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mazzy1026
16th Apr 2005, 20:35
Had an argument with a guy (none aviation) the other week, who said "yeah, landing is just a controlled stall" - I kind of didn't know what to say, other than I disagreed with him, yet I found that I couldn't quite explain it properly. My thoughts are that if you stall on landing, depending on which part, you can go down with a bump, and that you shouldn't exceed the 15 degree critical angle of attack :confused:

I feel that there may be mixed views on this, so I welcome any thoughts :ok:

Maz

DubTrub
16th Apr 2005, 20:43
mixed views Yes, there will be.

Lee, some landings are, some aren't, and there might be no rights & wrongs, too many variables in the landing appropriate to the aircraft type and/or the experience of the driver. As your Diary progresses (with your experience) and also after some experience in different types, you will become edumacated.

But your chap is wrong in generalising so much.

Rob

Genghis the Engineer
16th Apr 2005, 20:46
It's a controlled stall if you do it right - the aim being to stall a fraction after the mains touch the ground.

The word I'd dispute is "just" !

G

Monocock
16th Apr 2005, 21:23
"yeah, landing is just a controlled stall"

My view is that GENERALLY your friend is correct.

In nearly all cases (tricycle or tailwheel) the last second or two of a landing aircraft should involve the aircraft gently stalling onto the ground.

In a tricycle type this involves the mainwheels touching down and the P1 holding off the nose until it drops through lack of elevator influence. In a tailwheel configuration, the aim is to touch down all three wheels at the same time.

In certain conditions a tailwheel pilot will "wheel it on" which means he will be landing main wheel first (not stalled) and will then allow his groundspeed to decay enough for his airspeed to ensure that his tailwheel drops onto the ground. In this scenario he/she is not stalling the aircraft during landing.

On all cross wind "flares" I do believe that the aircraft is still stalled although it may well be with one wing down to counteract the drift effect.

To summarise, I still believeyour friend is correct.

DubTrub has a point however. I am not qualified to go into further detail on the areas I believe he is referring to. For the time being, I suggest you aim to stall your ship onto the hard and not do what too many do these days which is a flat "three wheel" splat that does nothing but keep Mr Front Oleo in the manner in which he ahs become accustomed.

Interesting thread, I'm interested as to how this develops

SquawkModeA
16th Apr 2005, 22:02
Landing your average, tricycle GA-aircraft (which is all I have experience from) should always be done stalled. The target will be to stall the aircraft as you touch down. Ideally you should be flying level so close to the runway surface that when you do stall you will touch down very gently, at the lowest possible groundspeed. Such a touchdown is very, very satisfying but happens rarely, at least for me.

You can go down with a bump, of course, but that's quite normal. All it takes is that you round out just a little to high and then when you stall you drop into the runway. That's not a problem. Indeed, you can easily make perfectly smooth landings by touching down with all three wheels at the same time, but that's obviously not a good landing. On the centerline, on the planned touchdown point and fully stalled - that's an excellent landing, whether or not you experience a "bump".

drauk
16th Apr 2005, 22:44
Should be: yes. Is: most certainly not always. Therefore to say a landing is just a controlled stall is incorrect. You can definitely land a plane without stalling it first - you just need the ground between where you are and where you were heading.

ChrisVJ
17th Apr 2005, 00:54
I would have said so, certainly I can get Jemima's nose high enough that there is an actual feelable 'break' when she drops that last foot, (OK , usually rather more) onto the runway.

BUT, if you think about it the usual effect is just that of pre-stall sink. Do you get buffeting? stick shake? do you have to use rudder instead of aileron to prevent wing drop? I don't, therefore I deduce that I am not actually stalling, just pronounced sink, which is good enough because clearly there is not enough lift to maintain height so she stays down.

n5296s
17th Apr 2005, 02:37
Depends on the type. Also somewhat depends on what you mean by "stall", since a stall isn't really an absolute thing but is actually progressive.

In a tailwheel plane doing a three-point landing, the answer is a pretty definite "yes". Of course in a wheel landing the answer is an equally definite "no" - the plane is very much still flying when the mains touch the runway.

In a high-wing tricycle plane, the answer is a definite "sort of". A nice landing in a Cessna is done with the stall horn sounding for the last second or two. However trying to land in a true stall attitude is a good recipe for a tail strike (guess how I know). And the stall horn sounds quite a bit before the wing actually stalls (obviously, or it wouldn't be of much use as a warning).

