in the middle, apply opposite rudder to the turn, and wait for the recovery.
There is another view of-course, which is that an experienced aerobatic pilot, in a type that they know well, can use different series of actions to give different responses. There is nothing wrong with this, initially at a safe height, and wearing a parachute. But, this sort of thing has absolutely no place in initial spin training.
One other thing, use of power deliberately during a spin puts HUGE cyclic loads on the crankshaft and hub and significantly increases the risk of a subsequent engine failure.
G
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I went to Russia in 1993 to collect the first ever Yak-55 export. While there I flew with Sergei Tatevosov in a Yak-52. We did several repeats of a power-on upright flat spin from a stall turn (right rudder) entry. The rotation, with right foot, left aileron and about half forward elevator is very frisbee-like.
The recovery taught me, and which I have since used successfully on Yak-55, and all 3 types of Sukhoi is to maintain power, change feet, then move the stick back, right and then forward. The stop is very sharp and takes about half a turn.
This has been repeated several times in the UK in different Yak-52s, with identical results.
The mirror image technique works on American-engined aircraft. I have considerable experience of this flat spin recovery at display heights in Pitts types, CAP-232 and -222. In all these instances, in-spin aileron is quoted in the POH for flat spin recovery. It all just works much better with power on.
The recovery taught me, and which I have since used successfully on Yak-55, and all 3 types of Sukhoi is to maintain power, change feet, then move the stick back, right and then forward. The stop is very sharp and takes about half a turn.
This has been repeated several times in the UK in different Yak-52s, with identical results.
The mirror image technique works on American-engined aircraft. I have considerable experience of this flat spin recovery at display heights in Pitts types, CAP-232 and -222. In all these instances, in-spin aileron is quoted in the POH for flat spin recovery. It all just works much better with power on.
Hi Al.. .Good to see you on the network.. .With regard to your article,as you so rightly say, it was bound to be controversial.. .My view is that you have spent an awful lot of time experimenting, making the mistakes and sorting them out successfully.. .Therefore I am quite prepared to listen very carefully to a different viewpoint, give it the benefit of the doubt and, as I teach most of my time, probably find a bit of height one day and try it for myself. . .Maybe you've got something. <img src="wink.gif" border="0"> <img src="wink.gif" border="0">
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Hi Mr Cassidy,
I haven't seen the article, so forgive my dumb questions:
Is this spin recovery technique aimed at achieving a crisp exit to a competition spin? Is it intended as a general spin recovery for intentional spins? Is it intended as a general spin recovery for all spins, whether competition, intentional or not?
(Let's skip all the usual, tedious caveats about very different spin recovery techniques being required for Jet Provosts, Sopwith Camels, Airbuses and helicopters, ta muchly.)
TW
I haven't seen the article, so forgive my dumb questions:
Is this spin recovery technique aimed at achieving a crisp exit to a competition spin? Is it intended as a general spin recovery for intentional spins? Is it intended as a general spin recovery for all spins, whether competition, intentional or not?
(Let's skip all the usual, tedious caveats about very different spin recovery techniques being required for Jet Provosts, Sopwith Camels, Airbuses and helicopters, ta muchly.)
TW
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Dear Tricky, as the weather is pleasant today, Mr Cassidy is probably off flying in one of his special up side downy machines, so let me tell you a bit about the article, which is well worth a read. It appears to be be aimed at average GA pilots, and it has specific relevance for those who have stumped up the loot to civilianise the well flogged Dogs recently let out to play by HMG. I plan to go off aerobatting in a Dog this afternoon and hope not to have need of Mr C's technique, especially as the canine in question comes without parachutes.
PS: your name has been taken in vain here recently, see posts by one Flyer Boy, passim, and either defend your honour, or fess up.
PS: your name has been taken in vain here recently, see posts by one Flyer Boy, passim, and either defend your honour, or fess up.
