PA-28 short field take off flap setting

[DarkSoldier]

I fly a few different PA-28s, one is a -140 one is a -150 and the other is a -180. I've checked all three POH but none mention anything about flap settings for short field take offs.

What is the usual practice for short field TO? I've heard flap 25 is most common, but does this differ between the different types, or is it standard for all Warriors/Cherokees?

Thanks

[Lister Noble]

I learned on a PA 28-180,and I think it was first stage of flap for short field take off.
Lister

[hatzflyer]

The safest way of getting a heavy PA 28 out of a short field is on the back of a lorry!

There is a well known tecnique though for short fields. Full power against brakes. No flap, release brakes for max acceleration, about 10 mph below normal lift off speed pull full flap.The plane will jump into the air,at which point you must not pull back! Allow the plane to accellerate whist slowly retracting flaps to first stage, effectively trading sink against accelleration and once speed is sufficient ,establish a posative climb.

As an even shorter take off,(if runway width allows it),start the run in the opposite direction to the take off and turn into wind (180 degrees ) as fast as possible so that you are already doing 15/20 mph as you head into wind and then do as above. This tecnique is especially efective for muddy grass strips but you have to beware of skidding when making the high speed turn.

It may sound dodgey but when carried out by an acomplished pilot who is familiar with the aircraft and is in practice it can shorten the take off of a lightly loaded pa28 by 50%. DON'T TRY IT ON A SHORT STRIP AT MAX UAW FOR THE FIRST TIME!

Try it with someone that knows what they are doing and with plenty of room first.;)

[BR7]

My first posting so please be gentle....

I agree with Lister, 1st stage of flap with brakes on, up to full power and then then brakes off. Pilots operating manual should give you the best pointers, but putting flaps in at the last moment sounds like a no-no to me?!

BR7 :ok: Happy Take-offs

[Brooklands]

DS,

I used to fly a PA28-180, and we used 25 degrees (2 stages) for shortfield takeoffs. Other variants may be different.

Brooklands

[Tigger_Too]

From the POH for a PA-28-181:

The procedure used for a short field takeoff with an obstacle clearance or a soft field takeoff differs slightly from the normal technique. The flaps should be lowered to 25 degrees (second notch). Allow the aircraft to accelerate to 41 to 49 KIAS depending on the aircraft weight and rotate the aircraft to climb attitude. After breaking ground, accelerate to 45 to 54 KIAS, depending on the aircraft weight. Continue to climb while accelerating to the flaps-up rate of climb speed, 76 KIAS if no obstacle is present or 64 KIAS if obstacle clearance is a consideration. Slowly retract the flaps while climbing out.

perfectly straightforward, and frankly you would be unwise to try anything substantially different.

[BR7]

I might be wrong, I usually am, but with a 140 I'm sure it's 1st stage of flap with 65mph as rotate speed. Is the 2nd stage of flap with a 180 due to increase in weight with this model? I think 495m @ Leicester is the shortest runway I've taken off from with pax in all 3 seats. No problems on half tanks although I did make sure all was within weight and balance calcs before taking off from initial departure airfield, so reduction in fuel to get to Leicester can only have helped.

BR7 :)

[Pilot DAR]

Yes, but....

(a repeat of a post I previously made...)

PA28's have a stabilator rather than the conventional stabilizer/elevator combination. In "normal" operations this is a completely benign difference. Where it does show up, however, is in very low speed, nose high operations. Here's what happens: Pilot commands more nose up at low speed, takeoff being the most likely occasion. Where the conventional stab/elev combination would have a greater deflection of the elevator, the camber of the horizontal tail as a single flying surface is increased (as well as a change in effective pitch angle). As such, it's capacity to create more "down" lift before stalling, or experiencing a large drag increase is better. (okay purist aerodynamicists, have at me, I've got experience with the result, not the theory). On the other hand, the stabilator, has only the opportunity to change angle of attack to create more "down" lift. Like any flying surface, it will reach an angle of attack, where the Cl max has been passed, and the increase in drag is no longer proportionate to the increase in (down) lift. Yes, I'm sure that Piper gave this a lot of thought and test all those years ago, and their engineers know more than I do about this, but...

I was the right seat check pilot to a junior pilot in an Arrow PA28R-200 many years ago. He rotated prematurely out of a 1000 meter runway. It was a hot day, but we were quite light, and it was a 200HP version of the aircraft, so power was not a problem. The plane was stuck in ground effect, with the pilot holding the controls 'way back. The stall warning was sounding. The aircraft would not accelerate, or climb away. Landing back might have worked, other than the runway end was approaching, and he (well I suppose "we") had allowed the aircraft to drift off the side, so there was not a runway under us any more. I was shocked at the "poor performance" I was experiencing in this aircraft I thought I knew so well. We were nearing the obstacles. We did not wreck the plane simply because I "locked off" and retracted the gear. The resultant reduction in drag was all that was needed to allow the plane to slowly climb away.

