Early on in my flying, I got some experience flying an old 150 off of muddy farmer's fields during the "mud season" in Vermont. The trick was to find the "sweet spot" angle of attack that would get the nose wheel out of the mud while not incurring too much aerodynamic drag. By increasing your angle of attack and using flaps, you're "lightening" the plane on the wheels, further reducing rolling resistance, while trading it for more aerodynamic drag. The trick is to find that "sweet spot."

I'm guessing it's different for every type of plane, so it's one of those things you'll probably need to experiment with.

I'll also second the votes for more flap. My feeling with the sportsman is that it likes more flaps on takeoff than the stock wing, so there's a good chance that the Horton will perform better with 20 degrees.

I have found the best short field technique for a tricycle gear'd A/C is to dig out the cell phone and call your TW buddy.



That said, +1 on more flaps. With the STOL cuff installed, the factory manual is a bit out the window. I know that in my Wagon, Vx is now 30 degrees at 53 MPH. Steep and scary, but effective!

motoadve wrote:What about the technique with the Sportsman STOL kit.
10 degrees to start ,and add 20 degrees more at 40 mph.
It goes up in short distance but it is distracting to add flaps in a narrow short , bumby strip

Any other technique you guys use with this STOL kit?

RE: pulling flaps on the run... Its generally considered a more advanced move, but the fact is that is will really only shave a short distance off the roll, so if your not that comfortable, its generally better to just start with all the flaps rather than to monkey with yaking them while in a critical phase.

I typically start with 10, then yank between 30-40 to get her up, then settle in to 20 or 30 till I've cleared the obstacle, then slowly milk them out for a Vy climb out (which is pretty damn slow with WingX and Sportsman.

bigrenna wrote:I have found the best short field technique for a tricycle gear'd A/C is to dig out the cell phone and call your TW buddy.



That said, +1 on more flaps. With the STOL cuff installed, the factory manual is a bit out the window. I know that in my Wagon, Vx is now 30 degrees at 53 MPH. Steep and scary, but effective!

motoadve wrote:What about the technique with the Sportsman STOL kit.
10 degrees to start ,and add 20 degrees more at 40 mph.
It goes up in short distance but it is distracting to add flaps in a narrow short , bumby strip

Any other technique you guys use with this STOL kit?

RE: pulling flaps on the run... Its generally considered a more advanced move, but the fact is that is will really only shave a short distance off the roll, so if your not that comfortable, its generally better to just start with all the flaps rather than to monkey with yaking them while in a critical phase.

I typically start with 10, then yank between 30-40 to get her up, then settle in to 20 or 30 till I've cleared the obstacle, then slowly milk them out for a Vy climb out (which is pretty damn slow with WingX and Sportsman.

Been flying a friend's 172. I can get it off pretty short by popping 30 or 40 flaps, then immediately milking them back down in ground effect to get some speed up. So that is what I do. So I agree with bigrenna...however, I think the utility of such a procedure is much less clear if you are in the world of electric flaps. The manual bar flaps makes this an option, but the ability to choreograph the electric flaps is less clear to me.

And my friend's 172 has a Horton STOL kit installed, so not sure how well the 30 or 40 would work with a stock wing. But again, if you are just trying to get off the ground, try out some different things, not just what you read. Climbing with flaps is a bad bargain, but getting airborne they can be an asset.

bigrenna wrote:
RE: pulling flaps on the run... Its generally considered a more advanced move, but the fact is that is will really only shave a short distance off the roll, so if your not that comfortable, its generally better to just start with all the flaps rather than to monkey with yaking them while in a critical phase.

I typically start with 10, then yank between 30-40 to get her up, then settle in to 20 or 30 till I've cleared the obstacle, then slowly milk them out for a Vy climb out (which is pretty damn slow with WingX and Sportsman.

A Pacer owner posted an excerpt from a 1950's Piper POH on this forum a while back. According to the Piper manual he referenced, pulling flaps on the run (last-second "pop") produced a 20% decrease in takeoff roll.

I'm not sure why it's wrong to monkey with the flaps while in a critical phase. Is there some kind of an issue there?

Sorry double post.

EZFlap wrote:

bigrenna wrote:
RE: pulling flaps on the run... Its generally considered a more advanced move, but the fact is that is will really only shave a short distance off the roll, so if your not that comfortable, its generally better to just start with all the flaps rather than to monkey with yaking them while in a critical phase.

I typically start with 10, then yank between 30-40 to get her up, then settle in to 20 or 30 till I've cleared the obstacle, then slowly milk them out for a Vy climb out (which is pretty damn slow with WingX and Sportsman.

A Pacer owner posted an excerpt from a 1950's Piper POH on this forum a while back. According to the Piper manual he referenced, pulling flaps on the run (last-second "pop") produced a 20% decrease in takeoff roll.

I'm not sure why it's wrong to monkey with the flaps while in a critical phase. Is there some kind of an issue there?

No issue for me. But I have long arms.

My opinion is that 30 or 40 degrees of flap probably works great in the northeast with density altitudes of maybe 2500 feet and 230 hp at light weights, not so good in central America with a density altitude of 6500 feet and 195 or at most 210 hp. I would bet that a stripped down 180H and a 172 xp are very close in empty weight. My point is that configuration recommendations based on one location may not be of value or even safe in another. Few will disagree with the statement that a stock 145 hp 170B is under powered at higher density altitudes, but as an example Cessna performance data for the 1955 170B has the following note "In this area, the use of wing flaps will increase take-off distance. Under these atmospheric conditions, it is recommended that take-off be made with flaps up". Now the rest of the story, the area they are talking about is 4000 ft on a 80 degree day, 6000 on a 40 degree day and 7000 feet on a 20 degree day. Yes, I know we are not talking about a 145 hp 170 but something to think about. A little test flying will go a long way.

Tim

I used the pop full flaps regularly on my tripacer on my idaho trips.... no flaps full power to get rolling and pop full flaps at about 45 MPH and the old tri rock jumped into the air... Same for my M4 but It gets off short anyway but if I really wanted to get airborn short I can pop full flaps and the Maule jumps into the air like you wouldn't believe......

I have found myself on that kind of soft ground many times. What I found works best for my 172 is to set the flaps to match the ailerons(15*?) , pull the yoke full back and apply power. This usually gets the front wheel off the ground quickly and the mains usually come off right around 40 mph indicated. As soon as the mains are off the mud I can feel the plane start to accelerate much faster. I immediately lower the nose and start to bleed the flaps off. Once I hit 80mph I start the climb. Trees, fences and barns can modify the last bit of the program but getting the wheels out of the mud or tall grass quickly seems to work for me. The only time I usually find myself in those conditions is when I have to deliver a replacement tail wheel to one of the local 180 guys. It seems the little wheel in the back is a very weak design.(hehe)
KenW

bat443 wrote: Few will disagree with the statement that a stock 145 hp 170B is under powered at higher density altitudes,
Tim

I agree. The 180 hp upgrade kicks things up a bit though...

Who needs a Citation?

FIRST NO BRAKES AT ANYTIME ! Taxi from your parking spot -while en route run engine up for simple mag check /prop cycle on a roll. Roll into turn for takeoff and apply full power aimed down the runway,lift the nose (like soft field) when airspeed indicator starts to move off peg drop 20 degrees of flap .Airplane should "hop" off ground at foot or 2 roll nose over and get more speed . Keep flaps down until your well above terrain. Works for me .