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Operation 29
climb for zero power margin; or airspeed for best climb rate or best climb angle with maximum rate of
climb for zero power margin. Not implemented is a maximum-effort calculation of maximum flight-path
acceleration for zero power margin and specified climb angle; this calculation would require integration
of the acceleration as a function of flight speed. For the climb segment, the input VCL is the magnitude
of the aircraft velocity relative to the air, and the climb angle relative to the horizontal is θV = γ + γG.
Hence from the maximum-effort calculation, the climb angle relative to the ground is γ = θV − γG and
the ground speed is Vground = VCL cos γ − Vw (from the wind speed Vw). Then
tCL = sCL/Vground
sCL =(h− hlast)/ tan γ
hCL = h
wCL = ˙wf tCL
are the time, ground distance, height, and fuel burned.
4–4 Flight State
A flight state is defined for each flight condition (sizing-task design conditions and flight performance
analysis) and for each mission segment. The following parameters are required:
a) Speed: flight speed and vertical rate of climb, with the following options:
1) Specify horizontal speed (or forward speed or velocity magnitude), rate
of climb (or climb angle), and sideslip angle.
2) Hover or vertical flight (input vertical rate of climb; climb angle 0 or
±90 degrees).
3) Left or right sideward flight (input velocity and rate of climb; sideslip
angle ±90 degrees).
4) Rearward flight (input velocity and rate of climb; sideslip angle 180
degrees).
b) Aircraft motion.
1) Pitch and roll angles (Aircraft values or flight-state input; initial values
for trim variables, fixed otherwise).
2) Turn, pull-up, or linear acceleration.
c) Altitude: For mission segment, optionally input, or from last mission segment;
climb segment end altitude from next segment.
d) Atmosphere:
1) Standard day at specified altitude.
2) Standard day plus temperature increment.
3) Standard day and specified temperature.
4) Input density and temperature.
5) Input density, speed of sound, and viscosity.
e) Height of landing gear above ground level. Landing gear state (extended or
retracted).