Shocked by what had happened, Later that year, I went to experiment. I flew a PA28-140, which I believed to be in good condition, off a very long frozen lake (runway and width length no longer a concern). Sure enough, I could get the plane very nose high, with lots of aft control, and it would not accelerate or climb out of ground effect. My only option was to land back (fixed gear). I repeated this configuration enough to satisfy myself that this is a configuration to be avoided in PA28's (and probably Cessna 177's as well) So I do! The thick wing has great lift, and resists stalling well. The stabilator tail is not ideally matched in this attribute. Indeed, early Cessna 177’s were AD’d for a change to the stabilator to overcome this characteristic. I’ve never flown a non-AD’d one.

[nick14]

Hatzflyer,

Why would you pull full flap? the last stage is primarily drag and would only hinder your progress.

AFAIK:

I would not suggest that anyone be pulling flaps around on the takeoff roll at rotate speed. Head in a less than ideal viewing position and the possibility of a high speed runway exit are just not desireable.

There is a shortfield technique taught by schools which is the one generally recognised as the correct one.

First of all, make sure with all factors considered, your figures are within those stated for the aerodrome in use.Set flaps as required (10degrees was used at EGBG on the 490m runway) Use all available runway, stop, apply full power against breaks, check T's + P's, release and rotate at correct speed (please refer to the POH for type) I think 55 was normal for the PA28-161.
Climb at Vx (if obstacles are an issue) untill safe to accelerate to Vy and then retract flaps at around 200'-300' feet.

That is all from my PPL days which is a while ago now so I am open to comments

Nick

[hatzflyer]

I didn't say it was the correct tecnique as per the handbook.What I said was it is a well known tecnique that works. I and many other cherokee drivers have used it,but would not recommend it if you don't know what you're doing.In fact nowhere in the last post did I recomend it.I only said it can be done.

I still stand by my opening comment," the safest way to get a PA28 out of a short field is on the back of a lorry" to which I add "especially the lower powered versions!".:}

[nick14]

Fair play,

I agree with your last point, they don't exactly blow you away with their performance :}

Nick

[isi3000]

I learnt in Warriors and Cadets, we used 2 stages of flaps, hold the brakes and up to full power then release the brakes. Then at 200 feet, retract the first stage of flaps and the second at 300 feet.
As for the comment on the full flaps in one go, you can take them out while you still have a positive rate of climb. Ask an instructor to show you :E

[hatzflyer]

Nick,the reason for full flap is that it effectively traps an air pocket under the wing and the sudden application is enough to get the wheels out of the draggy muddy stuff. It works on most low wing mechanical flapped aircraft.
It does mean that you are semi stalled at that point and requires finess to fly accurately in ground effect whilst letting the speed build before attemting to climb. If you let it settle back into the mud then you are in trouble.

[Stampe]

Huge difference in the wing between the early hershey bar wing models and the later tapered wing models.I seem to remember 2nd stage 25 degree is recomended in the comprehensive poh. for the later models.The earlier slab wing models I have come across have had much less comprehensive flight manuals.VBR Stampe

[Johnm]

You would never use full flap on take off in any PA28 unless you were tired of life!

The two wing shapes on early and later PA28 are fundamentally different and I can't speak for the older "Hershey bar" or slab wing variant.

On the later version it's two stages of flap, full power against the brakes and as per Tigger too's quote from POH.

It is possible to get airborne quite swiftly by accelerating to about 45 to 50KIAS and then pulling on 2 stages of flap, whereupon the little beast fairly jumps into the air and flies along in ground effect as you accelerate and climb. I can't vouch for this shortening the take off run over the book recommendation though I've tried it just for fun on a decent length grass runway.

[mde]

Short field take-off PA-28/180
1200 hrs P1 on type based on a 450M grass strip for 10 years—238 take –offs and 237 landings: farmer emigrated and closed the strip. Crosswind limit 20knots mine -POH has a demonstrated limit of 17knots. The test pilot was being conservative in a litigious society i.e the states
First stick to the POH until you have practiced and mastered any other method that takes you outside of the POH recommendations. Practice on a good long runway with no obstructions.
Start with common sense—wind direction, if a wide runway start to one side so as to reduce the cross wind component. If necessary push the A/C back until the tail touches the hedge, runway behind you is like the fuel you left in the bowser. Fuel—consider its weight if necessary always land back reasonably low on fuel for the next take-off sufficient obviously to reach the next refuelling place.
Never have attempted the 180 degree turn but if available use a taxiway at the end of the strip to accelerate and turn onto the runway with maybe 10 knots of speed, much more would put quite a stress upon the undercarriage.
your aim is to accelerate as quickly as possible so 1st stage flap setting, all checks complete, engine up to temperature, we will assume we are taking off from an elevation below 1000AMSL so no leaning required, feet hard on the brakes, handbrake off and check, full power, control wheel hard back- our aim is to effectively lighten the weight of the A/C on the ground so as to accelerate as quickly as possible, ensure feet or OFF the brakes, play the control wheel so as to maintain the nose wheel about an inch off the ground much more and you may get into aerodynamic drag (outside my scope) at around 50/55 knots the a/c should fly away—now to the controversial bit if the runway end is approaching fast then by all means pull on full flap (Prior practice please) the a/c will leap some 2 metres into the air but climb and airspeed increase is considerably degraded but will get you over the ditch / low hedge and allow you to consider at best not the repair bill but should I base myself and the Cherokee 180 somewhere else
I will repeat practice where you have plenty of runway and keep in practice
As a aside from the above pick an abort point where if the ASI is not alive STOP

