NO INTENTIONAL SPINS Jabiru

[DarkSarcasm]

If I was a lawyer Darky, and acting for a victim, I'd search the web looking for the past history of the pilot and his/her attitude. This will often bring to light several "priors" which helps to shorten the arguments considerably, particularly when there is a jury involved

Do you mean where the manufacturer is the victim or the pilot? If I was acting for the manufacturer I'd do that so then if there were any I could say 'see he was already a silly sod, no matter what we tried it've likely all gone pear-shaped for him anyway'. Alternatively if I was acting for the pilot that would only help if the person didn't have any - although I'd still check so I could attempt to find a way to rebut it.

 

I fear that we are getting too deep into discussion about our hypothetical court case and I think that might be my fault (it's just force of habit I guess)

 

ADDITION: just read Qwerty's post below and realised that Turbo was referring to posts on forums like this for evidence of 'priors', oopsie. Now I've noticed that though, I completely agree with what he said. I guess I was too into my 'lawyer analysis' mindset

 

 

[Guest Qwerty]

Good point Turbo, If any of us on here are involved in any sort of incident there is plenty of evidence here that all of us are very careful to understand exactly what we are doing and that we stick to the letter of the law in all our endevours.

 

It can be seen from the robustness of the debate on this thread that we persevere in our persuit of understanding.

 

 

[farri]

Austflight Aviation,Maxair Drifter,owners manual.

 

"In view of both seats,"Intentional Spins Prohibited". :stirring pot:

 

Frank.

 

 

[Guest drizzt1978]

Oh dear I can believe We have hit eight pages on this......

 

Perhaps im working too much.....

 

 

[Tomo]

It can be seen from the robustness of the debate on this thread that we persevere in our persuit of understanding.

And that is what I so love about this place... it is always a good time to get everyone thinking again, albeit quite a simple question.

 

And yes, I've been thinking about it, and I can see very well where Qwerty is coming from. The "No Intentional Spins" quote has a indecisiveness about it, implying ''it can be spun, but it isn't recommended'', right!?

 

And coming to think about it, that is probably the best way to put it really... because, it gives you the choice wether you are going to obey the placard/manufactures/RAA's laws, resulting in a more confident and better pilot in my opinion.

 

If it had "No Spins" it's implying that the aircraft can't be spun, if it is, it will immediately fall to bits! Just imagine you accidently (you should never ever get that, but!) go into a spin, and you look down see "No Spins" it will give you more panicking thinking this things gonna fly to bits! resulting in bad/rough flying trying to get out of it, causing more structural damage in the long run, or worse case, flying to bits!!

 

Whereas, If you get into the above situation for some unknown reason and seeing "No Intentional Spins" will give you the small amount of comfort that it obviously can handle a spin, so you will be less radical and think it through properly (unless of course the ground is near by! then no amount of stickerage is gonna help!).

 

You then obviously better get it thoroughly look over by appropriate persons.

 

The way I see it, "No Intentional Spins" means the aircraft can be spun, definitely not recommended, but it won't fly to bits the minute your there, it has been tested etc...

 

"No Spins" means just that! Obviously there is a reason why, and it would be suicidal going there.

 

Just my little analogy to the question!

 

Now... "No Intentional Speeding" - see it can be done, and most possibly safely, but your leaving the safety and entering the risk that is definitely involved. Not only for you, but for others as well...

 

 

[turboplanner]

Tomo, unfortunately you have been influenced by some very irresponsible posting, and I would hate to think you became one of its victims.

 

Suggest you read the posts over again taking note of the responsible ones, and you will find that while there are some aircraft that might fly to bits, the biggest danger is the pilot ripping the wings off a perfectly good aircraft as he/she is taken by surprise and reacts instantly by the natural instinct to pull the tick back.

 

This thread contains some of the worst kind of playing with semantics when the intent should be to make our sport safer.

 

 

[Guest Qwerty]

I agree with Turbo. And we have yet to get to the nub of the question. Why on earth include the conditional "intentional" in the placard when a simple "No spins" seems at least on the face of it to be more succinct.

 

BTW Tommo, aircraft generally dont suffer any undue stress during a spin or a spin recovery and certainly should not fly to bits. A spin is really quite a gentle affair. But it is something that must be taught by an instructor in the right environment, a spin can be disorienting the first time.

