Stalls

[shafs64]

When i first sarted flying in 99 i was told to never use Aileronto pick up the wing after the stall. now i was reading the Jim davis PPL book and he says its ok to use the Aileron to help recover from a stall?

 

shafs64

 

 

[turboplanner]

You're not expecting a four line answer to this are you?

 

The circumstances play a huge part in deciding what to do, and your skill plays a huge part in deciding whether that decision is correct.

 

Suggest you read several books, particularly Stick and Rudder by Wolfgang Langewiesche, but more importantly get some one on one practical demonstration from your instructor because there's no point in memorising the theory without being able to identify whether your action is working.

 

 

[motzartmerv]

Hmmm... big can of worms this one mate..

 

We certainly teach NOT to use aileron near the stall, rather use rudder or nothing at all and fix whats broken by reducing the angle of attack..

 

The down going aileron (on the wing your trying to pick up) increases the angle of attack on that wing, which could put the wing through the critical angle.

 

That being said, like turbo said, circumstances are different and indeed aircraft are different. The thing is a lot of training acft don't actually stall anyway, they just mush out and develope a high sink rate, but the nose just waffles about, and ailerons are still affective.( of course they can stall properly, but need a great deal of coaxing.) Once the seperation point ( in a real stall) has moved forward far enough ailerons become inaffective anyway..

 

The best answer would be, talk to your instructor about it, and suss it out in the acft you are flying..

 

cheers

 

 

[Guest drizzt1978]

Perhaps if the wing has dropped too far, the rudder is ineffective but I have no Idea. If you ever run into My ex instructor (PM Me if you want that detail!) you could ask him, The stall training I did with him is.......in depth to stay the least. That being said, I was told never to do it. But as stated different Aircraft and different conditions????

 

 

[facthunter]

Technique.

 

Broadly speaking, I would rather see a pilot keep the stick in the centre when the aircraft stalls. Picking up the dropped wing with aileron is the instinctive thing to do and I would resist the temptation, and train yourself out of the habit, as often it will (as Merv says), cause the downgoing wing to become more stalled than would otherwise be the case. If it causes aileron drag then the speed will reduce on that side and again you are worse off.. Because you CAN use the ailerons on SOME aircraft, it doesn't mean it is a good idea. They can still bite if one day you are a bit more tail heavy or hit a patch of "chop" at the same time.

 

Incidently, once the wing has dropped substantially, there is no point whatsoever trying to pick it up with rudder. The nose will drop due to the weather-cocking effect of the fin and rudder. (Remembering that at this point you are not going very fast and the top rudder that you are applying will not have much effect). AS the nose drops (sideways) the speed will rapidly increase and THEN the ailerons will work again and you can roll the wings level, and recover from the dive that you will have entered

 

IF you don't roll the wings level and just pull the stick back you will be in a SPIRAL dive, and that is something else again.

 

Most pilots exhibit a fair degree of apprehension in a near-stall situation, but with proper training and a full understanding what you and your plane can do you will have a greater chance of surviving an upset. Nev..

 

 

[Barefootpilot]

Just a quick note you shouldn't "pick up the wing" with rudder you should only stop the wing from falling even further (rolling and yawing) If you try to return the wings to level with only rudder you are increasing the chances of entering spin. I'm sure Motz will probably be able to explain this alot clearer than I can (its been a very long day!)

 

 

[Guest Cloudsuck]

Just a quick note you shouldn't "pick up the wing" with rudder you should only stop the wing from falling even further (rolling and yawing) If you try to return the wings to level with only rudder you are increasing the chances of entering spin. I'm sure Motz will probably be able to explain this alot clearer than I can (its been a very long day!)

Well said Adam, you are exactly right! How do we spin an aircraft? We stall the wings and then kick in rudder.

 

Threrefore, if we stall the aircraft, get a wing drop and then boot in rudder to pick-up the wing, well you run the risk of a spin. If you try to pick it up with aleron (which is now outspin aleron) you run the risk of a flat spin.

 

My prefered method is use rudder just prior to the stall to keep the ball in the centre, when it stalls, the wing drops, unload the stick, apply power and roll off bank with co-ordinated aleron and rudder.

 

I think that the whole 'pick-up the wing with rudder' thing is miss used and should read; Pre-stall mush - pick-up the wing with rudder (keep the ball in the centre on approach to the stall).

 

In somthing like a Jab which is a non-event in the stall and you would really have to miss handle it to make it spin, it's probably not as bad. In my Sierra with full flaps, the stall is quite sudden and the wing drop is large. It would be quite easy to enter a spin if you kicked in too much rudder while trying to 'Pick-up a wing'.