[hatzflyer]

John M ,"You would never use full flaps unless you were tired of life".
WRONG!!!
As substanciated above,in extreme conditions this tecnique could save your plane if not your life.
Would you dissagree with the above posters experience?
My own is 6thousand hours of strip flying with 178 types flown over 30+ years.
perhaps you have more experience than us?

[Local Variation]

Have seen it done at first hand only once.

4 x shall we say, well built adults on a short grass strip. The 2 in the front were both Instructors. No flap set, brakes on, full power. Got over half way bouncing down the track and in came 2 stages of flap and up we went like a scolded cat.

Generally speaking I set as recommended, 2 stages of flap for both the 140 and the 180 models on short strips. I've seen others get up equally efficiently on 1 stage also................but never 3.

[homeguard]

The only official statement that I have seen that suggests commencing the TO run prior to deploying flaps is in a 1950s PA22 flight manual.

Owing to this commonly held believe, I did, some years ago, make actual flight comparisons. On one occasion we compared the C172 POH recommendation of presetting flap 10 degrees for soft ground. Immediately after the POH technique we used the alternative technique deploying flap at the point we scheduled to become airborne. On another occasion we did the same using a PA28. It was important of course that we did the TO's one after another to ensure the wind and air density conditions remained the same. The changes to fuel onboard following the first TO we considered to be minor.

Conclusion - no difference at all!

It was concluded by everyone that the additional distraction of deploying flap at the point of becoming airborne; in the case of the C172 having to monitor the electric flap setting and in the case of the PA28 the requirement to stretch down to the cabin floor for the flap handle was poor airmanship.

[Pace]

There is a well known tecnique though for short fields. Full power against brakes. No flap, release brakes for max acceleration, about 10 mph below normal lift off speed pull full flap.

There is another technique as the aircraft accelerates to VR ask your passengers to push upwards and rise off their seats filling the cabin with helium balloons also helps :)

Seriously I have used the clean run technique especially in PA28 S with manual rather than electric flap.

It is pointless and infact dangerous to pull on full flap. The most lift comes with first stage so if you are going to use that technique never use more than first stage or the flap stated in the short field takeoff in the POH.

Full flap is mainly drag and a massive amount of drag and the last thing you want when close to the ground, at slow speed trying to coax a climb.

Read Pilots Dars excellent Post and his warning as until you experience something like that you do not realise how scary such a situation can be.

Pace

[BeechNut]

There is a well known tecnique though for short fields. Full power against brakes. No flap, release brakes for max acceleration, about 10 mph below normal lift off speed pull full flap.The plane will jump into the air,at which point you must not pull back! Allow the plane to accellerate whist slowly retracting flaps to first stage, effectively trading sink against accelleration and once speed is sufficient ,establish a posative climb.

Negative on this. With about 300 hours in PA28s (mostly 140s, my own and rented), I can assure you that this is a technique that will bite you really bad.

First of all the PA28 is not exactly overpowered, especially the -140. By pulling full flap at 10 mph below lift off, you are putting yourself in a low-speed, high drag configuration, less aileron authority, and your ability to clear a 50 ft obstacle, or any other obstacle will be severely impaired as you will require longer in ground effect to accelerate out of it and start climbing. As I recall the manual allowed for 1-notch of flaps on takeoff in short-field situations. And yes, you can stall out the stabilator on a PA28. It's quite a suprise to be applying downforce to the stabilator (i.e. pulling back on the stick as in flare) and have the nose come down rather brutally.

There is a little thing called the "takeoff performance chart" in every POH. It has calculations made by test pilots and engineers. They have conducted tests that determine what configuration and technique will require the shortest takeoff distance to clear obstacles. If you deviate from the procedure you become a test pilot, and you will no longer meet the calculated takeoff distance requirement. Any deviation you use will be either less safe, or will require more distance than in the POH.

There is a proper way to execute a short-field takeoff in a PA28 or any other aircraft for that matter: know your gross weight, calculate your density altitude, note the type of runway surface and approximate height of obstacles at the departure end of the runway, have a good estimate of wind direction and strength, then sit down with the POH and determine your takeoff distance. If the distance available is shorter than what the book says you need, the only safe alternative is to offload weight until you can meet the book performance with a safe margin, or as you said earlier take it out on a lorry. A big problem with many aircraft (the C150 can get into this mess too) is that it is very easy to land in a field you can longer depart from. If you determine it can be safely done from the POH, then follow the POH's procedure to the letter, for short-field takeoffs if one is published.

