sNo problem, sNow problem at all

[piperboy84]

For those that are interested I tried some STOL in the powder snow today with different configurations, see vid link.

Snow STOL - YouTube

See if anybody notices where I arsed up the TO and why?

[Fuji Abound]

I think with that much runway and that aircraft all worries of not getting airborne are totally irrelevant.

It looks a lot of fun.

[piperboy84]

Where did you obtain your performance figures for contaminated runways before attempting this ?

I didn,t

From the written statements at the beginning of your video it seems you were just guessing and trying various aircraft configurations without reference to the AFM

Absolutely Correct, I was just trying different things, the AFM is a guide only (usually a best case scenario for a new plane with a new engine/prop and with a hot shot factory test pilot) and can't give exact real world figures for distances due to individual aircraft of the exact same model having differences in engine and prop condition, pilot technique and many other factors. the numbers at the beginning of the vid came from my nephew pacing off the wheel marks in the snow after each TO and Landing.

To me you arsed up the take-off at the point were you attempted the whole exercise.

Perhaps, But i now know what the real landing distance are when both the plane and myself are pushed to the limits of our respective current capabilities which for the type and location of flying i do is important to me, for example a lot of my flying is between the east to west coast of Scotland which is mostly hills and mountains with sheep farms where the upper areas are steep and impossible to land on without duffing up the plane or myself the lower areas around the farm houses are small non arable (usually grass) pastures and paddocks and rarely exceed 400 to 500 feet in length with drystone dykes at each end. I now have a better gauge of where I can and can not get into in an emergency which frames my options a little tighter and perhaps makes me a safer pilot for my passengers and myself, and that at the end of the day is the name of the game.

[The Original GF]

You can sit in the clubhouse moaning about it, or you can get out amongst it, and learn something!

OGF

[mary meagher]

Loverly conditions, a bit of snow on the runway, but you are flying a taildragger, and THAT makes all the dif.

Having said which, a 152 did just fine for me in Oklahoma, but the runway, covered in light snow recently fallen, was immense. I did get stuck on the taxiway, however.

When landing a glider in tall grass or crop, one touches down at absolutely minimum speed on the top of the crop, everything then settles down nicely, and the world turns green. Same for landing in snow. Taking off, you did the right thing if you walked the runway first to check for drifts!

[Jonty]

Looks like you had a lot of fun!

I reckon you over rotated on the take off. Probably completely wrong though, as I have zero experience of this type of flying. (something Im looking to change!)

[xrayalpha]

Glad to see you were having some fun!
Looks like you only had a couple of inches of snow, which I have flown off quite a few times.
There are four-plus inches here and it has drifted into the hollows, so lovely day but no flying.
With a pusher prop, I turn the engine off as I go over the fence to stop snow being kicked up into the prop - it can fair scour the tips and edges!

[piperboy84]

Looks like you only had a couple of inches of snow

yes it was light, but what struck me is the TO numbers, i have never achieved them on a normal grass TO, granted I was trying my hardest on the snow but wondered if its possible that a very thin covering of powder on top of hard frosted grass actually is LESS friction and allowed me to get the numbers i did

[M-ONGO]

Congratulations on becoming a test pilot!

[piperboy84]

Congratulations on becoming a test pilot!

:suspect: Hardly, just a VFR lowtime duffer finding his feet and pushing the boat out a bit further

[Richard Westnot]

Nice Flying! :ok:

My two small observations were :-

a/ @0.30 - the aircraft pitched down. (possibly incorrect trim set??)
I think that I would have allowed more straight and level
ground effect after t/o, than an immediate climb out with
nil obstructions.

b/ @0.46 - a dog wandering around, off a lead close to the runway.
(presumably, part of your party??)

[mad_jock]

In theory commercially we can accept up to 10cm of dry snow.

But when you look into it the friction coeffcient can vary between 0.1 and all the way up to 1.40.

Given a good length of runway your main issues aren't what you would expect. The biggest danger is xwinds when you are on the ground and getting blown off the side.

So I am not suprised your landing distances are shorter than grass.

