short takeoff best tech

[Dravenelle]

hi

i need the technic for short takeoff

i have a kitfox 2 with a hks 60 hp


full flap? full elevator? full brake with full power?

Dave

[jtpitkin06]

Short field take off is a relative term. A fully loaded 767 on a 10,000 foot runway is a short field take off.

With certified aircraft you could go to your manual and look ip the best angle and best rate speeds. But with experimental aircraft you have to do some flight testing. So let's get some information for YOUR aircraft.

The place to start is 3000 feet above ground level.
Put your aircraft in a full power climb and note the pitch angle and indicated airspeed where you get the first indication of a stall. Do this clean and with flaps. We will note this pitch angle as the never exceed pitch.

Next perform a flight test to plot the best ANGLE of climb airspeed. Make a chart with climb rate on the left side and airspeed along the bottom. Record the rate of climb for different climb speeds, about every five knots will do. Also record the pitch angle or note where the cowling is in relation to the horizon. Connect the dots from your test climb speeds. The best RATE airspeed is the top of the curved line. To find the best ANGLE draw a line from 0,0 to lay along the left side of the plot line. Read straight down from the point where the lines intersect to find the best ANGLE indicated airspeed. Do this for clean and with flaps.

You will probably discover the airplane will fly slower with partial flaps than clean but the climb rate will be less. Compare your plotted lines to see if partial flaps will give a steeper climb than a clean wing.

It is possible your airplane may climb steeper with no flaps. If your runway has an obstacle you are usually better off using a bit more runway for improved climb.

If your runway is short with no obstacles you are usually better off using partial flaps with less climb performance.

Armed with this information you can now try it on take off. Your target speed is the best ANGLE of climb speed for the flap setting used.

All we need to do now is get to that speed.

Set the flaps for the configuration that gives the best angle of climb plotted in your climb chart. I do not recommend charging down a runway with the flaps up and popping flaps in at the last moment. There is no evidence that your takeoff roll will be significantly less. There are lots of bent airplanes as evidence that it is not a good idea to change configuration during takeoff or landing.

If you can, use a rolling takeoff. As you turn into position keep the momentum going and apply full power as you get lined up. If this is not possible, line up on the runway and hold your brakes. Apply as much power as possible without the tires dragging. Release brakes and add the rest of the power.

Tail draggers will have neutral elevator and normally let the tail rise on its own before lift off or let the airplane fly off in three point. Establish the best angle climb pitch. The aircraft will accelerate in ground effect and then climb at best angle.

Nose wheel aircraft will have neutral elevator or slightly back stick if the field is soft.

Approximately 10 knots below best angle speed start a smooth rotation to best angle pitch. Hold that pitch as the aircraft lifts off in ground effect. The aircraft will accelerate in ground effect and climb at best angle.

Do not chase airspeed in the climb. A constant pitch will give better performance than trying to nail an airspeed to plus or minus 2 or3 knots.

When clear of the obstacles smoothly lower the nose to your best rate pitch attitude.

Now... A word about obstacle takeoffs. I see it all the time at my local airport. A small aircraft takes off and climbs steeply to 150 feet then lowers the nose to accelerate while losing 50 feet or more. Do not chase the airspeed. When you are clear of the obstacles, accelerate, but continue climbing. Do not drop the nose below your best rate of climb pitch.

When you practice all the above you will likely be solo. Do not expect the aircraft to perform the same when loaded. The speeds will be higher when the aircraft is heavier. The pitch angles will be lower when heavier. So don't throw a 200 pound passenger in the airplane and announce,"Watch this!" Be conservative until you know what the aircraft will do when loaded.

The most important thing is to practice. Do lots of takeoffs on a long runway to hone your technique before you need to do it on a short runway.

Fly fun Fly safe

John
Greenville, Tx

[SS7Flyer]

John I am guessing by your picture you must be a professional pilot. You should take your airline hat off when talking about Kitfoxes Your putting WAAAYYYYY too much thought into this and taking all the fun out of it!!

My short field takeoff technique is put in around half flaps...go to full power, full down elevator as soon as the tail lifts neutralize the stick....count...One...Two...three...Pull on full flaps and it'll jump off the ground. As soon as I build a little bit of speed I drop the flaps out and fly away. Heavy I use the same technique I just count a little bit higher before pulling it off. If you pull to early you'll drag the tail a little ways making your take off roll longer than it should be so the timing is pretty important.

Try experimenting with flaps I think you'll be pleasantly surprised....