In my younger and foolish days with my PA28 I did try to pull in my 1 notch of flaps near takeoff speed, at max. gross, to "leap" into the air as has often been suggested and it nearly killed me. First of all it lengthened our ground run as I was distracted from actually flying the aircraft, and that in turn, ensured that I only barely cleared the obstacles at the end of the 2500 ft runway. I was shocked to learn, after calculating density altitude after the fact, just how little margin of error I had (2200 ft required, 2500 ft available). I swear those treetops tickled my my ar$e on the way up. I never want to be in that situation again.

My current ride, a Beech Sundowner 180, has a 65 knot rotate speed and the manual does not call for flaps on a short-field departure and does not have a specific short field procedure. It has laminar wings with a high wing loading and also a stabilator. Earlier versions allowed 1-notch takeoffs but there were accidents as the plane had trouble flying out of ground effect. So later versions like mine had this removed from the POH. I tried, on a long, unobstructed runway various techniques for getting it off the ground at less than 65 knots.

None of them I considered safe. The safest practice is to land in a field that you have determined beforehand, you will be able get out of.

Fly smart, fly safe.

Beech

[hatzflyer]

30 years...it aint bit me yet:rolleyes:

[jollyrog]

You can learn so many useful things from Pprune.

I'm just about at 200 hours on my PPL, which according to several informed websites makes me "invincible":cool:. I also fly a Warrior.

I'll be trying out all these good ideas at the weekend on a 400m strip that I plan to fly to.

Thanks for the excellent advice.:ok:

[Pilot DAR]

In 30 plus years of flying, I havn't been bit yet either. Mostly luck, I'm certain. Early on (around 200 hours) I had the excuse of in experience to justify some of my foolish behaviour. Long ago, I lost that excuse - I now know better. I get to be inexperienced in helicopters now...

There are many things which I can still do very well in airplanes, a number of them not strictly in accordance with what the flight manual says. Some of these things I occasionally allude to here, many of them I never would. The fact that I am able to safely handle an aircraft during manuevering "outside the norm", does not mean that I'd write it into cyberspace! Odd flap techniques are know to me for water flying. I would happily demonstrate them, but will not describe them here. I don't want my conscience dealing with someone wrecking a plane because they tries something I wrote here, without the benefit of qualified, prepared supervision.

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.

New pilots are reminded that just because you read that people do things in planes, don't assume you can get away with it too! You start your flying career with a full bag of luck, and an empty bag of experience. The trick is to use your judgement to fill the experience bag, before you empty the bag of luck!

[hatzflyer]

Pilot Dar, a very good post. I agree with everything you say.
The point of my previous ( Tongue in cheek, < I did say the safest way to get a heavy PA28 out of a short field is on the back of a truck>) post is to get poeple used to thinking outside of the box and learn extra skills such as those that you have developed over the years.
I made a point of advising people not to try it on their own,but untill anyone learns these sort of things they will not develop their airmanship.
It grieves me though when some poeple with no experience come on here and shout down others.
Several people have posted to the effect that what I have said cannot/shouldnot be done despite evidence from others saying they use this tecnique. Are we then liars?
However perhaps I would have been better saying that the tecnique is really more of a softfield tecnique than shortfield.

I once had the dubious pleasure of sitting next to a sanctimonious pilot that did " everything by the book" and was a legend in his own mind.Having got the weather briefing, done a c of a for the preflight and reread the checklist 4 times we started the take off. He announced that in accordance with the POH we would start the take off with full aieleron deflection as there was a brisk crosswind which from his weather brief was to be from the left. As we started to roll I nudged his elbow and pointed to the windsock which clearly showed a strong wind from the right. This went unnoticed and as the wing slowly lifted and we started to ground loop I took control. When we got to approx 300ft I gave him the controls back and he said those famous words " well I don't know what happened there, I did everything by the book."

That was over 20 yrs ago, the same pilot now has about 160 hrs in one type but is never backwoods at coming forward with advise for others as he still thinks of himself as being a superior pilot because " he always does everything by the book". :ugh:

[Pace]

Several people have posted to the effect that what I have said cannot/shouldnot be done despite evidence from others saying they use this tecnique. Are we then liars?
However perhaps I would have been better saying that the tecnique is really more of a softfield tecnique than shortfield.

Hatzflyer

I have used the technique of running clean and then pulling in the first stage of flap many times.

What I question is the technique of yanking in full flap.

As you know the most lift comes in early stages of flap the most Drag and least lift comes with subsequent stages and especially full flap in most cases.

Whether the benefit of a tiny bit more lift compared to the negative of a massive amount of drag and the perils that carries is worth it?

Yes there is a danger that some inexperienced pilot will read what he sees here and try it for himself.

Can you explain the science or thinking behind your technique of full flap?

Pace ATP 4000 hrs multi and jet rated

[Pilot DAR]

Hatzflyer,

I completely agree. "The book" is the commonly agreed, best compromize between performance and safety for the average pilot skill. Once an aircarft is experienced in service, "tribal knowledge" will be developed by it's most experienced and adventurous operators. That knowledge will most certainly be techniques and capabilities beyond what the flight manual presents.

Prior to information whizzing around hyperspace, the only source of tribal knowledge, was it be in the tribe (if they'd let you in). Now we have "who knows?", reading all of this, and becoming very well informed, but no better skilled - it worries me.

Last year I demonstrated some advanced techinques in my STOL Cessna 150 to a 200 hour CPL ME IFR PPRuNer who came to visit. I was amazed at how much this pilot had not been taught. This pilot was apparently stunned by how much there was now to learn, that had never been imagined!

My task earlier this month was to vet and draft flight manual wording for a new variant of a well known new twin. With some of the wording in place, we were flight testing to validate the procedures. After flight testing, we changed the document even more - so a new pilot would not hurt themselves, if they did it the way the book says. During the testing, (and by prior planning) it became absolutely unavoidable to have to fly with a L/R fuel imbalance three times the maximum permitted by the book. It worked fine, but we're going to leave the flight manual as is...

The minute the super pilot get's it wrong, he'll be looking for someone to blame. I'm not going to set my self up for that!

Pilot DAR

[hatzflyer]

I already have to a degree but to repeat and add a none too technical reason its because it is really a soft field tecnique. By pulling full flap, due to the proximity to the ground,the flaps act effectively as an air dam and provide a cushion of trapped air which pops the wheels out of the mud, there by relieving the extra drag on the wheels and allowing the plane to accellerate to a speed at which flight then becomes possible (which it would not otherwise do.) albeit in a semi stalled condition. This is where the skill comes in as eluded to in my previous post ref. raising flaps slowly to trade drag for speed and then climb(strictly in that order!).
It is of no use on a long tarmac runway obviously,where as you correctly say they would increase drag. Hence my reference to muddy fields and cautions about skidding. Perhaps I did not make this clear in my previos post for which I apologise!
I have also used this tecnique in a Beach Sundowner.
This phenomonon was exploited by some aircraft designers that put belly flaps on their aircraft when plain or split flaps were the norm but this seems to have gone out of fashion with the more widespred use of better (eg. fowler type) flaps. :)

Edited..Obviously this tecnique will not work with high wing or electric flaps.

[BeechNut]

Just keep in mind that there are two things to worry about: getting off the ground, and clearing obstacles. A PA28, especially the -140, is no Ferrari of the air. Your idea of full flap may work if there are no obstacles, but keep in mind that the time needed to clean up the aircraft to climb away may very well lengthen your distance to clear the theoretical 50' obstacle.

Nothing beats knowing your aircraft, and I have operated outside "the book" on numerous occasions, in a safe setting, to learn just what was possible in a pinch. I know how my aircraft operates in just about every configuration including in a spin (it is cleared for it, my Sundowner is one of the rare ones with the aerobatic kit installed). The field where I operate from is 5000 ft of asphalt but I also fly into a buddy's farm that is 3000 ft grass with a mountain at one end, and my home base is infested with deer, so being able to haul it off the ground early may be useful some day (I have manual flaps). But I don't think it should be routine unless you are very, very practiced at it. I do know for a fact with my Sundowner, without flap, any attempt to pull it into the air below 65 knots is futile and quite possibly dangerous, and it will definitely only increase your takeoff distance.

[Pace]

Hatzflyer

be careful that this idea of full flap is not an illusion.

Its not my intention to point score here as i can see an arguemnt for putting in first stage of flap to slightly shorten a takeoff roll.

First stage of flap may be advised in the POH for a short field takeoff technique.

Running clean till near rotation makes sense as you are using the published short field takeoff but keeping the aircraft clean until near rotation and then adding the lift with minimal flap drag this has to allow the aircraft to accelerate slightly quicker and at rotation you get the lift from first stage of flap.

Here is where I have a problem! in both cases first stage or full flap you are running to near rotation clean on soft or hard ground so there can be NO benefit until the point that the flap is applied.

In most cases the small extra lift generated by taking full flap is negated by the massive increase in drag compared to the large lift and small drag of first stage.

BUT! the illusion will be different! applying full flap will have two effects giving an ILLUSION of elevator type lift.

Firstly there will be a huge amount of drag. That will give an instant braking effect and a momentary deceleration. Couple that with all the flap lift and that will give an ILLUSION of springing into the air which will not be as prominent as with first stage.

Once in the air you are now saddled with huge drag, a reluctance to accelerate or climb and still in ground effect.

What I feel you are getting is braking and levitating kidding the mind into an illusion.
I bet if you put this to scrutiny you would not be getting what you think you are getting as it makes no scientific sense that I can think of.