My experience of low-wing planes (Cirrus, Cherokee, Mooney) is that you want a flatter attitude than a stall - the plane is still flying at touchdown.

So I think the general answer is "it depends".

n5296s

A and C
17th Apr 2005, 07:50
A landing should not be made in a stalled condition as we all know as an aircraft stalls the C of P moves aft and the nose will drop out of control as all lift is lost. Roll control would be marginal to say the least ( within one or two knots of the stall most light aircraft can be rolled to the right with small amounts of left aileron & vice-versa) so recovering a wing drop would be interesting !.

The airspeed at the touchdown may well be below the normal stall speed but this is due to Ground effect and the aircraft is not stalled.

Once the aircraft is on the ground stalling the wing might be an advantage as the drag rise in a stalled condition will help slow the aircraft and the stalled wing will not be suporting the aircraft putting more weight on the wheels thus increasing braking action. Only aircraft with powerfull pitch control can take advantage of this so you can forget it in the PA28 but the DR400 and the PA38 can use this aerodynamic brake to an advantage on slippery runways.

Monocock
17th Apr 2005, 07:55
A landing should not be made in a stalled condition as we all know as an aircraft stalls the C of P moves aft and the nose will drop out of control as all lift is lost.

Without wishing to turn this into a debate, I disagree.

I do not believe that at a couple of feet above the ground with continuous back pressure to bleed speed that it is possible to get a nose drop. The aircraft will sink onto its mains well before the nose drops. Even when the wings have stopped producing enough lift to keep you in the air the elevator will normally be authorative enough to keep the nosewheel out of trouble.

Just my view

High Wing Drifter
17th Apr 2005, 08:30
I agree most with A & C. All you experience when landing is not enough lift to maintain height. The wing probably isn't at or past critical alpha. In my limited experience the stall warner may be sounding on some a/c in the flare, but the stall had yet to take place.

If the question is interpolated to heavies, then my personal interpretation of the theory is that the wing certainly isn't stalled on touch down!

I do disagree with n5296s a little. My understanding is that a stall is an absolute thing and is related only to the AoA, is measurable and has a defined constant start point for a set configuration; the critical AoA.

If the wing were near the stall with a wing down landing, would there not be a severe risk of a sudden wing drop on the up wing as the down aileron would effectively increase the AoA on that tip.

englishal
17th Apr 2005, 12:05
I tend to agree with Monococks understanding. In the rare event that I do a "greaser" the aircraft touches down with the stall warner buzzing, with a lot of aft elevator input. The elevator on most aircraft will retain authority even if the wing is stalled. Its important on some types not to relax back pressure too quickly as the nose will drop hard onto the ground (Seneca springs to mind) which is due to the aft CoP due to the stalled wing.

Stall recovery is often to "relax back pressure", and in types (and many others) like the PA28's, you can hold the aircraft stalled indefinitely (height permitting) with full back pressure, but keep a fairly level or slightly nose up attitude without it suddenly dropping until you relax back pressure.

Big jets have spoilers with spring up on contact with the ground. These have the same effect as stalling the wing I suppose (destroying lift).........

Just a humble opinion ;)

n5296s
17th Apr 2005, 15:59
I do disagree with n5296s a little. My understanding is that a stall is an absolute thing and is related only to the AoA, is measurable and has a defined constant start point for a set configuration; the critical AoA.

It's a handy simplification but not really true. There's a range of aoa during which airflow separation is taking place. Separation starts at the trailing edge and as aoa increases it moves forward along the upper surface, reducing lift. In addition the stall does not happen equally along the span of the wing - depending on flaps, washout, dihedral, stall-modifying devices such as fences and vortex generators. Thus there is quite a range of aoa where some of the wing is stalled but not all of it.

That said, from a pilot's perspective the plane stalls when you go over the hump of the C/L curve such that increasing aoa reduces lift rather than increasing it. That's what causes the nose to drop. But as another poster says, you can fly a plane in a fully stalled condition - you will lose altitude but it is completely controllable (sometimes called a "falling leaf"). It's an excellent exercise in control.

