Shortfield Takeoff Technique

[N419A]

How do you know when your on a short field?

When you pace it for the third time and its still the same length....

Paul

[Boiler Bill]

I live near Snohomish Washington, We put on a SuperCub flyin every year at Cascade air park. The grass strip is 3000' long and like a lawn. We have short field take off and landing contests every year and all are measured. My friend has a stock motor 170B and gets off the ground in about 300'. Every year he gets beat by his friend who has a 172 with tricycle gear and big tires. The tail on that plane gets right on the ground and thats what gives him the edge. The 170B now has bush wheels on it and he flys on gravel bars near rivers all the time with another friend who is flying a SuperCub. They are both excellent pilots. The 170 does not get off the gravel bars as fast as the cub, but its not far behind him. Being tail heavy probably does not help. Our flyin is the last weekend of June, every year Friday, Sat. and Sunday. Bring your planes and give it a try.

Another note about the 170B. Im not a skilled pilot like most of you, but I did enjoy something when I first purchased my 170B. A instructor friend noticed when we were shooting landings on a paved airfield, That a couple of times I forgot to push in the carb heat or set the trim right ect. He said, stop the plane in the middle of the runway, full stop. Now set the flaps full, pull out the carb heat, put the trim way forward. His point was, don't swet forgetting some of the settings the plane will still fly. Then he said lock up the brakes, full power and get off the brakes. The plane shot up like it was in a elevator, I couldn't believe how it could climb. I would not recomend doing this but it did make me understand how these planes can perform, even when set up wrong. This plane has the 180 h.p engine, wing tips and constant speed prop. which helps. but there all great short field planes stock or not.

[Green Bean]

Yeah, .... we're also measuring takeoff rolls with a micrometer too. I was just conversing theoretically.
The smooth-water takeoff can also be shortened by first roughing up the water (back-taxiing) to get a little air under the float. But I ain't no expurt on floats.... (or anything else really, either!)

George- the invitation is still open, as of yet you haven't responded to visit Alaska this summer, which was sent via (pm).(1/2008).. Maybe you could get a float rating while your here.. Roughing the water isn't always an option, and the aileron is an accepted and recommended procedure on floats. Theory is a good thing, but operational experience is what works, on a daily basis.

[hilltop170]

My friend has a stock motor 170B and gets off the ground in about 300'. Every year he gets beat by his friend who has a 172 with tricycle gear and big tires.

The same thing happened last year at the Valdez, Alaska Fly-in short takeoff contest with the heavy touring class, which includes the 180, 182, 185, and 206. The old 182s with manual flaps and big motors, O-520s, got off quicker than any of the 180s or 185s. The guys who know how to fly the 182s let them accelerate with neutral controls and know when to horse them off. They can rotate farther than the 180s. That trick works on pavement but I wouldn't trade a 180 for a 182 if you're going to do real bush flying, the nose wheel is a liability. Give me a tailwheel when the going gets rough.

[flyguy]

... ( cruise is the least drag and that is a flat attitude ) 2....

Not true. It's actually very high drag, since drag increases as the square of velocity. But we know what you meant.

Obviously there is a hugh paradigm difference in what STOL is to different members of this forum. ...

Ol' Gar's "Kajun Hereatige Dikshunary" doesn't know hooo Hugh Paradigm is... but it ain't know Kajun name!

hoppypottymus, unerware, horse**IT. SEE THAT I KIN SPYEL BIG WORDS TU. EEENYWAY FOR EVER SET OF PARYDIGITS THERE ARE TWO OR MOAR OUTHOUCOMES THAT MITE WORK GUD.

IMA NOT WANTIN TU STIRY UP STUFF EVEN THO IMA EXPERT AT STIRIN UPS UFF

1972 STARTED MY EDUCATION AND LEARNING THE '52s LIKES AND DISLIKES. IF YOU ARE TAKING OFF ON SOFT FIELD YOU BETTER NOT LET THE NOSE HAVE IT'S OWN WAY! SHORT FIELDS, HIGH ALTITUDES, HOT HIGH HUMIDITY ALL FACTOR THE TECHNIQUE THAT YOU WILL WANT TO USE. I HAVE USED THEM ALL AND FOUND TRIM FOR TAIL LOW AND 20' FLAP USUALLY GETS OFF QUICKER ON HARD SURFACES. FOR SOFT OR SHORT FIELD - TRIM -NEUTRAL THEN AT ABOUT THE TIME THE TAIL FLIES POP THE 20'.

[Joe Moilanen]

"My friend has a stock motor 170B and gets off the ground in about 300'. Every year he gets beat by his friend who has a 172 with tricycle gear and big tires."

Boiler Bill, you wouldn't happen to be talking about Karl and Kelly would you??

Joe
4518C

[Boiler Bill]

Hi Joe

Joe you guessed it right again. It was and still is, Karl and Kelley. Infact, I heard Kelley say if Karl isn't going this year, he wouldn't either. Karl just laughs and the bets on again this year.

Everyone is welcome to come, the foods, great, camping. and alot of fun planes.



Bill

[Joe Moilanen]

Karl and Kelly stopped by and visited me on the last day of the year(2007) on their way to Cottonwood Island for a campout. I'll post some pictures of them landing at my 650' strip as soon as I get around to figuring out how to post them.

Joe

Hi Joe

Joe you guessed it right again. It was and still is, Karl and Kelley. Infact, I heard Kelley say if Karl isn't going this year, he wouldn't either. Karl just laughs and the bets on again this year.

