PA-28 short field take off flap setting
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stick pulled back to the max. - let go of the brakes and just wait until whatever speed the aircraft is of the ground, I agree on the PA 28 it will not be 35 kts, it will be a little higher, however this is what will get you fastest of the soft ground.
As I mentioned, in a PA28, you can be off the ground, and stuck in ground effect. You will certainly not anything close to the best short field performance (and that is what this thread is about). If you don't get out of ground effect, you better either have a place to land right ahead, or be able to retract the landing gear (the only thing that saved us!).
I have mentioned the flap technique only with reference to float flying in Cessna 180/185, where generally takeoff distance available is not a factor, and striking the tail on the ground is not possible! My personal experience is that fiddling with the flaps on the water can help, but simply lifting one float out first is much more beneficial, and much less dangerous.
A short field takeoff is about getting off the ground and over an obsticle in the shortest distance along the ground.
A soft field takeoff is about getting off the ground at the lowest SAFE airspeed. It is possible to be off the ground at less than the safest airspeed, why would you want to do that? You'll bang the tail, and settle back on in less than full control! We're only talking about SAFE flying techniques here right?
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Short field
The purpose of holding full up elevator and max power against the brakes is to exploit the slipstream over the tailplane enabling a reduction of the weight of the nose wheel. You must remember though that the increased downforce from the tailplane ADDS to the weight of the aeroplane. As the aircraft accelerates the back pressure should be relaxed (not as previously described) trading off the increased downforce (weight) with the reduction of drag from the nose wheel. Holding full aft stick throughout will increase the take off run, not shorten it.
Holding full aft throughout the take off run prevents the aircraft becoming lighter and raises the angle of incidence towards the stall and increases induced drag. There has been much talk about being stuck in ground effect. Much more likely that the aircraft is stuck in 'the gate' of the imminent stall and an inability to lower the nose without setting back once more on the runway. All too often we read of aircraft impaled in trees along the climb path for this reason. Remember that an aircraft will only climb when power/thrust exceeds drag. Increase drag and the aircraft will climb less and to a point that it will not climb at all.
Holding full aft throughout the take off run prevents the aircraft becoming lighter and raises the angle of incidence towards the stall and increases induced drag. There has been much talk about being stuck in ground effect. Much more likely that the aircraft is stuck in 'the gate' of the imminent stall and an inability to lower the nose without setting back once more on the runway. All too often we read of aircraft impaled in trees along the climb path for this reason. Remember that an aircraft will only climb when power/thrust exceeds drag. Increase drag and the aircraft will climb less and to a point that it will not climb at all.
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r mr tigger are you a winnee the pooh fan or do you have a triumph or AA5 
any how sounds about right from my memory which is somewhat eroded by time . what we do; what we did ;what we teach ;are not the same the pa 28 ./22 cessna are not the same;140 /180and warrior151/161 are not the same.we all learn little tricks. but not always best for low time people or the poh .legal bit.did a bit 140 t/o landing 8min pleasure flight sectors.tried it all but the book technique is fine,and if it don't work how or why did you put the a/c there to start. or is that back to the lorry scenario, and for something more serious lets not confuse short or soft or any combination of .(although i seem to suffer from both or so the wife says)
homegard gates of flignt was that by?Wollf gang smit?? and lets share our experience not bicker
any how sounds about right from my memory which is somewhat eroded by time . what we do; what we did ;what we teach ;are not the same the pa 28 ./22 cessna are not the same;140 /180and warrior151/161 are not the same.we all learn little tricks. but not always best for low time people or the poh .legal bit.did a bit 140 t/o landing 8min pleasure flight sectors.tried it all but the book technique is fine,and if it don't work how or why did you put the a/c there to start. or is that back to the lorry scenario, and for something more serious lets not confuse short or soft or any combination of .(although i seem to suffer from both or so the wife says)homegard gates of flignt was that by?Wollf gang smit?? and lets share our experience not bicker
Last edited by much2much; 3rd Apr 2009 at 20:05.