I suspect that in a "fully stalled" landing (e.g. in a taildragger) the wing is somewhat stalled but typically there is still some back elevator left - not much, but some.

John

FlyingForFun
17th Apr 2005, 16:50
My understanding is that, ideally, you should stall on landing. Especially so when 3-pointing a tail-dragger, but ideally a landing in a tricycle should be no different. (We'll disregard wheel-landings in tail-draggers for now, because they are completely different.)

I base this on the fact that, at the point of landing, I am unable to get sufficient lift from the wings to continue straight and level flight. Even if I move the elevator further back (and yes, in most aircraft I can still move the elevator further back) the amount of lift I get does not increase, and the aircraft settles onto the runway.

However, we all know that when we stall an aircraft, the nose will drop, sometimes sharply, and a wing may drop too. This doesn't usually happen when you land, fortunately. I've never had anyone give me an explaination for this which I like. The best explaination I have is that it's something to do with ground effect - ground effect changes the characteristics of the stall. Whether this is true or not, or how it works, I don't know, unless anyone else can explain it?

FFF
-----------

helicopter-redeye
17th Apr 2005, 17:25
Not in a helicopter .

Shaggy Sheep Driver
17th Apr 2005, 18:01
A correctly held off landing is a stall on to the ground in most aircraft. You keep pulling back with the mains an inch or so above the runway (ideally!) trying to prevent it from touching down (tailwheeler or trike, though many pilots of the latter don't bother) untill either you reach the back stop, or more usually the wing stops flying and the aeroplane sinks onto the main wheels at the absolute minimum possible speed. That's why the nose dosn't drop as it does in a stall at height - the mains releive the wing of any loading by touching down before things get that far. A (gentle) stall at height results in (initially) a high sink rate, followed by nose and maybe a wing dropping. When we perform a max performance fully held off landing (and except in strong and cross winds you always do don't you???), the touchdown happens during the very early stages of 'sink'.


SSD

BRL
17th Apr 2005, 19:29
How to do it properly........... (http://www.btinternet.com/~paul.evans28/Landing.WMV) ;)

ShyTorque
17th Apr 2005, 19:50
My normal landings are uncontrolled stalls........ but another 7,500 hours or so and I'm sure I'll crack it :p

mazzy1026
17th Apr 2005, 20:19
Thanks for all the great responses, I have been reading today and have been waiting for someone to mention "ground effect" - still a phenomenon in my mind, yet I think must have something to do with the landing, and how it is different from a full on stall.

When I practice a stall, I cut the power, hold the nose level, hold it, hold it, hold it, and this usually entails maximum pullback on the controls, just to keep the aircraft level (from which it eventually sinks and pitches forward). What I am trying to say is that, so far, I haven't been able to compare this stalling practice to a good landing, if you know what I mean, i.e I don't have to use full back pressure to stop the aircraft smacking the tarmac, just a significant amount to hold it gently as the aircraft slowly sinks. Having said that, occasionally I do hear the stall warner, especially flying dual due to the added weight.

I am starting to think that, after all, stalling is not an exact science, and can vary in lots of different ways, in different conditions, as already pointed out.

Thanks again (and for the vid BRL),

Maz :ok:

QNH 1013
17th Apr 2005, 20:26
I find it difficult to see how any aircraft I have flown could be stalled during the landing. As several people have pointed out, the stall occurs at the critical angle of attack, and all the tailwheel aircraft I fly sit on the ground at much smaller angle of incidence. Now, angle of attack depends on the direction of the airflow past the wing, but during the landing (i.e. in ground effect) it is difficult to see how this will be significantly different from horizontal unless the aircraft is decending very rapidly, certainly not something it should be doing in the flare.

I believe it was Alan Bramson who measured the angle of incidence (wing) of lots of tailwheel aircraft when they were on the ground, and concluded that the Dragon Rapide was one of the few that could be stalled in the three-point attitude.

I haven't tried pushing the tail of a Cessna 150 down to the floor to see if it could reach the critical angle of attack in an extreme nose-high landing, but I don't teach people to land at such an extreme angle anyway. As far as I can see, when I land an aircraft it is not stalled, and I don't want it to be.

Just think of the angle of the nose of the aircraft to the horizon when you practice a normal (1g) stall. You won't see the nose at anything like that angle to the horizontal when you are landing (I hope).

