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Fritz Bayerlein

Breakaway power in the 757-200 seems awfully ineffective (fix)

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Hey guys,I've been using 40% to 45% N1 as breakaway power (this is more or less standard in all jet-powered aircraft) and yet even at light loads the aircraft doesn't want to get moving. It seems abnormally slow on the taxi and requires a lot of thrust.Now I know FS's stock rolling friction is completely unreal, but short of implimenting the rolling friction fix sim1.dll that is not officially supported, I think a simple fix would be to increase the thrust curves for the bottom-end mach numbers.I went ahead and made some changes to 1506 table(Rob Young would get it!) in order to improve taxi performance. What it appears is there was a mistake made with a couple low-end curves being flip-flopped. I'd be more than happy to send the files over your way so you can check them over and possibly impliment them into your next patch if you'd like! Thanks,Shane

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Shane,This was the subject of great debate during development - as you know you cant have it good on the ground and in the air without hacking and replacing sim1.dll; something PSS wont do since it would be in breach of copyright.I will however alert Rob to your post.

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Yup, way too much power needed! The company I fly for restricts the maximum breakaway power to 1.1EPR. This is normally more than enough to get the aircraft moving at up to MTOW.Mike

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At SL STD my RR RB211-535E4B idle at EPR 1.14, N1 36.6, and EGT 397. at ramp max gross weight of 256,000Lb, it gradually accelerated on level runway with slight addition of thrust, and when above 10Kt ground speed, retained speed with idle to 1%N1 above idle.>Yup, way too much power needed! The company I fly for>restricts the maximum breakaway power to 1.1EPR. This is>normally more than enough to get the aircraft moving at up to>MTOW.>>Mike

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In the .cfg the RB-211 is rated at over 43000lbs of thrust whereas the PW2040 model I was using is sans 6000lbs of thrust. Maybe your RB211s taxis as it should but the PW2040 model does not because of the issue I mentioned previously.

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No, but as I said earlier, the issue is more one of limits in the FDE available with FS9. From our discussions during development (since this was brought up) if you make the plane "less sticky" and able to move at the correct breakoff point on the ground you then have issues in the air. The reverse is also true.Since we prefer to simulate a model in flight, and remembering that the 757 is already a rocket in the air, guess which option was taken.

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