Topic: Spin entry/recovery

There are two reasons for this thread:

1. I recently maidened a Air Loisers/Sola Models/VQ Zero. There was possibly about 5-10mph wind, and I flew a few circuits, a couple rolls and a couple of reversals. Only my last reversal into wind, saw the model fall at the top and spin in. Right into the ground..one written off Zero. I must have lost so much speed into wind at the top of the reversal, that when I rolled the model onto its back and pulled to execute the turn the model must have stalled a wing and started the spin.
I was at some hieght, but I tried rudder and all other inputs to no avail, and the time goes so quickly you run out of thinking/reacting time.

Thinking back, should I have added power to get airflow over the surfaces and then put in some down elevator even though the model seemed to be spiraling straight down anyway?

2. I want to go for my B cert, and spins seem to avoid me. I tried with my CAP 232 last year after shifting the cog back because it failed to spin, then it span and it span so fast that centering controls didn't stop the spin.
Whats the recommended recovery from a real spin? Throttle up, down elevator and opposite rudder?

3. I have some trouble still entering a spin, I slow it right down into wind and hold up elevator and then apply rudder, but unless I do it quick which flicks it in, it seems unwilling to fall into a spin.

So please can I have the definative spin guide gents.

Ta
Wes

Whats the best recovery?

Firstly in your B if you add movement to flick the model into a spin you've failed, slow the model down staright and level at height and it will stall itself, dropping a wingtip, you then add the rudder in the same direction as the tip that dropped, then full up elevator full aileron and full rudder, with throttle on idle, when its time to exit if the model wont stop like you say, centralise the sticks and add the opposite aileron....this works for me on some of my models, if not try increasing throws, different speeds etc...

good luck
Jamie

Each model will often require a slightly different technique, but adding power, and down elevator normally works for me......................simply reversing the controls (rudder & aileron) won't necessarily work as the reason your in the spin in the 1st place is loss of forward airspeed...................so to get it back again, you'll need power, and the nose down.

Phil

Standard recovery is throttle to idle, ailerons central, full opposite rudder and steadily (over a couple of seconds) push to full down (or up if it's spinning inverted). 

Incidentally Eric Muller (ex fullsize European Aerobatic champion) says stick-back and in-spin aileron.  Can help if the elevator blankets the rudder in a spin.

Note that as an aeroplane starts to come out and the nose drops the rate of rotation may increase for a bit (conservation of angular momentum).

Aileron can be critical - mis-use of aileron can prevent some full-size a/c from recovering.

Just read an interesting description of Chuck Yeager accidentally spinning a somewhat modified F104 starfighter - 14 turns of flat spin from about 100,000 feet to ground level. 

Bruce

Firstly in your B if you add movement to flick the model into a spin you've failed, slow the model down staright and level at height and it will stall itself, dropping a wingtip, you then add the rudder in the same direction as the tip that dropped,

Is that true?  I hope not, but if so it will further reduce my opinion of the BMFA.

Hi Mpx,

How would that reflect so badly on the BMFA? Surely the point of the manouvre is to show you  that you cantip-stall on demand and recover with no loss of composure? Most planes I would like to see at displays; aerobatic or scale; have a definite tip stall tendency, so it seems wholely appropriate to test how well a pilot copes with them, in a planned and methodical manner.

I subscribe to the down elevator and centred rudder/elevator approach to exiting a spin. But I guess its whatever works best on your model.

Cheerio,
Rob.

I believe the BMFA BTest requires  you to bring the model to just before a stall and then apply rudder to start the spin, ailerons can not be used until the nose drops. Opposite rudder and down elevator, ailerons centred and power applied is the normal method of stopping a spin.. However a lot of models will recover if you apply power and centre everything.




   Tom

... Surely the point of the manouvre is to show you  that you cantip-stall on demand and recover with no loss of composure? ...

Very few of my airframes will tip-stall without rudder input.  I personally view a non-straight stall as a defect in an airframe.

As tomkfly says you can use rudder just before it stalls.  IIRC the requirement in the rules is that the other wing does not rise : ie the plane drops into a spin as opposed to entering a flick roll.

Stuart

Is that true?  I hope not, but if so it will further reduce my opinion of the BMFA.

*sigh*

No, of course it isn't true - just another myth. The actual words (wot I 'as just copied from the book on the BMFA website, an exercise that took less than two of your earth minutes) are:

"The model must be flown into wind and before it reaches a point in front of the pilot the
throttle must be closed. As the model slows down, level flight must be maintained by steadily
increasing amounts of up elevator until, at a point approximately in front of the pilot, full up
elevator is reached (the model should be slow and nose up at this point but not
climbing).