 

 

[turboplanner]

It is extremely dangerous to offer "freeze frame" explanations to an inexperienced pilot, there have been several deaths in the past six months due to simpler mistakes than dealing with a wing drop. It is absolutely essential, if you are learning, to refer to professional books AND THEN DiSCUSS THEM WITH YOUR INSTRUCTOR who can demonstrate effects in real time. Forums are not the place to put your life at risk.

 

 

[facthunter]

safety & knowledge.

 

It's a fairly hard one, Turboplanner, and I share your concerns. This is an area where there seems to be some confusion around, and THAT is a bad thing. My advice has always been to do a bit of emergency manoeuver training with a qualified person in a suitable aircraft, but I doubt if anyone takes my suggestion seriously. Nev.

 

 

[turboplanner]

I wish they would Facthunter then some of them would not be leaving families behind for the sake of a few extra hours.

 

What concerns me is that this type of discussion seems to indicate that some Instructors are just going along for the ride, and doing immense damage in the process. If they were doing their job the question wouldn't be asked.

 

 

[shafs64]

Since i was the one who opened this can of worms.

 

I should say this. I have had good instructors and one who spent more time thinking of there forthcomming Job at the airlines. the person who tested me for my GFPT A very good pilot called John lindsey. showed me that best way was not to let the wing drop by keeping it all centre.

 

I still have less than one hundred hours and try to aviod stalls by flying the aircraft proply and if i want to go out and do stalls i will be talking a instructor with me.

 

Paul

 

 

[motzartmerv]

Turbo, your concerns are quite valid, but, if you read the threadstarters original post, he READ in a text book that aileron can be used to pick up dropped wings.... Books alone are not the answer and unless accompanied by good instruction can lead to more ambuguity.. So, like you said, talking it through and practising with an instructor is the go...:thumb_up:

 

 

[Guest Cloudsuck]

I'm just wondering what the point of using the forum is then.

 

Every time someone has a question about flying, do we all just shout "Ask your instructor"?

 

I thought that the original post by shafs64 was a good topic. He did not ask, "How do I do this and that" and not one reply was "You must recover from stalls (this way or that)". He was just trying to clear up the ambuguity in the topic. I'm sure he will seek good practical instruction and not rely on the forum members for instruction.

 

To me these topics are no different to the 'hangar talk' we will all be talking live tomorrow at the strip.

 

 

[Simonflyer]

Im Pretty new to these forums (and to flying in general), but surely the point of them is to gather as much information as possible, and then by working with our instructors, and perhaps discussing what we may have read here and elsewhere(books/training manuals/Mags etc), then we can by the combined experience of us all, become better pilots?..

 

I read a fantastic article (in the latest Australian Flying Magazine i think), about low speed flight, and how a lot of people are afraid to fly planes close to the stall speed, but they discussed that by spending time at those speeds with a qualified instructor, then you get a real feel for the plane at those speeds, and what signals and warnings you get coming up to and around the stall.Not just passing through that section of the training so we can get on with the "real" flying.They also discussed doing it at low level, as most fatal stalls of course happen close to the ground.Im not so sure i want to try that just yet, but it does make some sense..

 

Im waffling, so il stop here:loopy:

 

 

[bushpilot]

Bagging the use of forums to provide info on flying techniques is not productive... We should be encouraging everyone to put forward views, as this gives the less experienced readers some ideas to at least think about and then chat to their instructor about it.. Not all the views posted are going to be accurate (nor apply to all types of a/c), but at least they are thought starters - which is one of the reasons people use forums generally..

 

 

[turboplanner]

Views yes, unqualified "answers" and inappropriate "rules of thumb" no

 

 

[facthunter]

Qualification.

 

Chris, there many examples of "advice" and of behaviour that IF followed or imitated by "new chums" could be their undoing. A selected group of "mentors/experts". would have to constantly vet the information, and no doubt alter ,(or annotate it) to make sure their is no possible mis-interpretation. This would be an onerous and thankless task.

 

Forums, dealing with safety issues are not the place to run what is often opinion only, as fact, hence the oft-stated, TAKE IT TO YOUR INSTRUCTOR.