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The purpose of holding full up elevator and max power against the brakes is to exploit the slipstream over the tailplane enabling a reduction of the weight of the nose wheel. You must remember though that the increased downforce from the tailplane ADDS to the weight of the aeroplane. As the aircraft accelerates the back pressure should be relaxed (not as previously described) trading off the increased downforce (weight) with the reduction of drag from the nose wheel. Holding full aft stick throughout will increase the take off run, not shorten it.
Holding full aft throughout the take off run prevents the aircraft becoming lighter and raises the angle of incidence towards the stall and increases induced drag. There has been much talk about being stuck in ground effect. Much more likely that the aircraft is stuck in 'the gate' of the imminent stall and an inability to lower the nose without setting back once more on the runway. All too often we read of aircraft impaled in trees along the climb path for this reason. Remember that an aircraft will only climb when power/thrust exceeds drag. Increase drag and the aircraft will climb less and to a point that it will not climb at all.
Holding full aft throughout the take off run prevents the aircraft becoming lighter and raises the angle of incidence towards the stall and increases induced drag. There has been much talk about being stuck in ground effect. Much more likely that the aircraft is stuck in 'the gate' of the imminent stall and an inability to lower the nose without setting back once more on the runway. All too often we read of aircraft impaled in trees along the climb path for this reason. Remember that an aircraft will only climb when power/thrust exceeds drag. Increase drag and the aircraft will climb less and to a point that it will not climb at all.
Very valid point! Pilots who hold the column back waiting for the aircraft to fly off are actually extending their takeoff roll. The only reason to do this is on rough bumpy strips where the pilot needs to get the nosewheel away from the ground. But it is another misconception that it is your quickest way off the ground.
I can remember flying a Seneca off bumpy grass and the aircraft launching off a particular bump before she was ready to fly. I was flying below the published stall speed. I believe another Seneca carrying a famous horse jockey crashed in a simular situation with a wing drop and subsequent crash killing some of the occupants.
Speed is your friend drag is your enemy.
Pace
Last edited by Pace; 3rd Apr 2009 at 22:50.
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Crikey! How many different opinions by the chest banging thousands-of-hours brigade! here are my observations for what they are worth......
This is the RECOMMENDED short field technique in my POH. My aircraft only uses "take off flap" though. I agree with the "New" bit though, best practiced on a long runway until competent.
Every PA 28 I have flown used 2 stages (25 deg) of flap as the RECOMMENDED s/f take off technique. Using less and you are not using the RECOMMENDED POH procedure and it won't give you the POH uoted perfomance.
When doing a soft field take of, I hold the stick back and full power - once I have seen airspeed is alive, then I don't look at it again, when the aeroplane wants to fly it will fly. As soon as it is in the air, I lower the nose and fly along the runway a few feet up in ground affect to accelerate before climbing away.
Finally, Ernest K Gann avoided the Taj Mahal in India by selecting full flap after take off. His plane was severely overloaded (unbeknown to him) and wasn't climbing away with the Taj on the nose. Just before "impact" he selected full flap which enabled him to balloon over the TM, before slowly climbing away. So do whatever it takes, if there is a fence at the end of the field, are you going to go full flap or just hit it? I know which I'd do
Changing flap settings during takeoff introduces simulaineous distraction, and change in flying qualities, neither of which are appropriate during a takeoff by a pilot who is new, or new to type.
Every PA 28 I have flown used 2 stages (25 deg) of flap as the RECOMMENDED s/f take off technique. Using less and you are not using the RECOMMENDED POH procedure and it won't give you the POH uoted perfomance.
When doing a soft field take of, I hold the stick back and full power - once I have seen airspeed is alive, then I don't look at it again, when the aeroplane wants to fly it will fly. As soon as it is in the air, I lower the nose and fly along the runway a few feet up in ground affect to accelerate before climbing away.
Finally, Ernest K Gann avoided the Taj Mahal in India by selecting full flap after take off. His plane was severely overloaded (unbeknown to him) and wasn't climbing away with the Taj on the nose. Just before "impact" he selected full flap which enabled him to balloon over the TM, before slowly climbing away. So do whatever it takes, if there is a fence at the end of the field, are you going to go full flap or just hit it? I know which I'd do
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POH procedures suffice to achieve POH performance. In other words, the more advanced techniques are only required if you need to make flights that the POH says are not possible. I rarely have that requirement, so I end up sticking with that unimaginative POH method... Admittedly, I don't fly floatplanes.