 

 

[Tomo]

Turboplanner: I'm sorry If you've misunderstood what I was trying to say... I'll try again:

 

A friend rings me up and says, "can you take me for an aeroplane ride?" and I say yes lets go... right! So out we go for a fly, now whilst we are up there he asks, "I've seen a video on youtube of this fella pointing at the ground and... it's spinning... can we do that? And so I've got to explain why we can't... Now that would be preventing an "Intentional spin" would it not? The placard would be relevant right?

 

Same scenario but he hasn't asked for anything but for some unknown reason, slow flying maybe and an combination of thermal sink steep turn etc... we suddenly find ourselves pointing at the ground in a spin, that would be an "Unintentional spin" ??

 

Please don't think I'm for spinning in uncertified contraptions!

 

Qwerty: Yes I understand what you mean, I've actually experienced 3 spins... In a Drifter with Wayne Fisher.

 

In a Glider they teach spinning till the cows come home, getting you to unspin on a certain heading etc...

 

 

[farri]

And that is what I so love about this place... it is always a good time to get everyone thinking again, albeit quite a simple question.The way I see it, "No Intentional Spins" means the aircraft can be spun, definitely not recommended, but it won't fly to bits the minute your there, it has been tested etc...

 

"...

Tomo,tell me how you know the aircraft can be spun and won`t fly to bits.

 

Like a few others, you`ve made an assumption and assumptions can be dangerous.

 

Frank.

 

 

[Tomo]

Tomo,tell me how you know the aircraft can be spun and won`t fly to bits.

Good question... And yes by that I am assuming that the aircraft manufacturer has tested it, and that brings us back to Qwerty's original question about the clarity of the placard. The first time you read "No Intentional Spins" we think it is capable of it, but it's not recommended...?

 

We know that isn't the case, but at first, that is what it kinda sounds like it implies, hey?

 

By the way, I'm just thinking this through... so feel free to instruct me otherwise if you think I'm endangering myself, I want to be the safest pilot I can be.

 

 

[Guest Maj Millard]

OK, 'Intentional spins prohibited' is fairly simple for me to fathom. Our regulator doesn't want us to intentionally put the aircraft into a spin. Just like in a GA aircraft, they don't want you to intentionally switch off the engine either. They may consider that 'dangerous and reckless operation' which is why so many 'well trained ?' pilots end up on somebodys roof the first time the prop stops for some reason, instead of reaching a more suitable landing site. IMOP

 

However, we are allowed, and possibly encouraged to practise stalls during our flight training aren't we ???. Folks if you are going to practise stalls anytime..'YOU BETTER KNOW HOW TO GET OUT OF A SPIN...INCIPIENT OR OTHERWISE'. Besides the techniques are basically the same for either.

 

During solo stall practise in a Cessna 172, I have dropped a wing and entered an incipent spin. (with flaps) The only difference between an 'Incipient spin' and a 'real spin' is that the incipent spin had been allowed to continue into a real spin.

 

The Jab wing is not far from that of a Cessna, regardless of what Stiffie and his boys, and girls, will try to tell you. If a Cessna will spin, so will a Jab !. The only difference being...I know the Cessna has everything big enough to get me unspun......I can only hope the Jab does also.

 

Spin testing and exploration is normally conducted with an anti-spin chute mounted to the tail, just in case those things aren't big enough !!...And Oh, when I did unintentionally enter into an incipent spin in the 172, as suggested by my instructor I was at least 4000', I'm sure I had the thing back flying in a couple hundred feet !. Being a good instructor he had already showed me spin recovery technique, prior to letting me loose solo, to practise stalls..........................................................................

 

:kboom:

 

 

[farri]

Good question... And yes by that I am assuming that the aircraft manufacturer has tested it.By the way, I'm just thinking this through... so feel free to instruct me otherwise if you think I'm endangering myself, I want to be the safest pilot I can be.

Tomo,please don`t think I`m having a go at you because I`m not and I don`t think you`re endangering yourself,either.

 

We`re analysing the wording of the placard not the aircraft it is fixed to,it could be fixed to any aircraft and " No Intentional Spins" in no way says anything about the aircraft that would indicate it`s airworthiness and wheather it would fly to pieces or not and I feel we need to stress this for those who may not be aware of it.

 

Cheers,

 

Frank.

 

 

[Guest Qwerty]

What placard is in the chipmunk. There is a significant difference between a drifter and a Jab which are stable in spin and the Chipmunk which we are informed will/may develop a spin through to a flat spin. Now a flat spin I am afraid of.

