IHS ESDU First approximation to take-off field length of multi-engined transport aeroplanes. 76011

ESDU 76011 gives a method, obtained by correlating flight manual information for 36 aircraft powered by turbo-jet, turbo-fan, turbo-prop or piston engines, for estimating both unfactored all engines operating distance to 35 ft and the balanced field length. The correlation was found to encompass within 8 per cent some 95 per cent of the data. Both distances are correlated using second segment climb gradient as one parameter and a second parameter involving aircraft weight, lift coefficient at take-off safety speed, and thrust. However, for balanced field length a second correlation is given taking into account different levels of deceleration in the stopping phase. A parameter is added to the correlation including the ratio decision speed/take-off safety speed; a correlation for that parameter is also included depending on the average deceleration available during the stopping phase and a table is given of typical values depending on runway condition and braking methods available.