The other stuff seems like fun tho'! I won't try it!
The other stuff seems like fun tho'! I won't try it!
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As another old lag who's been flying PA28s for far too long, I can see the point behind most of the posts above.
I was taught that for soft field, don't stop and rev against the brakes. Set two stages of flap (ie not the third, drag flap). Keep moving, feed in the power smoothly as you line up, keep the weight off the nosewheel but not with full up elevator, and accelerate in ground effect. That will work for any pilot, and there are graphs that tell you how much take off run and distance over a 50 foot wall you need. They seem to work, with the standard adjustments for wet grass, tailwind, etc.
HOWEVER ... I fly an Arrow (taper wing), and that has a CAA note in the POH recommending that flaps are not to be used for takeoff. I'm glad it's only a recommendation (not a mandatory instruction) because getting out of grass strips would be extremely difficult without flaps. Two stages, set before the takeoff run starts for me - I'm not good enough to cope with pulling flap while accelerating.
I was taught that for soft field, don't stop and rev against the brakes. Set two stages of flap (ie not the third, drag flap). Keep moving, feed in the power smoothly as you line up, keep the weight off the nosewheel but not with full up elevator, and accelerate in ground effect. That will work for any pilot, and there are graphs that tell you how much take off run and distance over a 50 foot wall you need. They seem to work, with the standard adjustments for wet grass, tailwind, etc.
HOWEVER ... I fly an Arrow (taper wing), and that has a CAA note in the POH recommending that flaps are not to be used for takeoff. I'm glad it's only a recommendation (not a mandatory instruction) because getting out of grass strips would be extremely difficult without flaps. Two stages, set before the takeoff run starts for me - I'm not good enough to cope with pulling flap while accelerating.
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The safest way of getting a heavy PA 28 out of a short field is on the back of a lorry!
Speed is your friend drag is your enemy.
Both can be your enemy as can ignorance
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I love a good argument!!! I THINK that the differance in acceleration to agiven speed with/with out first stage flap will be VERY small, slightly slower with flap. I THINK the point being missed is that in the air (flying) full flap will be high drag and slow you down, however when running along the ground SUDDENLY dropping full flap will "trap" a pocket of air and push the 'plane up in to the air much below "normal" flying speed. The drag will be less than experianced in the air as the speed is much lower and in ground effect, once in the air the last stage of flap will need to be removed to let the 'plane accelerate. The reason I THINK it will not work with electric flaps is because they don't drop quick enough to "trap" the air.
These are just my thoughts, I have only ever flown about 5 1/2 hours PUT so what do I know
I THINK that the differance in acceleration to agiven speed with/with out first stage flap will be VERY small, slightly slower with flap. I THINK the point being missed is that in the air (flying) full flap will be high drag and slow you down, however when running along the ground SUDDENLY dropping full flap will "trap" a pocket of air and push the 'plane up in to the air much below "normal" flying speed. The drag will be less than experianced in the air as the speed is much lower and in ground effect, once in the air the last stage of flap will need to be removed to let the 'plane accelerate. The reason I THINK it will not work with electric flaps is because they don't drop quick enough to "trap" the air. These are just my thoughts, I have only ever flown about 5 1/2 hours PUT so what do I know
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I have only ever flown about 5 1/2 hours PUT so what do I know
The correct technique is to follow the advice in the manufactures current manual as approved by the CAA.
As well as common sense this is the answer to give the prosecution barrister at your trial if you do go though the hedge and survive.
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One problem I have come across is that many instructors fly C172's and PA28's. The C172 uses 10 deg of flap and the (most if not all) PA28 25 deg for s/f. Most instructors can't be bothered to read the POH and hence don't know this. I just about had a row with a FI early on in my flying when doing a s/f take off in a PA28 from a grass airfield...he insisted I use 10 deg, I said that we should use 2 stages, and of course after a discussion at the end of the runway he "won" being the more experienced.....and we survived.