NB. I know purists will point out that the angle of incidence really refers to the angle of the wing wrt the aircraft, but in the above context I am using it wrt the ground for simplicity.

down&out
17th Apr 2005, 20:43
Well I can’t really comment on tail wheel a/c as I have never landed one. But I will have a go at this for nosewheelers:
However, we all know that when we stall an aircraft, the nose will drop, sometimes sharply, and a wing may drop too. This doesn't usually happen when you land, fortunately. I've never had anyone give me an explaination for this which I like.

As I said - a go at explaining things from my view point.

Firstly consider what happens in a normal stall in a normal a/c. The main wings are designed (for safety) to stall before the tail plane. This means they loose lift and the a/c roughly pivots around the tail plane.

Now consider this when the wheels are 1inch above the runway at the stall. The pivot takes place about the tailplane as above until the mainwheels touchdown. At this point a new pivot point is created - the mainwheels themselves. Then as the tailplane is not stalled it can continue to be used to alter the angle of the aircraft about the mainwheels. As the aircraft slows down the power of the tailplane diminshes until it can no longer provide enough downforce to keep the nosewheel off the deck - at which point it will lower, if you have not lowered it already.

Apologies if some techy terms are wrong, but the above seems to make sense to me & I would be interested in views on the principles of the above

A and C
17th Apr 2005, 21:54
D & A the aircraft will pivot around the C of G.

Now back to the stall thing now remember when you all first did your stall recoverys one of the things that the instructor pionted out to you was the pre-stall buffet.

Hands up who has felt that buffet on landing ?............guys without the buffet you wont get the stall.

n5296s
18th Apr 2005, 01:56
Further to my remarks about stalls... I was out doing airwork today in my TR182, and I tried using the ailerons (gently) in a full stall (yoke held fully back). As I expected (I've never tried before) the ailerons work normally. I didn't try full deflection since I didn't want to do a snap roll (or whatever it's called in the UK). In other words, although on aggregate the wings are stalled (past the peak of the C/L curve), the tips are not stalled. This after all is what they are designed to do.

I disagree with SSD's remarks about a stall at altitude - done correctly, you pull back and pull back, nailing the altitude, right up to the break, at which point there is nothing more to be done (except recover of course) - if you hold the stall at that point, you will get a highish sink rate and the nose will bob up and down, stalling and unstalling. But up to the break you can (pretty much by definition) hold altitude. Of course there are planes, such as the Cherokee, which have such a flat C/L curve that you never really experience a break even at full up elevator, so the only indication you have of stall is the sink rate.

n5296s

Blackshift
18th Apr 2005, 05:08
maz,

Remember that stalling with FULL FLAP, as is generally the case for a normal landing in most conventional training a/c, involves a much lower nose attitude due to the change in the effective chord line (i.e.leading edge to trailing edge) in this configuration.

Also, by attempting to continue to fly the a/c only a couple of feet above the ground with little or no power and NOT allowing it to sink onto the deck by raising the nose until the airspeed reduces to stalling speed, a fully developed stall can never really happen, since the aircrafts weight will simply settle on to the main wheels due to the negligible vertical velocity being attained by such a "stall", whilst the elevator should maintain enough authority - although some a/c require more than a trickle of power to achieve this - to gently lower the nosewheel onto the runway due to sufficient horizontal velocity being maintained.

Perhaps it may therefore be more appropriate to refer to an incipient stall on landing, since the stall has no chance to develop properly unless such a flare is attempted too high above the runway.

I think that the fear of this may be what encourages some instructors to let students and even PPL's away with shoddy fast three wheeler aircraft carrier type "arrivals". Sometimes the nosewheel is raised only very slightly for appearance just before impact - often resulting in the instant aversion therapy of an unwanted climb due to excessive speed, followed by hasty juggling of the controls to point the aircraft back in the right direction. So the student learns to fear the flare and just clatters onto the runway instead, sort of giving up and hoping for the best at the last moment, simply relieved that the runway finally appears to be in roughly the right place beneath and in front of him.

I have seen this very often, and not only with students.

Although not usually life-threatening, this is not exactly kind to the airframe, undercarriage, tyres and brakes - it is also a waste of perfectly good runway and often not very comfortable for passengers.

