Flight Performance and Planning
Performance
Takeoff and landing performance depends on mass, pressure altitude, temperature, wind, slope and runway condition. Density altitude combines pressure altitude and temperature; high, hot and humid conditions reduce performance. V1 is the decision speed, VR rotation, V2 takeoff safety speed. Landing distance required must fit the available distance with the prescribed factors.
Mass and balance
Moment = mass × arm from the datum. CG = total moment / total mass. The CG must stay within limits for takeoff, in flight and landing; forward CG increases stall speed and pitch force, aft CG reduces stability.
Fuel planning
A typical plan is taxi + trip + contingency + alternate + final reserve + extra. Final reserve is protected; contingency is not a substitute.
Worked example
Empty mass 1200 kg at arm 2.5 m; load 200 kg at arm 3.5 m. Moments: 1200 × 2.5 = 3000; 200 × 3.5 = 700; total 3700 kg·m; total mass 1400 kg; CG = 3700 / 1400 = 2.64 m. The load moves the CG aft because its arm is greater than the original CG.
Traps
Using pressure altitude instead of density altitude; forgetting landing mass when checking landing CG; treating V1 as a fixed speed for all runways; ignoring slope and contamination.