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Hi folks. .. .Somebody just sent me Alan Cassidy’s original article. Sorry to come so late to the party.. .. .I thought it very well written, very well argued and since I have no experience on the aeroplanes Alan was writing about I can only say well done – he convinced me there has to be a case to answer. I shall be interested to see how the experienced guys in these sorts of aircraft respond. . .. .My only thoughts of caution are that inexperienced pilots with little or no formal (and recent) spin training who are unlucky enough to find themselves unexpectedly in what they think is a spin, are actually very poorly placed to call to mind any recovery actions, let alone apply them properly. . .. .Because of that I feel that if their aircraft does not recover promptly then the most likely reason is that they had not taken the standard recovery properly – hence the emphasis to check it again rather than try other things. . .. .Experienced pilots may well use their experience to try all sorts of things when up against a problem (and I am not only thinking spinning here) What Michael Schumacher might do to sort out a family car in the wet is one thing but would you brief your Aunty to try the same? The most you can reasonably hope for is that she remembers you told her to push very hard on the brake to invoke the ABS and also winds the wheel instinctively. But don’t be surprised if she just hits the clutch and screams.. .. .Great article Alan
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Myself and another group member went up in the yak52 the other day for the yearly advanced spinning cx. After all the sop stuff both ways up we tried the AC method. In a right hand erect spin, applied opposite aileron, stick slighly forward and full power.. then as described. The recovery was almost shocking in that it was so quick and abrupt. After a number of attempts we both landed as converts..
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You can´t give a general statement to spin recovery and power, it depends on so many effects that it is different for different types of airplane.
One effect is the gyroscopic pitching moment. If you are yawing, (and you wildly do it during a spin) the engine acting as a gyro is producing a pitching moment. Engine rotational direction is constant, so pitching moment direction depends on yawing direction. This means for a right turning engine and a right spin a nose up pitching moment. Having more engine rpm (which must not be confused with more power for variable pitch props) makes you spinning more flat, less engine rpm makes your spin steeper and therefor (generally speeking) more easy to recover. For a left spin it is the other way round. Having two engines with different rotating direction, the gyroscopic effect is compensated. This is also partially true for geared engines where the rotation direction of crankshaft and propeller are reversed (i.e. Rotax 912/914). The heavier and faster rotating crankshaft nearly compensates the lighter and slower turning prop with its much higher inertial radius.
The other effect is the propeller slipstream giving you more rudder and elevator authority, which generally helps you in recovering a spin, as long as the slipstram really reaches the empenage due to the high angle of attack (it might run just above the tail in a flat spin and for long fuselages), otherwise it can´t help.
So it depends on the special type of plane what happens, its the job uf the flight test team to determine all the effects during certification tests, the POH should hold all the informations needed for best recovery.
There is a very impresive educational film from the german luftwaffe, recorded in the late 30s, which shows all this effects in flight for different types op plane. At least 3 planes were lost during the film flight tests, so the film shows really interresting tests details, they really tried any possible trick during steep and flat spins.
I don´t know if it exists somewhere in the web or can be purchased somewhere.
One effect is the gyroscopic pitching moment. If you are yawing, (and you wildly do it during a spin) the engine acting as a gyro is producing a pitching moment. Engine rotational direction is constant, so pitching moment direction depends on yawing direction. This means for a right turning engine and a right spin a nose up pitching moment. Having more engine rpm (which must not be confused with more power for variable pitch props) makes you spinning more flat, less engine rpm makes your spin steeper and therefor (generally speeking) more easy to recover. For a left spin it is the other way round. Having two engines with different rotating direction, the gyroscopic effect is compensated. This is also partially true for geared engines where the rotation direction of crankshaft and propeller are reversed (i.e. Rotax 912/914). The heavier and faster rotating crankshaft nearly compensates the lighter and slower turning prop with its much higher inertial radius.
The other effect is the propeller slipstream giving you more rudder and elevator authority, which generally helps you in recovering a spin, as long as the slipstram really reaches the empenage due to the high angle of attack (it might run just above the tail in a flat spin and for long fuselages), otherwise it can´t help.
So it depends on the special type of plane what happens, its the job uf the flight test team to determine all the effects during certification tests, the POH should hold all the informations needed for best recovery.
There is a very impresive educational film from the german luftwaffe, recorded in the late 30s, which shows all this effects in flight for different types op plane. At least 3 planes were lost during the film flight tests, so the film shows really interresting tests details, they really tried any possible trick during steep and flat spins.
I don´t know if it exists somewhere in the web or can be purchased somewhere.
