On Mon, 03 Sep 2007 15:18:03 -0600, Newps wrote:



Roger (K8RI) wrote:

On Sat, 01 Sep 2007 21:54:03 -0600, Newps wrote:



Roger (K8RI) wrote:



"I think" meaning I don't know for sure, that flaps slow the
acceleration enough that nothing is gained in distance by using them.

It reduces ground roll by 20%.


It might get me into ground effect a bit earlier, but the end result
would take more distance to clear thatl 50 foot obstical.

That is not the case. You clear 50 feet sooner with flaps than without.

I quote from the "American Bonanza Society Pilot Proficiency Training
manual:

Short Field Takeoffs:

1: Align the aircraft with the runway, Apply full power prior to brake
release. "FLAPS SHOULD BE UP" (Emphasis mine) unless otherwise stated
in the POH for the specific aircraft.

2. Accelerate with pitch attitude near neutral to Vx.

3. Rotate positively at Vx and stay at Vx until the obstacle is
cleared.

4. As noted elsewhere and in this manual the drag of the extended gear
at Vx has little or no effect on climb performance. Accordingly, on
climbouts from short field takeoffs The landing gear should not be
retracted until obstacles and terrain are cleared. Then raise the gear
and accelerate to Vy.


A lot sooner, 33% in fact. A Bonanza with a 520 at 2800 pounds,

Not according to the manual.

5000 feet and 32 degrees gets these results: Flaps 20...Lift off in 876
feet and thru 50 feet in 1200 feet. No flaps...Lift off in 944 feet and
thru 50 feet in 1600 feet. There will be minor differences among the
various Bonanza models but all will perform basically the same.