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icemarkom

Overspeed on Takeoff

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To everyone experiencing this- try loading your plane a little bit more. I thought I had the problem with this and tonightIi decided to try my shiny 777 with a 100% load. Perfect takeoff performance.

 

 

 

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Or, Derate. Assumed temp 65°C or Derate 2.

 

Either that or rotate over a period of 5 seconds to a 23°+ pitch up ;)

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See - I haven't tried 23 degree pitch. I tried derate 2, alas it was not enough. 461.000 lbs do the trick, apparently.

 

On my way to KLAS on VATSIM as we speak if anyone wants to o serve me mess up the visual landing in about 35 min ;-)

 

 

 

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So, everyone does realize that it's not just "pitch up and throttle the engines to match speed," right?

 

  • As described in the FCTM (paraphrased here):
  • Accelerate down the runway
  • Rotate at VR, ensuring you do not overrotate and hit the tail
  • Leaving the ground, pitch up to maintain the commanded speed (follow the FD)
  • The takeoff profile is a pitch for speed mode (as is most of the climb), so your throttles will be set on the rated thrust for the particular part of the profile, and you point your nose up to maintain this speed.

 

Overspeeding on takeoff will be easier at lighter weights (particularly with no derate), but that points more toward an issue in technique, rather than an issue with the plane.  Pitch for speed, no matter what that pitch is.  Contrary to everyone's FSPassengers upbringing (or lapses in physics knowledge), high vertical speed does not cause discomfort.

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Don't tell some peolpe are using full power on takeoff! What airline does that? derate, derate, derate! I saw a resonable solution if the problem still persists. Check out Frooglesim's new video. the idea is to create another speed restriction in the vnav page on the fmc. The default on is 250kt at 10000ft, so you can add another say 230kt at 5000ft to ensure it won't break the original restriction:http://www.youtube.com/watch?v=QcLkByuxPHs&feature=c4-overview&list=UUCcyPyTfN8LEVHQojHkR-aA

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hmm,

 

i could of swore i was flying an f18, or jet assisted take off something on this guy. :P

 

 

 

Thanks,

 

 

Andrei.

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The FCTM actually says that at low weights it is highly recommended to both de-rate, and/or assumed temp de-rate as well. The reason is not to do with acceleration rate, but in fact controlability in the event of engine failure.

 

Best regards,

Robin.

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