But I suspect the expert on this is as usual Pilot DAR

[piperboy84]

RW
a/ @0.30 - the aircraft pitched down. (possibly incorrect trim set??)
I think that I would have allowed more straight and level
ground effect after t/o, than an immediate climb out with
nil obstructions

You are right, i think there were 2 reasons for the dip, at just prior to lift off i pulled the flaps from 24 deg (take off position) to 40deg(landing position) as recommended by other more experienced maule pilots to break ground, however I think I returned it back to 24 degrees to early causing the dip and prior to building a bit more speed and should have kept it in ground effect longer.

[Richard Westnot]

PB84

I am not sure what the Maule techniques are, as I have never flown one, but pulling 40 degrees of landing flap immediately during rotation just doesn't sound right!
(I may be wrong, off course!)

The only time that I have played around with flaps during the t/o roll, is commencing with 0 degrees (no drag) and then pulling 15 degrees (t/o setting) just prior to rotation, to lift her off, BUT, then holding her in ground effect to build the speed
up, prior to climb out.

As Mad Jock says - I would be interested to learn what Pilot DAR says.....

[Skylark58]

I notice the dog was not wearing a hi-viz jacket....

Good for you. Get out there and enjoy yourself. It beats sitting in front of a computer sending a lot of :=:=:=

[piperboy84]

I certainly don't discount the importance of the AFM however I have had instruction by 2 extremely experienced Maule pilots that highlighted to me why certain practices are and are not in the AFM.

The two individuals are Ray Maule ie. "Mr Maule" the guy that builds the planes and another guy in Montana who does pipeline patrol , wildlife monitoring and missing people search's in the Glacier National park with his 2 Maules which he has thousands of hours on.

When flying with Ray he demonstrated a short field TO without bumping the flaps , a few months later I was flying with the guy in Montana who did bump the flaps . I said that Mr Maule did not do this during the flight demo , "Mr Montana" explained why Mr. Maule who builds , sells, trains on and holds the type certificate for the Maule does not do so. Specifically, if he taught students or published in the AFM that you get better TO performance from bumping the flaps (which you no doubt do) but this method involves removing your hand of the throttle, which is a danger in itself, and leaning down to the flap handle which restricts your forward visibility, if someone got hurt or killed while doing this the liability is not worth it for Maule, however if Mr Montana whose home field is 4000ft up in the mountains with his 160hp FP and with a hellacious density altitude he is more concerned with the 50ft oak at the end of a short strip than he is with lawyers.
So it's a double edged sword, you get better performance which in itself is safer, but it's not in the AFM for what i can only assume is liability reasons.

I have enclosed a link from the factory website for the AFM for my aircraft, if anybody can find ANY take off performance data whatsoever I would appreciate them pointing me to it.

http://www.mauleairinc.com/pdf/flightmanuals/mx_7_180a.pdf


Some advice, take it or leave it your choice, although from some of your comments you will probably ignore it.

I never ignore advice, however I do evaluate it,, Fly Safe

[Jonty]

PB,

It really isn't worth replying to these people.

You have done exactly the right thing in taking advice from people who actually fly these things. Don't start taking advice from randoms off the internet. Except mine of course :)

Enjoy the flying, it looks like you had a lot of fun!

[dont overfil]

I'm sure PB knows how to write a risk assessment. He will also know how useful it can be for wiping ones arse should one **** oneself.

Good one PB.:ok:

D.O.

[Echo Romeo]

What I find most impressive is that this took place on the March 13th :D:)

[stickandrudderman]

I suspect that post #1.5 is missing and so subsequent posts don't look right. I presume the missing post was some boring old fart who doesn't know anything.........I'd better stop now.

[Big Pistons Forever]

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.

[Ultralights]

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.

[India Four Two]

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 :ok:

"Contaminated runway settings" in a Maule AFM? :eek: 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 (http://www.tc.gc.ca/eng/civilaviation/publications/tp185-2-00-182-2749.htm)

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.

[Flyingmac]

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.:rolleyes:


Watch the flaps. http://www.youtube.com/watch?v=bPSElw8qEsI

[Richard Westnot]

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.

[piperboy84]

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.

[Richard Westnot]

Piperboy 84

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

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. :ok:

[Pace]

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

[mm_flynn]

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.

[irish seaplane]

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

[dont overfil]

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.

[Pace]

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 :ok: