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So........(sounds of crickets)...... pretty quiet around here lately


Guest Andys@coffs

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Hi Gnome , The" navigator", as detailed in her 'duty statement', is required to maintain a continuous supply of sugar free lollies at all times, particularly when coming into strips such as YSPT with 'fly neighbourly','displaced threshold','tree obstructions', 'preferred approach' ,'radio towers near turn onto final' etc.etc. . She chooses to place them on the Inst. console and this has worked very well over a number of years , however clearly this practice must cease ,as it appears that we are being held up to ridicule . I should also say that , in addition to not disagreeing with any decisions I make, it is one of her more important duties , and to change this long standing practice may take some time. kiss.gif.b85e4cbf93c012b498aab8fe7d5a5fe6.gif

Bob

No ridicule, Bob. I have a very similar picture taken on the way home from YTEM at Easter, and they were Easter eggs in my case. 020_yes.gif.58d361886eb042a872e78a875908e414.gif

 

 

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No flying till November 11th for me, but at least I'll finally be getting into circuits and making progress towards solo! Already managed to survive doing stalls, even though it goes against every form of common sense to yank back on the controls that far...

Hi there... keep at it and enjoy the experience ... but...

 

Why are you yanking on the controls to practice a stall?

 

Stalling an aircraft is - or should be - part of every flight. When you are rounding out 12" above the runway, the idea is to stall the aircraft on to the deck on the mains --- not to drive it on on the nosewheel. You aim to have the minimum forward speed possible and keep the nosewheel off the ground until it gently lowers as the forward speed diminishes even further.

 

Stalls at height are practised because it is relatively easy to be a little overloaded with engine management, circuit matters, other aircraft and the like when turning downwind on climbout or when turning base-final on approach and thereby allowing your speed to drop to a figure close to the stall at that angle of bank. Factor in an unbalanced turn and the intuitive raising of the nose with elevator because it has dropped in the turn and you have the makings of a stall-spin scenario. The powers that be hope that if you learn to stall by pulling the nose up 3000' off the ground this will somehow lessen the likelihood of you making a mess on their aerodrome.

 

Ask your instructor to let you bleed off speed slowly just keeping the nose on the horizon. Feel the aircraft start to wallow and balance it by using rudder to pick up the dropping wing. Learn to recover with minumum altitude loss using power and learn to recover with minimum altitude loss without power so you know what that is like should the situation arise. It's part of the fun and part of developing your skill set.

 

Many years ago it was compulsory to learn to spin an aircraft and recover it before you got your licence. Something changed along the way and many aircraft nowadays are placarded against spinning which means it's no longer an integral part of the syllabus. In my view, however, it is part of the best training you can undertake as a pilot and I absolutely recommend you spend a few hours with an aerobatics instructor in something like a Decathlon (or even a poor little Aerobat) to learn the basics. It's heaps of fun and it might just save your life!

 

kaz

 

 

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Probably should have chosen a better word than yanking! Trying to get across the fact of how hard it is to stall a foxbat, you can pull it to idle and slowly let the speed drop off and pretty much fly it on the point of stall for as long as you want, but to actually enter one you have to keep coming back on the yoke a fair bit from that point of stall, otherwise it's just buffet and not much else. Was trying to imply how going that slow and keeping on pulling back just goes against absolutely everything I'm thinking of in my mind!

 

 

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Stalling an aircraft is - or should be - part of every flight. When you are rounding out 12" above the runway, the idea is to stall the aircraft on to the deck on the mains --- not to drive it on on the nosewheel. You aim to have the minimum forward speed possible and keep the nosewheel off the ground until it gently lowers as the forward speed diminishes even further.

kaz

I agree with most of what you are saying Kaz... But not the stalling bit... I don't want my students deliberately stalling the aircraft onto the ground... I want them to fly level with the ground, raising the nose (increasing the angle of attack) as the speed bleeds off, until the inefficiencies of man and machine overcome lift and the aircraft settles to earth. In the case of my taildrager, we aim for the mains to kiss the ground, the tail will drop the last inch or two, the angle of attack will increase slightly but the speed is still deteriating, so the wing is producing less lift and the aircraft stays on the ground. Doesn't always happen that way of course. But that's what we're trying for.

 

Keep the sunny side up,

 

Wayne.

 

 

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A little bit different in the machines that I fly, Wayne. If the mains touch first it will almost certainly bounce. Mains and tail together or just touch the tail first. Either way, the attitude of the aeroplane is what it needs to be to achieve that. Sitting on the ground, the angle of the wings are much less than the stall angle.

 

 

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A little bit different in the machines that I fly, Wayne. If the mains touch first it will almost certainly bounce. Mains and tail together or just touch the tail first. Either way, the attitude of the aeroplane is what it needs to be to achieve that. Sitting on the ground, the angle of the wings are much less than the stall angle.

I've only ever been up in a Pitts once DJ. It was many years ago, and it certainly wasn't me who did the takeoff and landing... I'm told nasty things have been known to happen to folks who try to wheel them on... bounce.gif.3516b5f7197d1d6889168640af67e2f6.gif 067_bash.gif.26fb8516c20ce4d7842b820ac15914cf.gif

 

Keep the sunny side up,

 

Wayne.

 

 

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Guest davidh10
Probably should have chosen a better word than yanking! Trying to get across the fact of how hard it is to stall a foxbat, you can pull it to idle and slowly let the speed drop off and pretty much fly it on the point of stall for as long as you want, but to actually enter one you have to keep coming back on the yoke a fair bit from that point of stall, otherwise it's just buffet and not much else. Was trying to imply how going that slow and keeping on pulling back just goes against absolutely everything I'm thinking of in my mind!