Everyone is welcome to come, the foods, great, camping. and alot of fun planes.



Bill

[flyguy]

1. Then get the tail up to reduce drag ( the least drag the faster the acceleration ) ( cruise is the least drag and that is a flat attitude ) 2. When you have the needed speed ( you know from experience and many hours in your plane ) FULL FLAPS and your in ground effect.

. "LEAST DRAG" -V- "FULL FLAPS" IS A OXEYMORON. NO RIGHTYOUS 170B PILOT IS GONNA PUT THEM BARN DOARS DOWN BEFOR STARTIN ON A TAKEOFF ROLL. ITSA LIKE PUTTIN THE SPOILERS UP ON A 747. PUSHIN THE ELEVATOR DOUN TU GIT THE TAIL UP IS A DEFEATIN THIS FORMULA FER LEEST DRAG TU.

HYEAR IS THU FORMULA - A 170 RAGWING - - NO FLAPS TU SPEEK UV - - A 170A - JES BARELY FLAPS,- - A 170B - THRUST REVERSER FLAPS SO U CAN PUT FULL FLAP DOUN ON A RAGWING OR 170A BUT NOT A "B"

AN - ACCELARAYTEN IN A TURN ISA GUD WAY TO FOL UP A GEAR LEG LESSN URE ON WET GRAS.

[hilltop170]

This comment was first posted in "Advise on Bush Flying". Ole Gar, alias flyguy, on Sat Mar 08, 2008 2:18 am requested it be copied in this thread. Here it is;

by hilltop170 on Tue Feb 26, 2008 8:13 am

I went out today and did my version of a "BS eliminator" flight. I did over 15 T.O. & landings to a full stop in my stock O-300-D engine, 76-55 prop, stock wing C-170A with small flaps, 6.00-6 tires, wheelpants, and Cleveland single-puck brakes. I had never done this exact senario before but it both confirmed what I had previously found to be true and surprised me in other ways.

The conditions were OAT 85°, 1700'MSL, paved runway, 30° steady crosswind from the left at 10mph, one person, 28 gal down to 22 gal gas, 4 seats, and no other payload in the plane.

On each takeoff, power was set to full throttle, brakes held until max RPM, then released. Flaps, trim, and method of lift-off were varied.

I have a helicopter airspeed indicator that starts at 10mph indicated and climbs at 5mph increments. 50mph is at about the 4 o'clock position so lots of low speed resolution. The plane will fly at about 35mph indicated, whatever that really is with all the built-in errors, but it is repeatable and indicates the plane will lift off in ground effect (but not climb) well before the white or green arc starts.

Basically what I found was that with the stock C-170A, I can lengthen a take-off run with poor technique but no matter what I did, the best takeoff runs were within 50' of 600' (three landing lights).

The smoothest and shortest ground runs were with the elevator in trail, trim set to just lift the tail, two notches of flap, hold pitch attitude with elevator when the tail just starts to lift, let the plane fly off when it is ready. Anything else lengthened the ground run.

- No-flaps lengthened the run.
- Four notches flap (remember they are the small flaps) lengthened the run.
- Holding the tail on the ground until the plane flew off lengthened the run.
- Trying to horse the plane off early lengthened the run.
- Starting with no flap then pulling two or four notches in just after the tail came up did not shorten the run.
- Lifting the tail with the elevator, with or without flap, then pulling back on the elevator did not shorten the run.

Since I usually try to fly smooth takeoffs and stabilized approaches, I'm sure I was not at optimum proficiency in trying to perfectly time jerking in flaps and horsing the plane off the ground (and neither would anyone else that doesn't do it every day). So I think the exercise was fairly representative of the performance that can be expected under those conditions.

Approaches were flown at 55mph with full flaps, airspeed was held just above the bottom of the white arc although the plane will fly a little below the white arc with power. Landings were all wheel landings and stopped in about the 600' range from touchdown with heavy braking. I'm not a big fan of dragging the plane in with power then chopping it. I can hit my spot consistently much better, brake harder, see over the nose better, crosswind or not, with a wheel landing. This method showed I can land in the same or less distance than the takeoffs and I'm carrying a little safety margin by not being behind the power curve. Of course, considerable changes would have to be made with a soft runway and that's another whole discussion.

I believe the stock plane does not have enough power to horse itself off. It must patiently be allowed to build airspeed until the wing makes enough lift then it will fly itself off. With more horsepower it would accelerate faster and some of the short field techniques would probably work better.

I'm satisfied with the stock engine performance. The stock plane will carry gross weight, take off in about 1000', climb about 500fpm at std conditions, and cruise on 7.2gph at 110mph. That's good enough for me.

It would be interesting to see how some other 170A's compare in performance. How about it guys? Today was a lot of fun and I re-learned a bunch about my plane and its performance.

Big flaps on the 170B will no doubt improve performance but it remains to be seen how much. Maybe some of the 170B guys will go out and try it and let everyone know what they found.

How about one or all of you 180hp Lyc O-360, 210hp Cont IO-360, or 220hp Franklin guys go out and try the different techniques and see what happens? Be sure and let us know how it went.

Everybody has their own ideas on what works best and they're entitled to them. I found out what works best for me in my airplane and that's what I have and will be using. Only two things count in bush flying, either you make it or you don't. Everything else is just opinion.

[GAHorn]

Maybe if you put a little more red paint on that thing..... Or removed all the other colors.....