If you watch the guys at the Valdez STOL competition in this video they drop their flaps to break ground no matter what kind of plane they are in. Some of these guys are the best in the world at what they do.

http://youtu.be/F9EnVah07k0

[jtpitkin06]

ss,



No question that the Valdez pilots are the best at what they do. Unfortunately, stunt flying has its price. They bend a few airplanes each year doing these takeoffs and occasionally flip on their backs doing short field landings. So for the average pilot, I can’t recommend changing configuration during the takeoff roll. If the flaps don’t lock in the detent and suddenly retract, we have an oopsie-daisy and maybe a bent airplane. Flaps also induce a pitching moment.


Does popping flaps really make for a shorter takeoff? Find an experienced CFI to go along with you and try your method popping flaps technique several times and note the takeoff distances. Then do the same with preset flaps. I would be surprised if you see a significant difference in takeoff distance. Even if you get off a few feet earlier by popping the flaps, the preset configuration is safer.


If my postings read like too much thought went into them, there is a reason. I need to be cautious when posting flight instruction on a forum. If I suggest a method that deviates from standard practices and someone crashes while doing it, the lawyers come after me. Even if it was a casual forum like this one. So I’m not really standing on a safety soapbox while thumping the AIM, I’m just checking my six to make sure I don’t get one up the tailpipe.


However, with 44 years of flying in the logbooks I still hope to pass on some of my experiences to the next generation of aviators. Some of it will be way to technical and some of it way too basic and boring. If I help someone… that makes it all worthwhile. So, the overly long posts will probably continue.


The picture of me was taken Oct 31, 2008. Final flight AAL. B-767 MIA-SFO.


John

[SkySteve]

Yep, John. I'm certain you're right. And if I had to give the book answer I'd give the one you gave.
However, here in the mountainous west, SS7Flyer and I use the same technique. Maybe it's just a small town/short airstrip thing.

[Dravenelle]

thank's
guy

i make some test

Dave

[SkyPirate]

Kitfox 2 i landed on a sand bar 75 foot long in Cape Cod with room to spare, then tailed her back to the edge, powered up brakes on, tail up, let off the brakes to get her rolling but keep enough to hold tail up until your airspeed exceeds 28/30, i used no flaps, ( don't let the tail drop) airspeed hit 38 and lift off but not too steep of a climb stay in ground effect until air speed was above 50 climb out

[n85ae]

I'm not sure John's response is a bad one. I got rather aggressive with mine
in the past and after my 22 degrees flaperon induced pitch over (i.e. tail
plane stall, or other similar aerobatic maneuver) where I almost killed
myself, my flying has been a bit more careful. I also have a net in the
cargo bay so all my gear stays off the instrument panel and ceiling for
future flights like that ...

You don't get to make too many big mistakes in airplanes ...

Also never trust the other guy. The guy who reports directly over the city
and 500 ft. lower. Is in fact just north of the city converging on you at
your same altitude exactly where you just reported you are, which he
acknowledged.

Regards,
Jeff

John I am guessing by your picture you must be a professional pilot. You should take your airline hat off when talking about Kitfoxes Your putting WAAAYYYYY too much thought into this and taking all the fun out of it!!

[HighWing]

I just finished helping a friend work on his Light Squared. He confessed he was more a flyer than a builder. I confess, I am more a builder than a flyer.

The reason I mention this is because in everything there are some who can and some who can't, some with better skills here and some with better skills there. John's method is Spot on. Others are spot on as well, but maybe not for everyone. Not that the airplane won't do it, but maybe some pilots can't. Then again, we have tailwheel and tricycle, different models, loading and CGs. I doubt in the world of airplane adventure one size fits all. Got a buddy who dinged his airplanes in the high mountains pushing the envelope landing with no way to trailer it out. adrenaline rush? - you bet, grief? - right again.

I often think of the father of one of my dental assistants. He failed his check ride four times before he finally passed. Then on his first passenger flight four people died and on takeoff no less.

As Jeff suggests, be careful.

[Rmendler]

I am relatively new to the fixed wing community, I'm a helicopter pilot so "interesting" approaches and landings are normal for me.

I find my skills to be under developed thus far for real stol work in my model iv.

I have had the opportunity to fly with many great pilots and the one thing I keep hearing is "feel your airplane" and "know your limits". I push the envelope sometimes, but not by much at all because I do not "feel" the airplane yet. My ultimate goal is to land in the field in front of my house, it's roughly 600ft but its a rough rollout and difficult approach. I know the airplane can do it but I cannot. I can do some gnarly approaches in helicopters because I "feel" the copter, it is comfortable for me. I am not comfortable in my airplane yet.

I climb to a good altitude (3,000ft agl or so) and practice slow approaches and landings just like you would in training for aerobatics. I slowly lower the altitude. If I make a mistake I start back at the original altitude until I get it perfect again then work my way down.

It may sound overboard but I read the technique in an aerobatics book back when I thought I could handle a Pitts special, haha. It's not full proof but it help you build a save level of confidence without becoming cocky

Drinking Rant End /