Disagree. I fly light piston twins so I:
* Rotate at the speed specified in the manual to achieve Vtoss by 50'.
Rationale: Vmcg & Vmca establish a lower limit for rotating. Vr gives a buffer above this. Achieving Vtoss is part of achieving performance chart figures. Anything faster wastes some of the chemical energy we're trying to convert into potential & kinetic energy.
* Gear up not before Vxse on long runways where a re-land is still feasable. If a short runway then gear up as soon as positive climb established.
NB: 'Gear up' is my change over point between trying to continue flight if an engine fails or accepting a controlled forced landing.
Rationale: The a/c is not certified to give a guaranteed performance in the take off configuration. Using a long runway gives the opportunity to land on after a failure. Once a land on is not possible then leaving the wheels down any longer than necessary wastes some of that precious chemical to kinetic/potential energy conversion.
Conversly, getting the wheels up too early ie before at least Vxse leads to a lack of performance due wrong speed + landing on the belly.
Given adequate runway length then delaying to Vxse leaves open the ability to land while below a critical performance speed and having achieved that performance speed to enable continued flight.
If a short runway that doesn't allow a land-on option then leaving the gear down any longer than necessary wastes some of that precious energy.
* Climb at Vy until a safe height for single engine manoevring is achieved. Vx if obstacle clearance is required.
Rationale: Vy gives the most least wasteful conversion of fuel energy to altitude/speed. Any faster wastes more energy due to increasing drag. Ditto slower. Gaining more speed (kinetic energy) requires increasingly more energy for each extra knot. Gaining altitude the energy cost is constant per foot gained (ignoring the small Ke gain due TAS effects).
* Cruise climb once above LSALT.
Last edited by Tinstaafl; 20th Apr 2003 at 01:08.