As stated I am not trying to point score on you but to convince myself of your arguement and NO i am not known as a by the book pilot either :)

Pace

[hatzflyer]

My flights out of less than 300yds of wet grass are no illusion I can assure you.
I am not in the habit of telling lies,and quite frankly am bored of poeple telling me I can't do something that I HAVE done many many times.Q.E.D.

[Pace]

My flights out of less than 300yds of wet grass are no illusion I can assure you.
I am not in the habit of telling lies,and quite frankly am bored of poeple telling me I can't do something that I HAVE done many many times.Q.E.D.

Hatzflyer

There is no need to go defensive I am sure you are a very capable competant pilot and do go out of your 300 metre wet grass strip but what has that got to do with discussing the merits and validity of your technique?
I am trying to be convinced of it not to shoot it down. There is a difference

Pace

[Final 3 Greens]

Hatzflyer

I think the question is have you done the same thing with the first and second stages and what is the difference to performance.

As to 300 yards of wet grass in a PA28, that's a risk to far for me, but don't take it as criticism, just my own feeling.

I've done 360 metres in a C172 and was at the edge of my comfort envelope.

[tigermagicjohn]

Pulling full flap during roll, is CRAZY - as last stage is mainly DRAG - and you don't want that.

Here technic used on a snowy runway in Norway - and did not need much rwy to get of the ground.

2 stages of flaps, brakes on - full power, stick fully pulled back - let go of breaks, increase in speed, as soon as lifts of forward level stick pressure to build up speed and climb.
You hear stall warner as you leave the ground, however did this in both C-172 and PA 28, same technic, was thought to me by norwegian SAS pilot mostly flying F50 on the west coast of Norway, snowy jungle weather.

You will leave ground at around 35 kts speed, important to release back pressure as you take off!

[Pilot DAR]

You will leave ground at around 35 kts speed, important to release back pressure as you take off!

...Is in my opionin crazy! I'm not saying it cannot be done... but see my earlier post...

There are some runways that some aircraft don't belong in. If that technique is required, the owner should be shopping for a STOL kit!

Non-approved use of the flaps might have some value in soft surface conditions, where space is not a problem, but if it's a short runway, I'd be doing what the book says, for fear of having to explain myself to the insurance company later!

There's a fine line between "let me help you learn" and "watch this". I no longer go on the "watch this" side..

Pilot DAR

[tigermagicjohn]

This is short soft field take of which I thought by a highly competent commercial pilot in Norway.
This is I believe what is in the "Book" for short soft field take offs, I just stated the fact that I was surprised to notice that the airplane left the ground at around 35kts.

I do think if you do a little more research you will discover that this probably the best technic to get of the ground in shortest possible time on a soft airfield.

As I also fly in the UK, I did ask some of my instructors regarding this, and they confirmed this to be the correct technic for this specific condition.

Why?

We was making the take off in 7 -8 cm of snow, yes we had a long runway, however the snow slows you down during your take of run, just as soft wet grass ground will. So you want to get the wheels of as soon as possible and then build up speed for further climb.
Most have heard the phrase to put back pressure before reaching rotating speed, at 1 stage flap you can rotate quite safely at around 50 kts, without flaps I would use 60 kts.
The 35kts I mentioned was on the C-172, what the PA 28 speed was I did not take note of.
The C-172 stall speed full flap is 33kts, no flap 44kts !
(on the PA 28 161, its 44kts and 50 kts)

If you are on a soft ground, you do not want the friction to slow you down to extend your take off run more then max required. Full back pressure on the stick, will make the aircraft fly itself just of the ground when sufficient speed V has been reached - and then without the friction of the soft runway to slow you any further you can build to safe climb speed, either Vx or Vy, whatever is required.

And with a bit of research you will discover this is not a magic secret crazy that the aircraft flyes itself of the ground at relative low speed - let me note it will also almost wind still conditions.
What was my big surprise was how low the speed was before it left the ground, and secondly how easy it was to do this kind of take off.
However you still need some clearing ahead to build up speed before you can start the climb, however you will build up this speed faster once you are airborne/off the ground.

Maybe it was 35 - 36 - 37 or 38 kts, at the moment it was not my major concern to get the speed readout exact, but I was surprised how low the speed was to get OFF the ground!

