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Old 12th Mar 2013, 17:51
  #21 (permalink)  
 
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My 02 cents:

- IMO the Maule is pretty much a technique optional airplane when it comes to the T/O. A regular tail low take off with 24 deg flaps is already so short if the field needs some sort of hero move like popping flaps to get it off, than you probably should not be trying the takeoff.

-For regular Cessna/Piper aircraft the POH recommended take off flap setting ( ie flaps 10 to 20, depending on the model for the Cessnas, one or two notches for the Pipers) and establishing a nose high takeoff attitude which has the nosewheel clear of the runway works fine. The idea that you start with no flap and then add the 10 or 20 during the takeoff run is another flight school urban myth propagated by folks who don't have any real world experience. It doesn't make any difference and distracts the pilot.

- The most important thing when dealing with soft surfaces is to have a predetermined abort point. Many pilots have run into trouble when they find the airplane will accelerate to some speed that is less than you need to lift off and then refuse to accelerate further. They continue the takeoff hoping the airplane will accelerate but it never does. if you are very proficient then going to full flaps when the airplane won't accelerate can result in the aircraft ballooning into the air. But the airplane will lift off semi stalled and some very accurate flying is needed to accelerate in ground effect while raising the flaps without stalling or sinking back onto the runway.

Last edited by Big Pistons Forever; 12th Mar 2013 at 23:16.
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Old 12th Mar 2013, 23:06
  #22 (permalink)  
 
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i feel for those who have never experienced the feel of soft grass under their wheels on landing, or the thrill of liftoff from a far from level gravel/sand/grass runway, the satisfaction of stopping in 100mtrs on a 120 mtr long one way strip.
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Old 13th Mar 2013, 01:42
  #23 (permalink)  
 
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pb84,

Nice work. I hope your nephew was dressed warmly. -2 C in the Glens O'Angus must be a bit cool!

Good choice to fly with the sun behind you

"Contaminated runway settings" in a Maule AFM? If everyone followed F900 Ex's advice, there would be little or no bush flying in many parts of the world.

There is a Transport Canada publication called Light Aircraft Operating Tips (TP 4441E). Surprisingly, it doesn't seem to be available on line, but it is quoted in a very sad accident report here:

Aviation Safety Letter 2/2000 - Transport Canada

The publication suggests that the take-off ground roll should be increased by 10% for a runway surface that is rough, rocky, or covered with short grass (up to four inches). It further suggests that the ground roll should be increased by 75% or more for a runway with a soft surface (mud, snow, etc.).
PS I tried to post this reply yesterday, but for some reason it did not work. Since then the conversation has moved on and I see that F900 Ex's posts have now been deleted.
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Old 13th Mar 2013, 14:19
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The idea that you start with no flap and then add the 10 or 20 during the takeoff run is another flight school urban myth propagated by folks who don't have any real world experience
Can't say I ever encountered the technique at 'flight school'.
I must have perfected it during the subsequent 30 yrs experience in the real world.


Watch the flaps.

Last edited by Flyingmac; 13th Mar 2013 at 14:38.
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Old 13th Mar 2013, 14:46
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Piperboy84 technique of bouncing the aircraft into the air with flap just before rotation DOES work.

I have never heard using full flap though, but as I've previously said, I have no experience on Maule's.

I was never taught the flap trick during training, but learnt this from a test pilot on an air test. I was amazed and have adopted this method myself just a few times.
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Old 13th Mar 2013, 15:38
  #26 (permalink)  
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RW
Piperboy84 technique of bouncing the aircraft into the air with flap just before rotation DOES work.

I have never heard using full flap though, but as I've previously said, I have no experience on Maule's
I probably did not make this clear, I do not use full flaps on the video, My flaps are as follows
1st Notch= -7 deg for Cruise.
2nd Notch = 0 deg (Neutral)
3rd Notch= 24 deg for Take off
4th Notch= 40 Deg = landing (base turn)
5th Notch= 48 deg= landing (short final)

I start the initial roll with TO flaps (24) then just prior to lift of I pull on 40 deg, but do not release my thumb pressure on the flap button and just hold in the 40 deg till clear then slowly reduce back to the 24 deg notch, from watching the video I believe i relaxed the flap handle back from 40 to 24 to early and also did not lower the nose quickly enough to stay in ground effect to allow speed to build, and that is why i think i got the drop.

Better luck next time.