Full rudder must then be applied and the model allowed to fall into the spin. The model
should not stall and then spin but it should be flying close enough to the stall so that applying
full rudder will cause one of the wings to stall and initiate the spin
Ailerons may be used in the spin (and many models will not stay in a spin without aileron
being used) but they must NOT be applied until the model has begun to fall. Note that this
does not mean that the model must actually be spinning before the ailerons are applied but
it must at least be falling into the spin."

Generally a well thought out set of words and conditions. In fact the only bit that I might take (very) minor issue with is the requirement for the throttle to be closed, because there are some models that are reluctant to enter (or in some cases exit) a spin predictably without a little propwash over the tail feathers and there are some where the idle may not be that reliable through the spin. But these are issues which could be discussed and agreed with the examiners on the day - possibly by agreeing a "fast flight idle" setting to be used for all but the landing approaches.

When I did my B-cert (back in the dim and distant past - in the first year of the scheme in fact) the model I had was very reluctant to enter an upright spin, but would spin beautifully inverted. I discussed this with the examiners, even allowing one of them to verify this for himself. So we agreed that I would do two extra inverted circuits with a three-turn inverted spin between them - ie inverted flight followed by an inverted spin, recovering to inverted flight and another inverted circuit. This was deemed an acceptable variation to suit the model, and certainly a better option than simply doing an upright spiral dive (as allowed in the rulebook).

PDR

Thank goodness for that, the BMFA is sensible after all!

The reasons, wotrob, for my objection to the description of waiting to apply rudder in the direction of incipient spin are:
1.  Many models will stall straight ahead.
2.  Waiting to see which way it spins and then adding pro-spin rudder if it does tip stall, is pointless. It teaches and demonstrates nothing about preventing the accidental spin, in fact quite the opposite, it reinforces the accidental spin.  And it teaches nothing about a controlled spin.  So either way, it is worthless as a technique for preventing, or for deliberately initiating and controlling a spin.

Very few models really spin, and very few need positive recovery action such as opposite rudder since the overwhelming majority stop "spinning" if you release the controls.  The most important thing to do is unload the wing by letting the elevator return to neutral, remove all yawing and rolling force by letting rudder and aileron return to neutral.  It is very rare for models to get into a true spin that needs opposite rudder to stop it.

It is very rare for models to get into a true spin that needs opposite rudder to stop it.

Rare, but not completey unheard of. My Phil Ramsay Pitts S2 was one such. If you got it spinning and then applied a little out-spin aileron to flatten it out and reduce the rotation rate it would settle in after a couple of turns. From that point forward you could centre the controls (with any power setting) and it would simply continue in the spin at a low rotation speed and fairly high rate of descent. I once let it continue from 750feet(ish) to below eye level the valley next to the field before chickening out. Opposite rudder, followed by forward stick and some power recovered it in about a turn and a half - and a hundred feet. It was one of those days when I learned how to make panic look cool and controlled...



PDR

And I have had a couple of models that got into genuine spins and didn't want to come out in a hurry even with full opposite rudder, but it is rare.  I still have my Phil Ramsey mini-Pitts S2 first flown in summer 1982, I intend to convert it to leccy.  I never tried out-aileron in a spin with the mini-Pitts though I use it regularly with things like Synergy and CAP 10 and 232, might give it a go when it flies again.

And I have had a couple of models that got into genuine spins and didn't want to come out in a hurry even with full opposite rudder, but it is rare.  I still have my Phil Ramsey mini-Pitts S2 first flown in summer 1982, I intend to convert it to leccy.  I never tried out-aileron in a spin with the mini-Pitts though I use it regularly with things like Synergy and CAP 10 and 232, might give it a go when it flies again.

The mini Pitts was an S1 - the S2 was the 1/4 scale one intended for a .91, so I put a tweaked ST2500 in mine. It was a heavy old bus but very rewarding to fly.

I've also got a half-built Ramsey Mini Pitts somewhere in the loft - started in 1985ish for a super tigere X45, but never finished.

PDR

I had plaenty of height with my Zero, but neutral controls still spinned, though like an axial aileron dive rather than a tail spin, opposite rudder, opposite aileron...nothing worked....it just kept going until the inevitable demise. 