That is just because you wouldn't do that in normal flying, but you are artificially inducing a situation that can occur in more normal attitudes under the right (wrong?) conditions.

Just yesterday, as I was turning base to land, in quite gusty conditions, the ASI dropped momentarily from 60kn to 45kn and I lost quite a bit of lift. It didn't stall although it was quite close and I could feel the instability, but had I been banking harder, it would have stalled momentarily. It only lasted a few seconds. If you have learned how to handle stalls, and practise from time to time, then it isn't a big deal and the reactions are automatic if and when it does happen. The wind on the ground was 12G19kn.

 

You should also learn stalls in a turn.

 

I wouldn't be stalling it onto the ground either. I want to be able to either execute a go-around from a height of one foot, if needed, or to just add enough power to hold off in ground effect to regain stability if a gust knocks me off line at the last moment. This is a real consideration in gusty cross-winds. I had to hold off and re-align yesterday, as did the instructor landing behind me. We were both hit by side gusts when within 50cm of touch-down.

 

 

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Sorry guys, I just edited my post #34. I was thinking about what djpacro said, so I went back and reread my post and DJ is right, "sitting on the ground, the angle of the wings are much less than the stall angle." So I was wrong to say the wing is stalled after touch down. The correct thing to say is it's producing less lift. Or perhaps; producing insufficient lift to continue flying.

 

Thank you for pointing that out to me as gently as you did DJ.

 

Keep the sunny side up,

 

Wayne.

 

 

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Sorry guys, I just edited my post #34. I was thinking about what djpacro said, so I went back and reread my post and DJ is right, "sitting on the ground, the angle of the wings are much less than the stall angle." So I was wrong to say the wing is stalled after touch down. The correct thing to say is it's producing less lift. Or perhaps; producing insufficient lift to continue flying.Thank you for pointing that out to me as gently as you did DJ.

 

Keep the sunny side up,

 

Wayne.

Hi Wayne and D.J,

I'm nowhere near as experienced as you guys, but I thought the angle of the wings (angle of attack) would become less relevant in tandem with the reduced airspeed to the point that it would make no difference at all ie. sitting on the ground you cannot calculate what angle is the stall angle without knowing the airspeed.

 

Hope that all makes sense and I'm not making a total fool of myself.

 

Regards Bill

 

 

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Hi Wayne and D.J,I'm nowhere near as experienced as you guys ...

No worries Bill, experience does not equate to being correct but there is an old saying:

“Old age and treachery will overcome youth and skill”

 

... Hope that all makes sense and I'm not making a total fool of myself.Regards Bill

It does indeed make sense. Noel Kruse's free book Fly Better #2 has an excellent explanation. He also just happens to use the Pitts as an example in his Figure 6 on page 31.

Figure Six is an external view of a Pitts S2S in the correct landing attitude just prior to touchdown. The fuselage is 12º from horizontal; therefore the wings, due to their incidence, are at an angle of attack of 13.5º, which is much less than their critical angle of attack.

Suggest start reading from Page 26.

 

 

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......Figure Six is an external view of a Pitts S2S in the correct landing attitude just prior to touchdown. The fuselage is 12º from horizontal; therefore the wings, due to their incidence, are at an angle of attack of 13.5º, which is much less than their critical angle of attack.

Hi DJP

Forgive me as I try to get my head around this.

 

An aircraft stalls when the airflow over the wings is at an angle that exceeds the critical angle;

 

From your quote above I can't stall the Auster while flying straight and level 12" off the runway because I can't get the tail down far enough to achieve the critical angle;

 

But this is predicated on the aircraft maintaining its straight and level flight whereas when landing it is actually descending because of decreasing airspeed hence decreasing lift;

 

The relative airflow is therefore not horizontal before touchdown but is at an acute angle directed towards the aircraft increasing the angle of attack accordingly;

 

My stick is all the way back on touchdown (in fact it's all the way back a tad before touchdown);

 

And that seems to me to put the aircraft much closer to the point of stalling at touchdown than suggested by the quoted passage.

 

I think perhaps what I should have said was: "The aircraft should be held off just above the runway for as long as possible while flown in the landing attitude as the airspeed/lift bleeds off. This requires the stick to be moved back progressively to avoid the nose dropping." ???

 

Or am I just dense?

 

At least whatever I'm doing seems to work ok.

 

kaz

 

 

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Your path is not horizontal, the aircraft is descending so the relative flow is upward and let's say the critical angle is 17 degrees, you can easily exceed this.

 

When the aircraft is sitting on the ground the chord angle from the horizontal is less than 17 degrees, but you're not flying then, you're not descending.

 

I got a lot of extremely smooth landings out of Cherokees with its sensitive stall warning just starting to chirp, so not quite stalled.

 

 

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Guest davidh10

While the relative airflow at touchdown is not horizontal due to the aircraft descending, it is pretty close.

 

Most light 3-axis a/c will fly final at a descent angle of about 3 degrees (just for interest, weight shift is about 6 degrees equating to about 500'/minute. About 800'/m for a glide approach) more than that is diving at the runway.

 

You definitely don't want to hit the runway at a descent rate of even 250'/minute (4.1'/sec). Once you hit ground effect and flare, the descent angle is going to be very small, otherwise you will have a hard landing. That being the case, for a normal landing and neglecting wind / gusts etc., then the descent angle is not going to be significantly different to that with a horizontal relative airflow once in ground effect.

 

 

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