I once conducted a PPL check flight where the pilot did not appear to understand the concept of the hold off and flare at all, and was extremely resentful of my suggestion that his fast and flat landings could be improved upon, complaining that I was trying to re-teach him to land using some advanced technique as opposed to this method which he claimed to have been taught - but I suspect he had so far simply got away with. :hmm:

A and C
18th Apr 2005, 06:05
If the aircraft is about to stall do you feel the pre-stall buffet ? if on landing you dont the aircraft is not about to stall after all you teach buffet as one of the things that warns the student about aproaching the stall in the slow flight leasons.

Yes the aircraft may well be below stalling speed just before landing but this is due to ground effect IN MY OPINION the air that is accelerated between the ground and the bottom of the wing results in a low pressure area just aft of the trailing edge that "Sucks" the airflow down on the upper surface and prevents the break down of the upper surface laminer flow hence no buffet and no stall.

n5296s

Try the aileron thing with a PA38 and the roll responce will be quite different !

Blackshift
18th Apr 2005, 06:27
A and C,

Buffet, stall warner, low speed, unusually high aoa are all warnings of an impending or incipient stall - if the flare was too high there would undoubtedly be a perceptible buffet before the greatest loss of lift would be experienced. However, the buffet is surely at that stage of the stall-break where the airflow begins to seperate from the upper-surface and the lift threatens to decrease even more rapidly than before.

It has nevertheless decreased initially only slightly just at the back end of the lift/aoa curve in the case of a well executed landing, just enough to allow the mainwheels to settle on the runway - otherwise we would still be up there two feet above the runway.

In this case the stall simply doesn't have time to develop fully, due to the wheels taking the weight at almost the instant the aircraft reaches the back end of the lift/aoa curve, which is after all a curve, thus indicating a progressive rather than an instant occurance as the aoa is altered in the flare.

I suspect that we are not entirely in disagreement here, because I have already suggested that this is effectively reduced to an incipient more than a developed stall when done properly.

This is of course a matter of degree, rather than an absolute distinction:-

At the desirable end of the scale "greaser" is attained towards (but crucially just beyond - otherwise no descent!) the incipient side of the stall. I fully agree that ground effect might be of assistance in this process, especially in low wing a/c (the down side being that low wing a/c also have a greater tendency to "float" when the approach speed is too high), but that does not stop this from being a stall - it just becomes an even more progressive stall due to the delay in the breakdown of airflow above the wing, hence no buffet.

And at the less-than-desirable end of the scale, a collapsed undercarriage, or worse, would result from a fully developed stall with all the associated buffet and subsequent downwards acceleration you might expect as much of the lift is dumped from the wings after a continued attempt to flare too high above the runway.

High Wing Drifter
18th Apr 2005, 07:49
I was out doing airwork today in my TR182, and I tried using the ailerons (gently) in a full stall (yoke held fully back). As I expected (I've never tried before) the ailerons work normally.
Again, this is my understanding of the ATPL text. The ailerons may still work; straight wings generally stall at the root first. Generally speaking swept and taper wings stall tip first. I can imagine the problems created by a tip stall in the flare. Regardless, there is a theoretical danger (not managed to experience this yet) that the down going aileron will take the angle of attack beyond crit and stall the up going wing. May I refer you to my earlier comment on wing down landings?

Just to add, I witnessed the result of what I understand to be a stall in the flare this weekend - a PA38. Nose drop in flare, collapsed nose wheel...prop strike. Comments were made about the T-tail (not flown the type), beyond a certain AoA, being completely ineffective.

Blackshift
18th Apr 2005, 08:50
A and C,

Having just thought about this a little more I think you might be right about the a/c not being stalled...

It is of course the Coefficient of Lift versus Angle of Attack curve to which we are properly referring here. Lift is itself a function of air speed and density as well as CL.

It is in fact nonsense for me to suggest that it is necessary to achieve stalling speed for an a/c to descend onto its mainwheels.

I might well land a few kts too fast, not flaring as fully as I could and therefore allowing the flight path of the aircraft to descend such that although the main wheels make contact before the nosewheel, the downward momentum of the airframe is sufficient to cause the nosewheel to touch down immediately thereafter perhaps a bit more firmly than necessary or ideally desirable. Although not a "greaser" this might well be judged to be a fairly competent and safe landing.