[mde]

Come on folks, some of us have been around a fair amount of time a few thousand hours in my case(no instructing and all on light aircraft) we dont advocate the use of full flap rotation on a PA-28 as a norm but when the sh*t hits the fan and you need to get over that ditch at Fenland for what ever reason its nice to know what happens when you select whatever method, it will work. No one in their right mind would expect the aircraft in this configuration to meet the 50 ft requirement but it would be better than being in the ditch. The only reason for full flap/two notches of flap is because for whatever, you have got it wrong. Experience tells you what can be done but only if you try it and practice. Most do not spin an aeroplane but its nice to know how to get out of one(showing my age)

Secondly, since I am in the mood, those of us with a reasonable number of hours under our belt must remember that there are those at the lower end of the scale who expect us to quote accurate facts

Not wishing to pick on anyone in particular but since it the post prior to this
Quote C-172 stalls at 33knots total rubbish without the rest of the data
All aircraft stalls depend on a number of facts such as obviously weight, power,angle of bank, the rigging of the aeroplane to name but a few. By the above criteria each aeroplane is an idividual and stalls at whatever that ASI indicated. Try stalling at Fenland then try at Reno in the same aeroplane

So folks facts only please my son may read this

[tigermagicjohn]

Yes these are the FACTS of reality!
These were the specific instructions given by a Captain of SAS, Scandinavien Airlines, flying F50 - on inland routes of Norway, in addition he is CPL instructor and boss of the local flying school, probably has around 20.000 hours, flying nationally in Norway - think he should know what he is speaking about?

On the other hand, stall speed are only given as guidance, of course we ALL should know the aircraft stall at a specific angle of attack, and not at specific speed!

This is how short soft field take of is thought at this flying school in Norway!

[Pilot DAR]

You hear stall warner as you leave the ground, however did this in both C-172 and PA 28, same technic, was thought to me by norwegian SAS pilot mostly flying F50 on the west coast of Norway, snowy jungle weather.

You will leave ground at around 35 kts speed, important to release back pressure as you take off!

For the purpose of this discussion, there are mighty important differences between a C172, and a PA28. I assert that a 172 can be flown this way with adequate safety - a PA28 much less so. The reason you don't reselect flaps in a 172 in motion is that other than the very oldest ones, they are electric, and move too slowly to capitalize on this affect. A manual flap Cessna on floats does have some operational benefits from changed flap settings while in motion.

Trying to fly a PA28 at 35 kts close to the ground is a very bad idea.

Though it was not initially relevent, this video may now offer some insight to the discussion. It is a soft field (deep snow) technique I sometimes use, when runway length is not a factor. If I work at it, being off the ground at 30 kts can be safely done. This aircraft is STOL kitted:

C150 40 Flap Takeoff video by PilotDAR - Photobucket (http://s381.photobucket.com/albums/oo252/PilotDAR/?action=view&current=C15040FlapTakeoff.flv)

Pilot DAR

[tigermagicjohn]

As I did mention, the approx. 35kts scenario was in the C-172, the PA 28 will be at little higher speed, however main principle, 2 stages flaps, Brakes on, Full power, 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.

The scenario of setting full flaps from clean configuration during the roll does not make sense, the first thing one should do during a go around is to reduce the full flap to 2.nd stage flap, because 40 degree flaps is a drag flap - and will also pitch nose down, CG and CP will be moved - it basic like putting air brakes on. I think it is more an illusion that this improves the take off distance compaired to the POH guideline.

High flap setting also decreases the angle of attack for the stall, so you will stall at a smaller angle then in clean configuration, so the likelyhood of stall is also increased with this way of take off.
You are approaching rotation speed, slam 40 degrees of flaps, speed will decrease - aircraft will balloon up, and might reach critical angle of attack, which will be much lower with 40 degrees of flaps, you might stall in the baloon setting full flaps.

This thought that some people have is an illusion of the mind set, like the glide, when you on the best glide speed, it seems tempting to raise the nose, because you think you might glide longer, however the manufactur has tested the aircraft and set the speed for best glide, still some people might illude themselves that this is wrong too.

Any common sense - from knowing how full flaps work on approach, you put the large stage of flaps and the aircraft drops like a stone trough the air, how can that effect possibly be any good during a take off? It's fairly logical, and you should have learnt this during the studies of Principle of Flight ! ?:D

[Pilot DAR]

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.

Yes, but in a PA28, fastested into trouble as well. New pilots: Do not attempt this!

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?

[homeguard]

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.

[much2much]

r mr tigger are you a winnee the pooh fan or do you have a triumph or AA5 :uhoh: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

[Pace]

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.

Homeguard

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

[englishal]

Crikey! How many different opinions by the chest banging thousands-of-hours brigade! here are my observations for what they are worth......

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.
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 ;)

[bjornhall]

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! :)

[Keef]

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.

[Cows getting bigger]

Keef, that is more or less what I do. interestingly, the POH for the slab wing Arrow doesn't have that little CAA note.:O

[Pull what]

The safest way of getting a heavy PA 28 out of a short field is on the back of a lorry!The best piece of advice I have ever seen on this forum!



Speed is your friend drag is your enemy.
But here is another
Both can be your enemy as can ignorance

[rug-rats]

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:)

[Pull what]

I have only ever flown about 5 1/2 hours PUT so what do I knowhttp://static.pprune.org/images/smilies/smile.gif

Probably more than some of the other self appointed experts who will be not so honest with their lack of experience!

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.

[englishal]

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.

[Pilot DAR]

There are instructors and there are experienced pilots. Being one, does not assure that you are also the other!

