Quantities are dimensionless unless otherwise stated. Symbols and abbreviations not listed below are used only locally and defined in the text. Subscripts 1 and 2 denote conditions at the start and end of a segment respectively. Overbars denote segment mean values, i.e. average of start and end values.
Average acceleration, ft/s2
Maximum acceleration available, ft/s2
Flap coefficients
Engine thrust coefficients
Net thrust per engine, lbf
Corrected net thrust per engine, lbf
Climb gradient
Engine-out climb gradient
Mean runway gradient, positive uphill
Gravitational acceleration, ft/s2
International Standard Atmosphere
No of engines supplying thrust
Drag-to-lift ratio CD/CL
Segment rate of climb (ft/min)
Ground distance covered along ground track, ft
Take-off distance into an 8 kt headwind, ft
Take-off distance corrected for w and GR , ft
Take-off distance into headwind w, ft
Air temperature, °C
Breakpoint temperature, °C
Groundspeed, kt
Calibrated airpeed, kt
True airspeed, kt
Aeroplane weight, lb
Headwind speed, kt
Still air segment length projected onto ground track, ft
Segment length ground projection corrected for headwind, ft
p/po , the ratio of the ambient air pressure at the aeroplane to the standard air pressure at mean sea level: po = 101,325 kPa (or 1 013,25 mb)
Bank angle, radians
Climb/descent angle, radians
(T + 273,15)/(T0 + 273,15) the ratio of the air temperature at altitude to the standard air temperature at mean sea level: T0 = 15,0 °C
ρ/ρ0 = Ratio of air density at altitude to mean sea level value (also, σ = δ/θ)