My mini Pitts is definitely an S2.  The S1 is single cockpit, the cockpit being right up against the top wing cabane struts.  The S2 is two cockpit, the front cockpit being up against the cabane struts and the rear cockpit some distance back.  They were not all fitted with a long canopy to cover both cockpits.  The front cockpit is often unused and covered over, with no windscreen.  My mini Pitts fuz has a circular indentation with fastener indentations around it where the front cockpit should be, and the second cockpit with canopy a long way back from the cabanes.  It's unmistakably an S2.  If you look at Phil's photos on www.philramseymodels.freeserve.co.uk/mini%20pitts%20page.htm you can see the distinct gap betwen the canopy and the cabanes, then google images for Pitts S1 and Pitts S2 and you will see the confirmation straight away.

Thank goodness for that, the BMFA is sensible after all!

The reasons, wotrob, for my objection to the description of waiting to apply rudder in the direction of incipient spin are:
1.  Many models will stall straight ahead.
2.  Waiting to see which way it spins and then adding pro-spin rudder if it does tip stall, is pointless. It teaches and demonstrates nothing about preventing the accidental spin, in fact quite the opposite, it reinforces the accidental spin.  And it teaches nothing about a controlled spin.  So either way, it is worthless as a technique for preventing, or for deliberately initiating and controlling a spin.

Very few models really spin, and very few need positive recovery action such as opposite rudder since the overwhelming majority stop "spinning" if you release the controls.  The most important thing to do is unload the wing by letting the elevator return to neutral, remove all yawing and rolling force by letting rudder and aileron return to neutral.  It is very rare for models to get into a true spin that needs opposite rudder to stop it.

MMMmmmm....You obviously have never seen an Aero tech model fly / crash then!! (I maybe tooo old, you maybe tooo young)!, but these models used to go into an unrecoverable spin for a pastime (check "search" I think there is a thread on these somewhere).
A lot of models will spin very easily...but when the sticks are centred...they will start to spin in the opposite direction...then you buy the farm.
IMHO spinning models to low/ aft c/g / low fuel level has probably totalled more models than any other manoeuvre!!.
Remedy: Start at dot height...and give yourself loads of thinking time. Good luck. Simon.

And earlier VMAR were notorious for flicking into and unrecoverable spin with no provocation from the pilot.  I once saw a Hot Pot "trainer" in the late 70s spin all the way to the ground with a very capable pilot unable to stop it, and Zippo's Arc Ready 2 "trainer" has proved itself to be very dangerous with a spin that can be very hard to get out of.  But it is still true that it is very rare for models to spin properly for those models that do are but a tiny number of the total models.  The overwhelming majority of models will stop "spinning" when the controls are released, indicating that they are doing more of a tight control line turn than a true spin.  If you stall a model in a turn and it drops the wing the overwhelming majority will stop and recover as soon as you unload the wing.  Most models need a bit of aileron to get a spin started from level flight, I have aerobatic models that won't go into a "spin" just with rudder, they fly around a tight control line descending turn.  This indicates very strongly that the inner wing is not stalling and in fact the model is being rolled into the spiralling dive.

The Zero had quite tapered wings, and being a radial cowl that helps eat up airspeed, so the ingrediants were there for a tip stall.

Just so suprised that an unrisky manouvre would have ended like this, but I can see how it happened now, climbing into wind, backing off power and rolling onto its back before pulling up elevator must have been enough to slow it and tip stall.

But it looks like some spins, even axial ones are just irrecoverable...certainly don't wanna repeat performance to see if it'll happen again.

But it looks like some spins, even axial ones are just irrecoverable...

What's an "axial" spin

PDR

Like an axial roll...but pointing at the ground :-[

That's a vertical roll - often perfomed on the exit of a Stall Turnip, not to be confused with the horizontal or parabolic Ham Roll (the most popular manoeuver on the typical club field). The true spin is often entered inadvertantly on the exit of a classical Cuban Seven.

HTH,

PDR

Have the Cuban Seven been released yet?

No, they're only available in a Beta test version. Personally I'll wait for the HD version to come out.

PDR

Stall Turnip,

    I love that, must remember it!

  I love that, must remember it!

I only wish it was one of mine, but to avoid accusations of plagiarism I must give the original attribution to "Pylonius" - the diary/satire column in Aeromodeller, circa 1974. The "parabolic" or "Ham" Roll is all my own work though, and I'm sure that on reflection you'll find that you enjoyed it more...

PDR

If anyone would like to experience a spin for real, and you can get to Gloucestershire Airport, you can share a flight with me in a Robin 2120A but I warn you that spinning is not for people who don’t like being thrown around in an aircraft.  But afterwards you will have a lot more sympathy for your model!  I believe that spinning is not part of the PPL syllabus these days, so even many full-size pilots have never experienced it.  After about 3 turns the Robin will often make a very sudden transition into a flatter spin characterised by a feeling of being thrown out sideways which is most disconcerting.  Recovery action often speeds up the rate of spinning for a turn or two rather than just stopping the spin, which adds to the fear/fun factor!

which adds to the fear/fun factor!