[Craigeedee]

I fly PA28-161, and have been told for short field take off to use the 2nd stage.

[notfarg]

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

[Pilot DAR]

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.

[Tigger_Too]

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


Pardon?:confused:

[OneIn60rule]

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

[BeechNut]

There are instructors and there are experienced pilots. Being one, does not assure that you are also the other!

Too true. Once I took an instructor to another airport in my Beech one day; he needed to go recover one of the school's aircraft that got stranded due to weather (the pilot returned home via surface transport). I was looking for an excuse to fly so I flew him to the field about 35 minutes flying time away.

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!

Beech

[Gbarral]

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.

[PPRuNe Pop]

Frankly, I am appalled by the apparent total disregard for good airmanship and the lack of interest in the operating manual.

The final stage of flap is NOT for ANY type of take-off - not one! It is there for the final stage of landing only. Playing silly buggers with it for a take-off is iffy at best (soft ground or mud) and courting trouble at worst. Not for nothing do they call the P-28 a brick built s-house!

The assumed fact that someone has been practising this technique without mishap does NOT mean it cannot go wrong. Just accept the fact that it can and will.

In all my years of flying I have never heard of anything so stupid.

NEVER try something an aircraft was not designed to do - the TP did it first and if he didn't write it up there is a reason.

[englishal]

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.

Actually what you'll probably find is that the white arc refers to "Approach Flap" or "Landing Flap" or something and that the first stage can be put in above the white arc. The POH will list the speeds when flap can be put in. I know this is true of many aircraft.....

[Pilot DAR]

One of the things which I learned about life, and aviation in particular, is that generally, absolute statements are not helpful. Generalisations are better.

Throughout this thread, I have been trying to generally say that pilots, particularly those flying PA 28's, are opening themselves up for a flight of unhappiness if they perform takeoffs with greater than the specified flap setting, or at rotation speeds less than those recommended in the flight manual. As I have said, I've been there, and it was not good.

No one here should pretend that they don't know what a proper "normal" takeoff technique would be for the aircraft type they fly. Pilots should definately avoid techniques whic are outside "normal", without training or mentoring. As I have said here, that training or mentoring is not just reading something written here by a pilot of unconfirmed skill and experience. Two reasons for that, you have no idea if that pilot knows what he is talking about, and if he does, can you glean what you need to know from reading only? In the case of unusual configuration takeoffs, most pilots could not. Hands on training and practice would be vital for safety.

So don't go being a test pilot, unless that's what you are employed to do.

That said, a remark like:

The final stage of flap is NOT for ANY type of take-off - not one! It is there for the final stage of landing only. Playing silly buggers with it for a take-off is iffy at best (soft ground or mud) and courting trouble at worst.

perhaps goes further than it needs to in denouncing approved procedures.

I made a remark here about the temporary application of full flaps (40 degrees in a Cessna 180/185) during a float takeoff. I shall presume that the author of the quoted statement disagrees with this technique. I was trained in this technique on the water, where lateral confinement makes the heading change of rolling up onto one float undesireable. I have said that the distraction of the application of flaps during a takeoff run is undesireable for new pilots, and still recommend the roll out technique. That said, the use of full flaps during takeoff is a factory recommended procedure; I quote page 16/17:

"During tests at altitudes up to 8,000 feet pressure altitude, full flap application in combination with a quick jerk aft on the wheel was more effective than employing the one float technique."

This is quoted from the "Notes on Flying Technique for Cessna 180 Airplane Equipped With EDO Model 289 Amphibious Seaplane Floats", which is an EDO publication, available from Kenmore Air EDO Floats L.L.C.

I'm sure that it would be apparent to readers here that this technique is best learned during proper training, rather than casual self experimentation. Did you ever wonder why the Cessna 180/185 aircraft never had electric flaps, where all of the other Cessna models did? Cessna did seek the opinions of their operator clients, particularly the bush operators. Electric flaps just do not move up and down fast enough!

Oh, and by the way, EDO floats are also approved on some PA 28's. I don't have the equivilent EDO publication for those aircraft.

I hope this brings into context some aspects of the discussion, while still convincing the PA 28 landplane pilots out there to fly it the way the book says, and being wary of getting "stuck" in ground effect.

Pilot DAR

[PPRuNe Pop]

You put forward some points which deserve attention but IMHO they still do not justify the technique described on this particular aircraft.

I have flown over 100 different types in all kinds of situations, including the PA 28, and I would never employ full flap during take off.

It is inherently dangerous and can easily lead to grief.

[Pilot DAR]

In the context of a PA 28, I completely agree. A full flap takeoff in a wheelplane PA 28 is completly un-necessary, and particularly prone to being dangerous. If anyone considered it to be necessary, they should be waiting for conditions to change greatly, or trucking out the plane, as previously mentioned.

Other aircraft types are due their individual consideration, but generally would employ only partial (if any) flap for takeoff....

Pilot DAR