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In a message dated 2/7/2003 5:28:04 PM Central Standard Time, Lee.Metcalfe@jocoks.com writes:
I remember someone (Grayhawk?) saying he uses incremental flap extensions to slow down when entering the pattern.
Lee "Q-Tip" Metcalfe
Oui! Ya! Si! Da! Hai!
Q-tippy,
I have flown an experiment at 153 KIAS and taking the flaps out of reflex (about 7 degrees down). 15 Kt slowdown (+ or -, need more experimentation), 2.4 degree nose down pitch change and big trim adujstment in order to maintain level flight. I was using marks placed on the outboard edge of the left flap and I doubt that the inboard flap reached the same down setting -- go to your airplane, mark the outboard edge where it passes under the top skin trailing edge, place about 10 pounds of upward lift on the edge and notice how much twist occurs without the inboard edge moving at all (after lash is taken up).
I normally do not extend any flap until the power reduction (maybe 17-18 inches MP) slows me to about 140 or so KIAS in level flight. Then I start ticking them down to "takeoff" (about 10 degrees), thus pretty quickly reaching the magic 120 KIAS - down goes the gear and another 15 KIAS drop in speed- the rest is history (except for the wheelless luge ride).
Grayhawk AKA Scott Krueger
N92EX
PS: Feel free to drop the flaps at Vne and report back (if possible). We are all waiting to see how it flies without any flaps at all. Really, I don't think these things can take the twist - It's too bad that the flap actuator wasn't placed closer to BL50.
PPS - From an e-mail previously sent:
It has been claimed that the reflex/no-reflex flap difference has little affect on speed, perhaps 2-3 mph. My feeling was that is was greater since I use small flap increments to knock down the speed when approaching an airport. It was also postulated that I may see a greater indicated air speed difference that may be due solely to a change in the airflow over the fuselage near the static ports. Thus, I should look at ground speeds. The following experiment was performed today.
-The static ports on my 320 are in the Lancair recommended location.
-The flap was marked at 7* down from the faired in reflex position.
-A target test speed of 160 Kts would be used to lessen the twist applied to the outboard end of the flap.
-A digital level was carried aloft for additional information and coordination with AOA (Proprietary Software) readings.
-All data collected in trimmed level flight with autopilot and alt hold engaged.
The following baseline was used:
6500 ft (6110 p alt), -7*C, 25.1" MP, 2490 RPM, 180 KIAS, 192 KTAS
Longeron Angle = +0.6*, wing AOA = 1.9, Tail AOA = -0.15*
At 5500 ft, heading East, 20.5 " MP, 2380 RPM
In Reflex (-7*) - 153 KIAS, 169 GS - Longeron= +1.2*, wing AOA = 2.7, Tail AOA = -.45*
No Reflex (0*) - 142 KIAS, 154 GS - Longeron= -1.2*, wing AOA = 1.0, Tail AOA = -1.95*
11 Kts indicated slower, 15 Kts slower over the ground.
At 5500 ft heading West, 20.5" MP, 2380 RPM
In Reflex (-7*) - 153 KIAS, 155 GS - Longeron= +1.0*, wing AOA = 2.7, Tail AOA = -.25*
No Reflex (0*) - 144 KIAS, 144 GS - Longeron= -1.2*, wing AOA = 1.0, Tail AOA = -1.95*
9 Kts indicated slower, 11 Kts slower over the ground.
The wing has a tremendous pitching moment when the flap is engaged, with quite a bit of nose up trim (tail down load) needed to fly level.
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