 

 

[turboplanner]

What placard is in the chipmunk. There is a significant difference between a drifter and a Jab which are stable in spin and the Chipmunk which we are informed will/may develop a spin through to a flat spin. Now a flat spin I am afraid of.

It said "SPIN AND YOU'RE ******"

 

Unfortunately I didn't noticed it when getting in.

 

I wouldn't wish the unexpected experience on anyone

 

 

[farri]

At the risk of keeping this thread going.

 

Quite a few years ago an instructor from Townsville was doing some flight tests on a "Goldwing",( it`s a canard configuration and a basic Ultralight),he was adding and removing ballast, trying to the get centre of gravity correct.

 

On the final flight he didn`t get it right and at 2400 feet the aircraft stalled,( Keep in mind that a canard,if set correctly,is supposed to drop the nose before the wing stalls), anyway ,the AC went into a Flat Spin and he simply had to sit there and ride it to the ground.

 

He was extremely lucky that his number wasn`t up and he only ended up with some injuries to himself and the AC.

 

I don`t know what became of him after that, someone might remember this one.

 

Cheers,

 

Frank.

 

 

[djpacro]

David, you've added quite a few more discussion points there. I won't respond to them all now - off to Lilydale soon for a day of aerobatics and spinning.

 

The type certification requirement for normal category, VLA etc is only to demonstrate recovery from, in effect, an incipient spin - there is no statement regarding recovery from a fully developed spin, especially one aggravated by controls and power.

 

The Grumman Trainer is a well-known example of a type where an unrecoverable spin will develop after a few turns. Nev also mentioned the example of the Airvan earlier.

 

Cessna 172 - if it is approved for spins in the USA then it is approved for spins in Australia - our Type Certificate Data Sheet is a direct copy of the USA one and the original manufacturer's flight manual applies.

 

Cessna 150/152. It can spin flat. Letting go of the controls, or even using the Beggs-Mueller technique (power off, release the stick and full rudder opposite the yaw) will not always result in recovery.

 

Too many friends have died in spins, I am very wary of them although I do some most times I go flying.

 

 

[turboplanner]

Most AC have to be deliberately held in the spin and many will not stay in the the spin more than a couple of revolutions e.g. the Cessna 150.

The AC is simply stalled during spins it is under very little stress and therefore it will not fly to bits...lets clear that up right now or we will have paranoid RAA pilots scared XXXXless about spinning and we don't want that.

 

Let us clear this up, it is the spin recovery that can overstress the AC not the spin itself.

 

Spin training should be mandatory but it isn't.

David, you are on the money, but I have a couple of reservations.

 

I'm guilty of an earlier generalisation.

 

To get a clear understanding we should separate the incipient spin from the spin, and separate the spin from the pilot's reactive input.

 

In the incipient spin, where correct control action is applied quickly, I'd agree there is very little G force, but my feeling is it's more than the 2G felt at 60 degrees of bank. So no reason for an aircraft to suffer strain or break up.

 

The operative word is "correct control action" and when that is taught by a qualified instructor and the pilot has recency, he/she has a good chance of a safe recovery virtually anywhere down to Final in the circuit.

 

For that reason I'm a strong promoter of training in Incipient Spins, which I've received in both GA and Rec Aviation.

 

Incipient spins only involve a part rotation, but that's plenty to teach you the correct control inputs.

 

I Your suggestion that spin training should be mandatory poses a problem for RA pilots, which came to light in a similoar thread on aerobatics. We don't have suitable aircraft in the schools and it would involve the extra expense of being trained by an aerobatics endorsed trainer in an aerobatic aircraft.

 

Given the reaction of one of our members who did an aerobatics course, it's something to be recommended, and which would make you a more experienced pilot, but I'd suggest the incipient spin training we get shows us how to recognise a developing spin and take corrective action.

 

In the spin itself, I'd agree that theoretically since one wing is stalled and the other is free to rise there's no stress there either - in the early stages and before the pilot comes into the equation.

 

To you, with your experience, I imagine an unexpected spin coming on would be a routine experience which you would react to subconsciously with correct control inputs.

 

However, on this forum we have a lot of people who have never experienced one, and have not been trained on recovery from incipient spins.

 

They may freeze, and let the aircraft exceed VNE, or they may try to get the ground out of their face too soon, and both those actions can break the aircraft up.