I think thats the pucker factor 

No spin in a ppl test?

I remember doing mine, the CFI putting the aircraft into a spin, and telling me to let him get it spinning before I started trying to recover!

I found it hard to just wait as everything you'd learnt was screaming "you don't want to be doing this".

Have to say recovery (in a Cessna 152 anyway) was trivial, it didn't seem to like the spin any more than I did.

Mind, the CFI was a nutter, prone to do things like loop - whilst in the circuit, downwind leg, at Biggin Hill on a weekend!!  I knew I was getting on ok when we went for a cross country, and he had a whiskey when we got to Stapleford Tawney ...

Memories

Nige

No spin in a ppl test?

I remember doing mine, the CFI putting the aircraft into a spin, and telling me to let him get it spinning before I started trying to recover!

I learned in a Robin 200, not even allowed to spin. Didn't stop the instructor forcing it into a wingdrop with some serious slow speed yaw, just to check i picked the right rudder pedal..

Hi Mpx,

I take your point about when, even if, it would be useful to handle a tip-stall. Slowing to near stall speed with full elevator, and then kick full rudder to drop a wing into a spin would be the only way to test it safely (at height). But most tip stall issues I've had/witnessed have been low to the ground during take off or landing issues. No height to allow a recovery there then. And a rather unforgiving reception too.

My fave plane to spin at the moment is my Minihype. Lots of spins, very little height lost, and an instant recovery. It makes it so easy. My old Reflection, used to take one and a half revolutions to recover, and it took me ages to get used to it.

I love the sound of the inverted spin, thats another one to add to my list of must try moves. Is it the same entry/exit routine, but obviously inverted. Will try it tonight on the pc sim.

Cheerio,

Rob.

Going slightly of track.....my favourite spin is the inverted climbing flat spin. The first time I managed this with my UCD .46, I froze on the sticks...as it is just such an awesome manouvre. Takes a bit of stick juggling, but very rewarding when you get it right. Recovery?. Just let go of the sticks and it flies out on its own...love it!!.

If anyone would like to experience a spin for real, and you can get to Gloucestershire Airport, you can share a flight with me in a Robin 2120A but I warn you that spinning is not for people who don’t like being thrown around in an aircraft.  But afterwards you will have a lot more sympathy for your model!  I believe that spinning is not part of the PPL syllabus these days, so even many full-size pilots have never experienced it.  After about 3 turns the Robin will often make a very sudden transition into a flatter spin characterised by a feeling of being thrown out sideways which is most disconcerting.  Recovery action often speeds up the rate of spinning for a turn or two rather than just stopping the spin, which adds to the fear/fun factor!

My only experience of a full size spin was in a Puschaz (sp?) training glider.  I knew nothing about flying other than my training flights in the glider and I'd been practising stalls when the instructor asked me what I thought might happen if I applied rudder in the stall ... and then proceeded to demonstrate  .  I found it quite exciting at the time, but perhaps not so much a few weeks later when a similar glider (could have been the same one) actually spun into the ground killing both the instructor and the air experience student.  The theory was that the pupil (or perhaps the instructor) had stalled the glider and then locked his knees (in a panic?) thus preventing the instructor from applying the necessary opposite rudder to recover from the subsequent spin.  Obviously this is all supposition but it's made me very wary of deliberately spinning models, though I'm getting more comfortable with it.

Incidentally I also experience a loop in a Puschaz right over the top of Win Hill in Derbyshire - exciting and terrifying in equal measure 

Geoff

But most tip stall issues I've had/witnessed have been low to the ground during take off or landing issues. No height to allow a recovery there then. And a rather unforgiving reception too.

Which was half the point I was making.  At that stage the spin avoidance technique is to unload the wing and maybe, only maybe, add opposite rudder.  Learning to hold on the up elevator and then add pro-spin rudder would guarantee a major problem.  I said only maybe add opposite rudder because if you are not prompt enough at unloading the wing, and most people's natural reaction when it goes wrong at low level is to haul back on the elevator, then you simply prompt the plane to flick into spin in the opposite direction.

I love the sound of the inverted spin, thats another one to add to my list of must try moves. Is it the same entry/exit routine, but obviously inverted.