 

This MAY not be the solution, as he may not be very skilled in this particular facet of flying, and there may be good reasons for that (one being that RAAus aircraft are not permitted to do any unusual attitude work.) but, it is certainly not a BAD suggestion, as YOUR instructor should be aware of your interest and concern, as it may affect the way you fly. ( It is also good manners . The instructor has taken on a responsibility to make sure that the information and Training that you receive, can stand scrutiny and that can hardly be the case, if some of it comes from unverified sources, that he may not know about.) Early impressions are LASTING ones , and it is most important they are not wrong or confusing.

 

The initial question on this thread was a very valid one, essential to the safety of low speed flight. The enquirer has a right and a need to get an answer. The answer must be one that achieves the safest outcome, and I would have to say that a forum environment is not the optimum. How often has a carefully written statement been mis-interpreted? and people over-react to what they think is directed to THEM specifically when it is a general statement. This forum is possibly the best of it's kind and a valuable asset to us but it will never replace personal contact for getting your meaning across. Nev..

 

 

[Guest pelorus32]

[snip]In my Sierra with full flaps, the stall is quite sudden and the wing drop is large. It would be quite easy to enter a spin if you kicked in too much rudder while trying to 'Pick-up a wing'.

 

I should say this. I have had good instructors and one who spent more time thinking of there forthcomming Job at the airlines. the person who tested me for my GFPT A very good pilot called John lindsey. showed me that best way was not to let the wing drop by keeping it all centre.

And therein lies a little story which I think's instructive and goes to Nev's point about unusual attitudes training.

 

The Tecnam P92 is a benign staller in most situations. Slowly raise the nose, let the speed bleed off and it will mush and sort of stall with no real break.

 

But take the same aircraft and set it up in approach configuration with full flaps and a bit of power and then stall it. You get a very convincing break and smart wing drop - whether the ball is centred or not.

 

So the message is that if all you've been shown is common or garden stalls then you may not have seen what your aircraft is capable of. And if you've never gone up with an instructor and done aggravated stalls, including a nice little "turning final" stall (at altitude of course) then maybe that's a subject for your BFR.

 

Kind regards

 

Mike

 

 

[shafs64]

I have found that in a tecnam s2002 that it's very important to ge the trim right when on final or it can go outside VFE fast.

 

I have seen some training videos from the US where they teach full flap approch stalls something thats not done here i think.

 

Paul

 

 

[Mazda]

Personally I don't like the term 'pick up the wing with rudder.' I prefer to think 'keep straight with rudder' and look at a point on the horizon, using the rudder to stop the nose from yawing.

 

It is indeed possible to be in a stall and still flying (with a high rate of descent) and controlling direction by using the rudder, not the ailerons. As Nev said, do not "try this at home" without appropriate instruction, do a decent EMT course, it could save your life. Using aileron near the stall is not wise. It is true some aircraft are designed to have effective ailerons in the stall, but most do not and it isn't recommended.

 

Do an EMT course in a decent aerobatic aircraft with someone who knows what they are doing! It is only a few hours and you'll have fun learning.

 

 

[turboplanner]

Please note that the Shafs64 original post refers to a situation AFTER a stall, ie the AC has CEASED TO FLY.

 

The aircraft is about to drop like a hot rock, downwards.

 

The most immediate response is to get the nose where?

 

I'm mindful of a 2000 hour pilot - that's above the hours of many instructors, who stalled on turn to final, because he didn't identify that the stall speed would be vastly different at the speed and angle he was making his turn.

 

Incidentally there are currently 75 copies of the book I recommended available at US$9.75 from Amazon.com

 

That strikes me as a good investment.

 

 

[Bidgee]

I had long chat to an instructor about this about some time ago after receiving different instruction on stall technique. One wanted to use rudder the other wanted to use aileron. The argument against using rudder is that it is possible that an inexperienced pilot may in fact step on the wrong rudder and enter a spin. Especially the case if a pilot has most experience in an ac that drops, say, the left wing but they are flying one that stalls right wing first.

 

The instructor was more focussed on getting the nose down and throttle to the stop to regain flying speed.

 

Scott

 

 

[Mazda]

The aircraft does not cease to fly when it has stalled. It just has less lift. It will descend of course, but believe me, it will fly. It will turn as you wish, with very careful gentle rudder inputs, during the stall.

 

As I said, don't try this "at home", get some EMT instruction.

 

 

[motzartmerv]

Yes, thats right.. The CL max angle is the stalling angle of attack, the lift starts to to reduce on whats called the deadside of the curve ie after the stalling angle, and drag increases dramatically. So the bernouli function ceases but good old newton (action reaction) keeps on working.