 

I realise that's what you are saying, and I'm not disagreeing with you, just emphasising that we have to allow for the early solo student, who will not know what to do if he/she gets a little tight turning final etc. so it should not be passed off lightly.

 

Your comment that a C150 will noty stay in a spin for more than a couple of revolutions is not correct as one young man could attest to if he was here, but he died after spinning vertically down from 1000 feet, neatly drilling the ground spinner first, with all debris confined to a radius of about 4 metres.

 

This aircraft didn't break up in flight, but went in with full up elevator, almost certainly because he had never been trained in spin recovery.

 

If that can happen in an aircraft with millions of dollars spent on it's design, then I'd argue that whatever the placard said, no pilot should be entertaining the thought that "well it doesn't stop me trying out an unintentional spin"

 

I also have an issue with the theme from some pilots (I notice they are usually the same people) who maintain that they can conduct aerobatics, spins etc with no unsafe stress to the aircraft.

 

No one that I know of has a G Meter in their posterior wired to their brain, and if highly trained and skilled aerobatic pilots fit a G Meter to their aircraft to record high loadings, I'd suggest its very unrealiable for a recreational pilot to think he can judge G forces accurately once his adrenaline is running and the aircraft starts rotating.

 

As an example, there were many times when I would go out in a race car for four or five runs in a night, and if you asked me at the end of the night how it went I'd have said the track was smooth and no one hit me.

 

However the next day in the shower I'd be black and blue down one side from being thrown against the side of the car by the G forces.

 

So just because you've done something and the aircraft still appears to be unstressed, you can't be sure without a metallurgical examination.

 

For those who say this thread is separate from aircraft operations and is just about grammar on a placard:

 

The concise Oxford Dictionary lists the meaning of the "intentional" as "done on purpose"

 

So if you decide to try an "Unintentional Spin" you'd be doing it on purpose, and you'd be amazed at how many passengers tell people about the "loops and aerobatics they experience" and how many instant cameras there are on the ground these days.

 

If you would be more comfortable with a sign saying "No Spins" or any other wording, there's nothing to stop you putting an argument to the Regulator.

 

 

[Guest Qwerty]

David Isaac

 

I agree 100% with your comments on the spin, your comment is acurate, balanced and informed. The purpose of the thread however was to get to the bottom of the ambuguous placard. I do not understand why the placard isn't simply "No Spins".

 

 

[farri]

I do not understand why the placard isn't simply "No Spins".

As I see it ,this thread was intended to question the wording of the placard and analysing the spin itself is a seperate issue.

 

As I pointed out earlier,RAA registered aircraft are not permitted to do spins and every RAA pilot should know this, therefore, it is questionable wheather the placard should even be fixed to RAA aircraft,I do agree though, "No Spins", is more appropriate.

 

Frank.

 

 

[Guest Qwerty]

Since it seems that we are discussing spins, I have a question...... What the hell does CASA expect of a non spin trained pilot who finds them selves in a spin.

 

I can't even imagine what it might be like flying an aeroplane with a great big empty void in knowledge of that area of performance. Of the spin.....I know where it is, how it feels, and how to deal with it, and importantly I know how, why and what I am staying away from, particularly in the circuit.

 

How do pilots deal wiht a lack of knowledge like that???

 

 

[turboplanner]

Since it seems that we are discussing spins, I have a question...... What the hell does CASA expect of a non spin trained pilot who finds them selves in a spin.

They enter him into the annual statistics Qwerty.

 

There shouldn't be too many of those if they've been trained in responding to Incipient spins though, or am I the only one who's received training.

 

 

[djpacro]

Only the "M" model on is legally spinnable.

The Type Certificate Data Sheet for the Cessna 150 lists the following models as being approved for spins: 150, 150A, 150B, 150C, 150 D etc through to the 150M plus the Aerobat variants. It also notes: "Intentional spins with flaps extended prohibited"

 

Djpacro how you would flat spin a C150 is beyond me unless Fat Albert and his mate were stowed away in the luggage compartment (joke). The C150 spins almost vertical, goes through about 2.5 rotations and the airspeed starts to increase (at that point no longer stalled) and you end up rotating in a spiral dive with a face full of ground and a rapidly increasing airspeed.