(An afterthought edit)

BPF’s point about having a predetermined fixed decision/distance marker for attaining full lift of speed is noted, I was using about 200 feet of a 1600 feet strip and predetermined that if I had not reached 70% of my TO speed by 50% of the strip I would abort, however I did not give equal prior consideration to where my abort point was if after attaining 70% no further speed was forthcoming, and I suppose I left that up to deciding on the fly which is probably not the best way to go.

Live and learn.

Last edited by piperboy84; 13th Mar 2013 at 16:17.
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Old 13th Mar 2013, 16:16
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Piperboy 84

Ah, that makes more sense now, thanks for the heads up on the Maule
flap settings.

When I read your earlier post, which has now changed to post #13,
I saw reference to 40 degrees/ landing flap and took this as full flap,
my apologies. The variants that I fly, both single and twin are 40 degrees = full flap.

I would never initiate the pulling flap at rotation discussion on here, in fear of getting flamed out, but it does work, and should be demonstrated by an experienced competent pilot, as it was to us.

One other thing, don't rely upon luck!

You and many others have now seen what could have happened. Go and practice releasing the 4th notch and holding ground effect. You will be surprised the more you practice, the luckier you will get!

Safe and happy flying.
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Old 13th Mar 2013, 17:51
  #28 (permalink)  
 
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Obviously starting a takeoff roll with flaps extended will mean you are pulling against a certain amount of drag for the whole takeoff run.
There is an argument that leaving the aircraft clean until near rotation speed will mean that the takeoff run will be shorter.
There are a couple of negatives
1
Obviously you are now on your own as Manufacturers will not publish takeoff data for clean runs with flap extended near rotation.
2
This adds an extra distraction and extra room for making an error.
3
This requires precise handling
4
Question whether that reduction in drag is worth the other risks ie if it only saves a few feet!

Going back to the original question re snow? There are numerous variables which make snow takeoffs imprecise.

How deep is the snow? Is it fresh snow or frozen into sheet ice below the powder covering? Is it dry powder snow or slushy porridge like snow.
(any skier knows how snow can change from solid ice to porridge over the course of a few hours.

To a certain extent you are in the realms of test pilot so an absolute no no on minimal runways or landing strips!
Have an abort point with plenty of stopping distance left if the aircraft is not accelerating as it should be.
Landing go steady and be smooth on braking action any doubts on the surface go around

Pace
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Old 13th Mar 2013, 18:32
  #29 (permalink)  
 
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my limited understanding of the flap popping technique is that it is most valuable in a soft field environment where you are nose high for most of the takeoff roll. In this position you are generating material lift (and hence material induced drag) for much of the takeoff roll. Having more flap out increases the low lift and induced drag (and increases some, but probably not a lot the induced drag). So overall you get a material benefit from no flaps (minimising drag while you accelerate) and then 'suddenly' generating enough lift to get into ground effect clear of the retarding effect of the soft field.

I would have thought it would have a very marginal impact on a nose wheel aircraft rolling down the tarmac with a very low natual AoA.

Just a point on the '70% speed by 50% of the runway' - there are a reasonable number of conditions that can result in not obtaining takeoff speed by the end of the runway from the 70% point. If you are only at 70%, the best you are going to achieve is take off right at the end of the runway.
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Old 13th Mar 2013, 18:48
  #30 (permalink)  
 
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I have a friend who has a theory on pretty much everything. He normally flies a C182 and hits the flaps down two detents at about 25kts. That's fine in the C182, but put him now in a C150. Same trick hits the flaps without looking at 25kts, not realising they will cycle all the way down to 40 deg droop...... Seen him do it and he had no idea that he would be stuck in a bush if I hadn't copped his mistake.

Manual flaps are an excellent tool for STOL ops. Foostering with electric ones is not worth the hassle, just set them and go. Nice vid's of the Maule btw. They are a cool as airplane in my books.

Irish
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Old 13th Mar 2013, 19:49
  #31 (permalink)  
 
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Dropping flap on a C182 is surely a joke. They are so slow you would be at 1000ft before they got to 20deg.

I agree about the Maule. I'd love an aircraft with a name like Lunar Rocket!

D.O.
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Old 13th Mar 2013, 20:47
  #32 (permalink)  
 
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Husky one of my dream machines

I was told a test pilot pulled the nose up kicked in right rudder at the stall and whacked in full power and the thing clawed its way back into flight
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