However, a well executed "greaser" would involve flying just above (an inch/foot or whatever) the runway and gently easing the mainwheels onto the r/w in the following manner - the reduction in speed is hastened by increasing drag as aoa is increased to maintain just enough lift to maintain this marginal height until it begins to decrease gently at around stalling speed, due to the continuing reduction of airspeed for the max CL achievable as we approach the stall - there is therefore a small reduction of lift just at the instant we get to the top of the cl/aoa curve.

The buffet may begin to appear, albeit imperceptibly, as soon as the curve begins to descend. For some aircraft this can of course be a very sudden and perceptible occurrance, whilst others require stall strips to make it more obvious to the pilot. The point is that the rapidly reducing airspeed ensures sufficient loss of lift for such a landing before this occurs, therefore the aircraft cannot be said to be stalling.

It is however an incipient stall by every measure other than the buffet, which could be argued to be an initial symptom of a developing stall.

An aircraft can of course be stalled by attempting to flare at an unsafe height above the runway i.e. a height sufficient for the stall to develop.

HWD,

The PA38 does need a bit of power to maintain adequate elevator authority when landing. But elevator authority would surely be needed to stall the a/c, and as discussed above, if flared at a safe height a stall cannot develop.

If the accident was due to lack of elevator authority would it not be more likely to have simply been a nosewheel landing, perhaps following ballooning on finals and chopping the power?

mazzy1026
18th Apr 2005, 09:46
I am starting to come to the conclusion that the a/c is not stalled during landing. I have to admit though, I have had a couple of stalls where I didn't feel any buffet. Whether or not this was due to the fact that I was not performing it properly (is there a proper way? After all, a stall is something that is unwanted, and can happen if we dont pay attention). And what about the fact that the aeilerons dont produce much roll in a cross wind landing? (i.e. left rudder for direction, right aeileron for drift), they simply stop the aircraft from rolling?

Hope you can forgive my somewhat in-experienced knowledge :D

High Wing Drifter
18th Apr 2005, 10:19
Mazzy,

Can't say I've ever notice the buffet either. I think this must be something to do with not correcting the pitch quickly enough to prevent any sink until the stall. I will watch very carefully for this next flight.

Aussie Andy
18th Apr 2005, 11:04
It only isn't (a controlled stall) when I land too hard and too fast!

It also isn't when it the "controlled" stall occurs too high above the runway!!! In that case it's a controlled stall leading to a hard landing!

Andy :ok:

TD&H
18th Apr 2005, 11:17
MOST DEFINITELY NOT STALLED!!!

It is one of the most common errors people have about flying, including many who should know better.

As the above post re: Alan Bramson, very few tailwheel aeroplanes are in a stalled attitude on the ground. Just think how dangerous it would be if you did stall on landing, get it wrong by a few feet and a wing can drop, dig in and .... etc.

Do you honestly think a Jumbo (or any other airliner) has the stall warning going on landing? No is the answer. Stick shakers and stick pushers would be going mad, and positively stopping any pilot from trying to stall. They are flown on, then lift dump devices used, which put greater weight on the wheels for better braking, but still not stalling the wing.

How many pilots actually hear the stall warner going on a trike, C152, etc. when landing? Not many, and even if they do, they're still not stalled, only close to it.

So your landings are not controlled stalls, just a case of not providing enough combination of speed/lift to maintain horizontal flight, so you're descending at a slow enough rate for the gear to take the load, then roll out.

n5296s
18th Apr 2005, 18:00
Again, this is my understanding of the ATPL text. The ailerons may still work; straight wings generally stall at the root first. Generally speaking swept and taper wings stall tip first. I can imagine the problems created by a tip stall in the flare. Regardless, there is a theoretical danger (not managed to experience this yet) that the down going aileron will take the angle of attack beyond crit and stall the up going wing. May I refer you to my earlier comment on wing down landings?

Indeed. I wasn't tryng to say that all planes will behave like this, just reinforcing the point that a stall isn't an "all or nothing" thing. In my plane (Cessna TR182), evidently the wingtips are unstalled - as evidenced by aileron effectiveness - even though the net situation is a stall (i.e. increasing aoa reduces lift). Your comment about the aileron taking the wing beyond critical aoa is a valid one and the reason I didn't try an abrupt aileron deflection, since the 182 isn't an aerobatic aircraft and I didn't want to try doing snap rolls in it. (A snap roll is done by simultaneously stalling the wing, yawing towards one wing and trying to bank away from it, developing a very deep stall on one wing and unstalling the other, giving a very high rate of rotation).