 

Turbo, im not sure what you meant by "vastly different at the speed and angle he was making his turn"... The stall speed does NOT increase in a descending turn..If its the prang im thinking of, the guy got back to much on the stick in the turn to pick up the centerline (overshot the turn) and stalled for the same reason any other stall occurs, because the AofA was exceeded..

 

Another thing, i really don't like the term "lower ther nose" or, "put the nose where"... because in a propper stall the nose goes "where" anyway?...it drops, sometimes drops a lot, so if lowering the nose is drummed into you, and the nose is already lowered then what??.. relax back pressure, add power... Planes like the gazelle, you don't need to lower the nose, relaxing back pressure will get you out of the stall and the attitude may still be high, and still above the level attitude, with prompt power you can get away with 0 height loss and actually climb out of the stall....

 

 

[turboplanner]

Not too sure if it was the same accident Merv, but in this case I'm thinking of the pilot who was flying a high wing loading AC, hadn't been on it for some time, and pulled it round in a steep turn. We know that at about 60 degrees AOB the speed of the stall is almost doubled.

 

Merv and Mazda, you are talking about a transition, where there is partial lift occurring/aircraft self correcting.

 

If we split a sequence of stable flight > incipient stall > stall > stall recovery into 100 freeze frames the behaviour of the aircraft and corrective action will be quite different at frame 25 compared to frame 90, and you can see that both aileron and rudder can play a part when used at the appropriate time with the appropriate sensitivity, but you have to be able to identify which frame you're at, which action is best, and how much input is required to prevent over-correction.

 

Many people look for a simple answer, a "do this" or "don't do that", but it takes physical training and a build up of skill to be able to identify what's happening, and that's why I'm strongly recommending studying a book of nearly 400 pages put together by an expert who has maintained his expert status for more than 50 years, and going through the many stall scenarios with an RAA or GA qualified instructor who can demonstrate the sequence and the actions.

 

I agree, Merv and Mazda, that while there is relative wind flowing towards the flat surfaces on an aircraft there is some lift, and where there's lift there's the chance of control, but again you're talking about a part of the sequence.

 

For example, Mazda I note your aircraft is an Airtourer. In the 1960's I used to blow the cobwebs out of my mind by taking up an Airtourer once a week, climbing to 3500 feet and getting the COG above the centre of pressure, which usually meant pointing it at the sky on full power. As it ran out of speed it became unstable and fell out of the sky, sometimes backwards, sometimes falling on its back, sometimes tripping over a wing, and sometimes dropping over the nose.

 

Believe me, it mostly dropped like a hot rock, and the key requirement was to get it flying well before it reached VNE or 2000 feet, and it usually droped about 700 feet.

 

I should add the aircraft was rated for aerobatics and my instructor had taught me the sequence over several lessons.

 

In stick and Rudder, Langewiesche splits the sequences to show what is happening aerodynamically, spells out the many causes of stalls, explains how some aircraft stall more slowly (wing root stalls first, giving plenty of warning and being forgiving of aileron input until the stall reaches the ailerons, and how others stall without warning (wing tips/aileron area first), and how you need to condition your sub conscious when a stall occurs if you want to live another day.

 

There have been some suggestions that these forums are preferred rather than talking to your instructor. My answer to that is get out of that flying school; a good instructor is a mentor you will always look up to. If you can't communicate with your instructor, you'll pay thousands of dollars more, and may possibly even carry away a high risk factor through your flying career.

 

Taking advice on high risk activities from forums is like buying cancer cures from roadside market stalls. The person offering the advice may have good intentions, but may be less experienced than you, may be keen to air his views based on his lucky history, or may have misunderstood the question.

 

Take this thread for example:

 

The original question related to using aileron after the stall (and you'll note the Jim Davis background to his advice wasn't included)

 

There were posts discussing inputs near the stall, during the stall, comments (incorrect in some cases) on different aircraft, wing drop (where in some cases rudder is the best option), suggestions that rudder increases the chances of a spin (but no discussion on correct degree of input), talk of keeping the ball in the centre (call me unco-ordinated but I still have a problem doing that and all the other circuit work at the same time), "the Jabiru is a non event in a stall" (160 in a power stall?), quoted advice from an unidentified journalist who may never have been a pilot, which included a reference to practising stalls at low level (illegal and where the first adverse reaction would be dirt leaking through the door cracks), and publicising US full flap approach stall practice presumably on final approach.

 

Pilots who are on a learning curve will have difficulty deciding which of these posts are good advice and which are deadly.

 

It's interesting to see that people who have had long experience like MozartMerv, Facthunter and Pelorus are advising caution, study and communication with instructors on this complex subject.