Flight performance, planning and loading
Performance, planning and loading
The exam tests whether you can move between chart, calculation and regulatory limit: V-speeds, density altitude, take-off/landing distance, climb, fuel reserves, and the weight-and-balance envelope.
Core rules
- V-speeds: Vne never exceed; Vno normal operating; Va manoeuvring (decreases with weight); Vfe flap extend; Vle gear extend; Vx best angle; Vy best rate; Vmc minimum control speed (multi-engine).
- Load factor n = 1/cos(bank) in a level turn; stall speed rises with √n. At 60° bank n = 2, so Vs increases by 1.41.
- Density altitude: high temperature, high elevation and high humidity reduce performance; use pressure altitude and temperature on the chart.
- Weight and balance: moment = weight × arm; CG = total moment / total weight. Check maximum take-off, landing and zero-fuel weights.
- Fuel plan: taxi, trip, contingency, alternate, final reserve; do not plan to land with less than final reserve.
- Take-off/landing distances: apply wind, slope, surface and obstacle corrections in the order the chart specifies.
Worked example
Empty weight 1,500 lb at 40 in = 60,000 lb·in; pilot 170 lb at 37 in = 6,290; fuel 300 lb at 48 in = 14,400; baggage 50 lb at 95 in = 4,750. Total weight = 2,020 lb; total moment = 85,440 lb·in; CG = 42.3 in. Compare with the forward and aft limits at 2,020 lb.
Traps
Using IAS where the chart wants TAS; forgetting zero-fuel weight; mixing lb and kg; entering pressure altitude as indicated altitude; ignoring runway slope; and applying wind correction in the wrong direction.