I've also known instructors crash headlong into a mountain and kill themselves, so the moral of that story is that don't just accept what they say if you have any doubt, no matter how experienced they think they are (this goes for anyone, not just FI's of course).
PS I was right, I read the POH later.
I've also known instructors crash headlong into a mountain and kill themselves, so the moral of that story is that don't just accept what they say if you have any doubt, no matter how experienced they think they are (this goes for anyone, not just FI's of course).
PS I was right, I read the POH later.
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Take-off flaps
Having seen so many differing opinions I thought that I would re-visit my old Rallye MS880 POH---I quote`` operation on short runways --set progressively to full RPM while the brakes are applied,Extend the flaps to 30degrees at VI 32 kts.As soon as the aircraft lifts off,set VI 62 kts: then retract the flaps progressively while reaching the climbing speed.``This is using 30 degrees of barndoor flaps wih only an O-200 up front.It works but obviously attention to stall characteristics is crucial.Same instuctions in my 180 hp MS 893 but slightly higher speeds
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The observation about the recommended technique for the Rallye is interesting, and well supports the importance of reading the recommended procedures for the aircraft type you're flying, as there are many differences. There are certainly enough differences between the aerodynamics of a Rallye wing and a PA 28 wing, and the intended type of slow flight handling for these two aircraft, to make the recommended techniques and "apples to oranges" discussion.
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r mr tigger are you a winnee the pooh fan or do you have a triumph or AA5 any how sounds about right from my memory which is somewhat eroded by time . what we do; what we did ;what we teach ;are not the same the pa 28 ./22 cessna are not the same;140 /180and warrior151/161 are not the same.we all learn little tricks. but not always best for low time people or the poh .legal bit.did a bit 140 t/o landing 8min pleasure flight sectors.tried it all but the book technique is fine,and if it don't work how or why did you put the a/c there to start. or is that back to the lorry scenario, and for something more serious lets not confuse short or soft or any combination of .(although i seem to suffer from both or so the wife says)
homegard gates of flignt was that by?Wollf gang smit?? and lets share our experience not bicker
homegard gates of flignt was that by?Wollf gang smit?? and lets share our experience not bicker
Pardon?
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Yet another
For the PA-28-161---
Two stages of flap. Back pressure to maintain some weight off the nose wheel.
AS soon as it's off, stay in the ground effect until you get the speed you need.
Then climb away.
With one stage of flap it doesn't fare well in a certain grass strip.
1/60
Two stages of flap. Back pressure to maintain some weight off the nose wheel.
AS soon as it's off, stay in the ground effect until you get the speed you need.
Then climb away.
With one stage of flap it doesn't fare well in a certain grass strip.
1/60
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There are instructors and there are experienced pilots. Being one, does not assure that you are also the other!
In the circuit we had to make it tight and fast due to traffic. On final he attempted (as passenger!!! I was PIC, it wasn't a dual instruction flight) to pull on the flaps while I was decelerating, before the airspeed went into the white arc (96 KIAS). Well before in fact. I stopped him and ensued a brief argument that it was "OK as you're only 5 knots above". Well, no it was not OK on several grounds: 1) I was PIC, not he; 2) it is my aircraft, not his, and I operate my aircraft within published limitations only and 3) he was a bloody fool.
Needless to say, not only does he no longer instruct me, I won't let him at any control position of my aircraft. And should you think that this was some junior instructor, he was the owner of the flying school and an instructor for a good 10+ years when this happened.
As for the flap setting for a short-field in a PA-28, my goof, I believe folks are right, it is two notches not one. I sold my PA-28 6 years ago and no longer have a PA28-140 POH, and my memory is failing me!
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And another...
Another, non-approved short take off technique was similar to others above: begin the take-off roll without flap and at 50-55mph bring in two stages. On the 140 it will bounce straight up as if on afterburner.
With no flap the aircraft accelerates faster but when you clunk in the flap the increase in lift has a dramatic effect. It has also worked on a 181 i used to have a share in.
Not sure I will try with full flap though; I avoided that because of the drag.
With no flap the aircraft accelerates faster but when you clunk in the flap the increase in lift has a dramatic effect. It has also worked on a 181 i used to have a share in.
Not sure I will try with full flap though; I avoided that because of the drag.