Short Field Takeoff
The purpose of a short field takeoff is to get the airplane off the ground and high enough to clear a 50′ obstacle in the shortest distance required. Now not all obstacles are created equally (and not all are 50′ tall), however you will commonly hear this 50′ height used in aviation performance charts and on your written exam. Play along with us and let’s just assume for our purposes that all the obstacles we’ll be dealing with here are 50′ tall.
The video above details the proper procedure for doing a short field takeoff. A few things you will want to keep in mind are:
- Use ALL the available runway, don’t start your takeoff 75′ down the runway after getting lined up. Line up on the earliest part of the runway you can to have maximum takeoff performance.
- Apply full power before releasing the brakes. This is twofold, one, you want to have the engine spooled up producing thrust right when you release the brakes and start eating up valuable runway distance. Two, you want to ensure the engine is producing full power and operating properly before you try to take off on a very short runway with an obstacle ahead of you.
- Check your instruments before releasing the brakes (oil temp, oil pressure, static engine RPM, etc.)
- Use the appropriate flap setting for takeoff according to your POH
- Follow the procedure for a short field takeoff exactly as it is written in your POH, the default procedure for many airplanes is:
- Apply full power, release brakes
- Do not use any back pressure or induce any drag until rotate speed
- Rotate at Vr, Climb out at Vx until clearing your obstacle, then accelerate to Vy, then begin retracting your flaps.
- Do not retract the flaps too soon!
BE AWARE OF GROUND EFFECT!
Ground effect is caused by a reduction of wingtip vorticies, and occurs anywhere up to approximately one wingspan above the ground. Down-wash can hit the ground push the wing from below, forming what feels like a cushion. Keep in mind that:
- Carrying any excess airspeed into the flare will substantially lengthen the amount of time you float. It is much easier to bleed off airspeed in the descent as compared to in the flare.
- The aircraft will lift off the runway and “fly” in ground effect at a lower airspeed than that required to fly out of ground effect.