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Bert Pieke

Duke take-off speed

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According to the charts, the Duke should take off at about 95 knots... but mine likes to accelerate to 120 knotsbefore lifting off. This is with one notch of flaps, trim at +15 degrees, and nobody in the rear seats.Anyone who can lift off below 100 knots, please tell me how... :(

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I canOne notch of flaps...Hold brakes, full throttle, rotate at around 90-95...wheels off the ground by 100ish

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According to the charts, the Duke should take off at about 95 knots... but mine likes to accelerate to 120 knotsbefore lifting off. This is with one notch of flaps, trim at +15 degrees, and nobody in the rear seats.
That sounds about correct. Blue line + 5 knots for this Duke is about 115 knots, which is the speed at which I rotate.

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I find with a bit more trim (more than 15) and 1 notch flaps I get off the ground well under 100 knots.

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I find with a bit more trim (more than 15) and 1 notch flaps I get off the ground well under 100 knots.
yeah that's where I'm at - maybe I have too much trim in

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This is where the MSFS flight-model shows weakness. Trim can effect not just control pressures.. but actual performance. If you were motoring down the runway at 120+ knots.. you'd be holding it down on the nose-wheel , like a wheel-barrow :( That's faster than VyYou should be lifting the nose at ~95kias

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It's very dependent on load. If you have extra passengers in the back and a lot of fuel, she's a little nose light and therefore wants to rotate sooner, but of course that's not a good idea. Conversely with a light load she's a little nose heavy so needs either more trim or more stick. I couldn't find any flap recommendations in the POH but I reckon one notch flaps for all take offs is better.Best Regards,Rob - RealAir

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It's very dependent on load. If you have extra passengers in the back and a lot of fuel, she's a little nose light and therefore wants to rotate sooner, but of course that's not a good idea. Conversely with a light load she's a little nose heavy so needs either more trim or more stick. I couldn't find any flap recommendations in the POH but I reckon one notch flaps for all take offs is better.Best Regards,Rob - RealAir
I have no knowledge of the Dukes(other than their unreal maintenance costs)-but the Bonanza and Baron do not use flaps for takeoff-even short field.I have found fs seems to have limitations here. For instance-on the Baron rw once you hit red line the plane wants to jump off-you have to hold it a little more-and then it really jumps-it really wants to fly.

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I have no knowledge of the Dukes(other than their unreal maintenance costs)-but the Bonanza and Baron do not use flaps for takeoff-even short field.I have found fs seems to have limitations here. For instance-on the Baron rw once you hit red line the plane wants to jump off-you have to hold it a little more-and then it really jumps-it really wants to fly.
You don't want to use flaps in the Duke on takeoff either. While the POH's for the late 60's and early 70's even would have some light to medium twins using flaps on takeoff it was a recipe for disaster if you lost an engine at a critical time. Lose an engine right after liftoff in that configuration and at less than 100 KIAS and I doubt you would keep the real aircraft off the ground. No flaps and 92 to 98 KIAS with about 15 degrees up trim should work fine, hold the nose down to accelerate retract the gear and maintain 120 indicated on initial climb, passing through 1,000' AGL lower the nose to accelerate to 140 indicated as you adjust power settings to climb. Running a Duke at high power settings for extended periods is quite costly and I don't mean fuel costs.

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Conversely with a light load she's a little nose heavy so needs either more trim or more stick.
OK, I think I've got it now. I just was not decisive enough with the yoke.At 95 kts I now pull back on the yoke, and at 100 I'm off the ground.Thanks for the help! :(

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