David, flat spins in a Cessna 150 Aerobat (model M from memory) by personal experience entered from a skidding turn with some power and aileron, also that of two friends, flight instructors (one has his own Aerobat and has done quite an extensive assessment). See this video of a 152 - the spin aggravated by inspin aileron - 60 turns:

Sewanee Aerobatic School - Spin Training

 

I've never had any trouble holding a 150 Aerobat in a multi-turn spin even with power off and neutral aileron. Some examples may have a tendency to spiral, a more positive entry generally fixes it. 152 has a greater tendency to spiral but a suitable entry technique will give a stable spin. Refer also Bill Kershner's book, the Basic Aerobatic Manual - lots of info on spinning the 150 and 152.

 

Djpacro,I hope you had a great day of aeros on Sunday, the Decathlon is a nice AC (don't forget to check the spars). A few years ago I did a 360 degree inverted steep turn in a Decath at Warnervale...had a headache for hours!!! A week later inspection revealed cracks which resulted in the replacement of both wing spars...whoops.

Thanks, was a good day. Another good subject for discussion but, to get back on topic ......I just came across this note in FAA Advisory Circular 61-67C, Stall and Spin Awareness Training: "The pilot of an airplane placarded against intentional spins should assume that the airplane may become uncontrollable in a spin." Next time this subject comes up I will simply refer to that.

 

 

[GraemeK]

Just watched the 60 turn spin - Catherine can teach me spins any time, remarkable!

 

 

[djpacro]

David, here's an extract from an article that Mal Beard wrote in a local newsletter some years ago.

 

"While Eric Muller recommends the use of in-spin aileron as part of a normal spin recovery,. in some a/c it may have an adverse affect. The use of inspin aileron in a Cessna 150/152 Aerobat has the opposite affect to what you would expect. Inspin aileron causes the spin to go flat.

 

This is the result of the very effective Frieze Ailerons that are fitted to the Cessna wing creating a lot more drag on the aileron that is deflected up.[inside aileron with inspin aileron applied]

 

In the Cessna 150/152 outspin aileron will cause the spin to stop. The reverse airflow through the propeller will cause the motor to stop rotating, just to add a bit of extra excitement and to further raise your heart rate.

 

In the unlikely event that you find yourself spinning inverted in the Cessna it is likely that the use of out-spin aileron will have the normal affect of flattening the spin while in-spin aileron will help during the recovery. This is due to the frieze aileron being in-effective when spinning inverted, as the hinge point of the ailerons is on the top surface of the Cessna wing, a smooth surface is maintained when the wing is inverted regardless of aileron deflection, and A of A should come back into play. Due to a lack of an inverted oil system in the Cessna 150A/152A I have being unable to flight test the above theory inverted, although the use of in-spin aileron to flatten the upright spin has being tested over a number of years and a countless number of spins.

 

A word of warning to anyone contemplating flat spinning the Cessna 150A/152A. A positive hands on spin recovery will be required. Allow several rotations for the recovery to be effective. Also allow for an air restart as the motor will probably have stopped rotating. About 6000 feet plus minimum starting altitude."

 

Extract from an article by Gene Beggs in Sport Aerobatics of October 1985:

 

"In my telephone conversation with Bill Kershner, he told me of a spin mode in his Cessna Aerobat from which he was unable to recover using my power-off, hands-off, opposite-rudder method of emergency spin recovery.... …

 

…...a plain old 1975 Cessna 150 Commuter …

 

If I placed the aircraft in a spin to the left with the power on as might happen with a student who did not correct for the “P” factor properly, and let it spin with the power on for two turns or more, and then cut the power off, released the yoke completely, and then applied full right rudder and held it, the aircraft would continue to spin and showed no sign of recovery evern after as many as 10 turns! I would then place the heel of my hand on the padded center portion of the yoke and briskly push it forward, and the aircraft would always recover promptly in one additional turn ....

 

I found that the Cessna 150 would spin very docile, as long as the ailerons were held neutral and the power completely off in either direction .. Trouble developed only in the spin to the left, either when the power was left on or when “in-spin” aileron was applied and the aircraft permitted to turn two turns or more ..."

 

I haven't let it do as many turns as either Mal or Gene and certainly nowhere near as many as Catherine in that video! 192 ft per rotation ... hmm, a little bit more arithmetic and we could calculate the angle of attack.

 

Cessna produced a booklet in 1978 about spinning and much of that information is provided in this article in Flight Magazine - note that there is no difference in spin characteristics identified between the straight 150s and the Aerobats. Most of this info is also provided in Kershner's book.

 

 

[turboplanner]

Thanks DJP, that should bring us back to reality.