Hot: High TAS (inertial speed) is required for same IAS, and
Reduced thrust available if OAT above flat rating
High: Lower OAT, but engine may reach N1 or EPR limit, so SL thrust may
not be maintained, and
Less dense air means high GS (inertial speed) is required for same IAS
In each case, the higher inertial speed required means the momentum added by the engines (= mass x velocity) is greater than the SL Std Day case. At same TOGW, same thrust, the TO roll is thus longer. If thrust is reduced, even MORE TO roll is needed.
Last edited by barit1; 10th December 2006 at 04:20.