Pretty much.  Try it with aileron, that makes it very good.  Push rudder and aileron the opposite direction though, so full down ele, left rudder and right aileron, or right rudder and left aileron - sticks pointing together or away from one another.  Once it is going go to full power and be prepared to ease off the aileron enough to get a very flat inverted spin.  If you have a reasonably rearward CG you can do knife edge spins by moving the aileron and ruddder the same way, eg both left with full down elevator.  However if you try a standard spin entry it often won't get established knife edge, a way that usually works is to start from a vertical climb at high power, let the speed fall off a bit but down't wait until the plane is slow, then add full down and full rudder and aileron in same direction, if you have enough airspeed that throws the tail out and gets its momentum going and the model then slows and turns around and drops into a knife edge spin.  Try varying the throttle once the ke spin is established, the throttle controls the rate of rotation, its usually most spectacular at full power and fast rotation.  It usually recovers very quickly on centralising the controls.  But beware the staggering rate of loss of height during a ke spin, and the loss of height during recovery as the model takes time to yaw from ke to a dive and pick up forward speed, so don't get mesmerised and let it come too low.  Always start from very high to give yourself time to enjoy a ke spin.

Thanks Mpx,

I'll have my homework in by Monday!!

Cheers,
Rob.

I must admit with our foam Kerfuffles, me and a mate have been experimenting with just that manouvre.

Fly in fast, point her up then full down and right aileron, for a couple of off centre endo's then add full left rudder...sometimes it will knife edge spin, other times it flicks over onto her back and slowly harriers down inverted, sometimes with rotation..other times not.  Centralising the sticks and then pulling full up snaps it out of the inverted harrier, but can take a few seconds to start the transition.

Looks very cool, but must leave room for the exit manouvre. Sometimes the model falls backwards and a wierd whirry noise of air going the wrong way through the prop can be heard.
This I can do, normal spins.....still learning!

MPX you are correct in that the ppl you do not have to do the stall into a spin

i made sure that i did it for nearly an hour great fun
but sadly i no longer can afford the lessons  :-[
Ron

blimey HOW high did you start it???

               goony

My only experience of a full size spin was in a Puschaz (sp?) training glider.  I knew nothing about flying other than my training flights in the glider and I'd been practising stalls when the instructor asked me what I thought might happen if I applied rudder in the stall ... and then proceeded to demonstrate  .  I found it quite exciting at the time, but perhaps not so much a few weeks later when a similar glider (could have been the same one) actually spun into the ground killing both the instructor and the air experience student.  The theory was that the pupil (or perhaps the instructor) had stalled the glider and then locked his knees (in a panic?) thus preventing the instructor from applying the necessary opposite rudder to recover from the subsequent spin.  Obviously this is all supposition but it's made me very wary of deliberately spinning models, though I'm getting more comfortable with it.

Incidentally I also experience a loop in a Puschaz right over the top of Win Hill in Derbyshire - exciting and terrifying in equal measure 

Geoff

The Puchacz is perhaps a bit odd in that being the Polish millitary intial trainer it's designed very much with spin performance in mind. One was tested by the Empire Test Pilots School guys and found to be fully capable but not dangerous. From my experience there's really no excuse not to realise you're about to stall it though.

Having just moved house I have only just got back on line to read the spinning thread.  As an ex RAF QFI and as a test pilot I have done more spins in full size aircraft than I could possibly count and rather less with models.

With very few exceptions (e.g Gnat/Jaguar due to very adverse B over A ratios) full size machines spin predictably.  Modern training machines will recover within less than two turns if the controls are released.  Older designs (Harvard/Chipmunk/Jet Provost) require positive recovery action and will kill you if you don't use it.  I, personally, thought they provided better training value! 

The action is hammered in by rote: 1. Check direction of turn by reference to the turn needle, ensure throttle at idle. 1.  Apply FULL opposite rudder and ensure ailerons are neutral.  3.  Move control column forward until spin stops.  4.  Immediately centralise controls, roll to nearerst horizon and ease out of the dive.  The greatest gotcha is that the spin speeds up as it is recovering which has led to many believing that their actions are not working and giving up.  There are many stories of people, having jumped out, watching their aircraft flying away because it has recovered itself when left to its own devices.

This is for an erect spin.  Of course for an inverted one you ease the column back and it is vital to apply rudder against the turn needle, not what your senses are telling you.  There are minor variations in recovering swept wing aircraft.

I have not yet had a model that won't recover practically instantaneously when the controls are released but I find many are reluctant to enter a spin conventionally.  Frequently,  I find it has to be started by a flick manoeuvre with some power. 

Frequently,  I find it has to be started by a flick manoeuvre with some power. 

Thats what I find too...but wondered if the cog was not far enough back to make it fall into a spin.

Or possibly the CofG just a little further aft.