Flight Performance and Planning
Flight Performance and Planning
This domain tests mass and balance, takeoff and landing performance, fuel planning, and the effect of Kuwait’s heat and elevation on aircraft capability. Performance is not a single chart reading: weight, CG, pressure altitude, temperature, wind, runway slope and surface all interact.
Core rules
- Calculate mass and CG before every flight. Maximum takeoff/landing mass and CG limits are certificated limits, not suggestions.
- Convert aerodrome elevation and QNH to pressure altitude; then use temperature to find density altitude.
- Use the aircraft flight manual charts for the actual weight, flap setting, runway and conditions. Add contingency for wind, runway surface and pilot technique.
- Fuel planning must include taxi, trip, reserve and diversion fuel. Kuwait’s hot climate increases fuel burn and reduces climb performance.
- A forward CG increases stability but can reduce elevator authority; an aft CG reduces stability and may make stall recovery difficult.
Worked example
Aerodrome elevation 200 ft, QNH 1013 hPa, OAT 45°C. Pressure altitude is 200 ft. ISA temperature at 200 ft is about 14.6°C. Using the approximation density altitude ≈ pressure altitude + 120 × (OAT − ISA), the result is 200 + 120 × (45 − 14.6) ≈ 3,850 ft. The aircraft performs as if at 3,850 ft: longer takeoff roll, lower climb rate and reduced engine power. Use the AFM chart for 3,850 ft, not 200 ft.
Traps that cost marks
Using QNH instead of pressure altitude; using indicated rather than density altitude; ignoring wind and runway slope; planning fuel at gross weight when actual weight is lower; and treating a CG within limits as automatically safe for performance.