While swept wings naturally stall at the tips first (for reasons I honestly can't remember), designers go to a lot of trouble to avoid this. That's why airliners have such huge amounts of washout (differential inboard aoa) together with various other tricks such as stall fences.

As for the Tomahawk, what can I say. Sounds like Darwin will soon have dealt with the fleet. I've never heard anything about it that would make me want to fly one.

Oh and one other thing... the buffet thing. High wing Cessnas show almost no stall buffet, so it\'s not surprising that you don\'t feel it on landing. However the Pitts has LOTS of buffet close to the stall, and you don\'t feel it even on a tailwheel landing. Which tends to suggest that even that isn\'t stalled at landing.

n5296S

High Wing Drifter
18th Apr 2005, 18:47
This is definately one of those aviation topics that improves proportionally to the amount of beer drunk.

One for the fly in? Maybe a demonstration is in order :E

Blackshift
18th Apr 2005, 19:03
As for the Tomahawk, what can I say. Sounds like Darwin will soon have dealt with the fleet. I've never heard anything about it that would make me want to fly one.n5269s,

The PA38 recorded a fatal accident rate of 0.55 per 100,000 hours between 1980 and 1999, which is better than any other single engine aeroplane, so it can hardly be considered to be some sort of deathtrap.

The next best was the PA28 at 0.76, followed closely by the C172 at 0.79.

The C150/152 comes in behind the PA25 Pawnee (0.85) at 0.94 fatal accidents per 100,000 hours.

This came as quite a surprise to me, having flown a PA25 as a glider tug (probably its most common role in the UK) and considering this to be perhaps a bit more dangerous than most of the other flying I have done.

Having instructed on both types, I think it is possible that the more pronounced stall/spin characteristics of the PA38, compared to the 152, encourage people to treat it with a bit more respect, and accordingly to fly more safely.

Aeroplanes bite fools irrespective of how benign their stall characteristics might be, or how difficult they are to spin.

In any case, as well as having much better visibility in the turn, the Tomahawk is also much more comfortable than the 152 for the more generously proportioned amongst us.

Think again.

A and C
19th Apr 2005, 07:04
I should be a bit carefull about what you read in the ATPL books while being not untrue the facts are so genralised by the burocrats that they have only a passing resmbelence to the real world once you have your licence to learn the real education will start.

High Wing Drifter
19th Apr 2005, 08:10
It was me who mentioned that my 'knowledge' is from an ATPL course and that is why I mentioned it - to ensure that it was in context and that I wasn't writing above my station (so to speak). However, so far experience has, more or less, matched the course. I remain open minded (honest).

Shaggy Sheep Driver
19th Apr 2005, 17:23
TD&H

Airliners do not normally carry out fully held-off landings. We are talking about light aircraft here.

If I hold off a tad high in the Chippy, the aeroplane reaches the 3-point attitude and then (despite my still holding the stick back)drops onto the ground with a jolt. What's that but a stall?

The moment the wing stops flying can be felt, and swift application of a trickle of power will cushon the impact. But if you just sit there it can be quite teeth-jarring. :eek:

SSD

SpinSpinSugar
20th Apr 2005, 16:52
Have always found the Tomahawk to be a great aircraft to fly, very reponsive and far easier to land well than high wing Cessnas. But maybe that's just me.

Regarding the stall warning horn, very rarely with the Tomahawk and semi-regularly for a 172 if there's a nice smooth touchdown involved, you seemingly have to hoik the nose a lot higher in that type to avoid a hard landing. By stall warning I mean just a little chirrup from the thing a fraction before the wheels touch.

When practicing stalls in either type it seems as though the warning sounds a long way before a proper stall develops so I doubt I've ever been close to touching down in a properly stalled condition.

But then I could be wrong, interesting posts in this thread from those wiser than oneself!

Cheers, SSS

Ringway Flyer
20th Apr 2005, 20:20
Stick & Rudder, chapter 16. 'Nuff said...
:ok:

andrewc
21st Apr 2005, 01:01
No..it isn't...!

-- Andrew