Flight Performance and Planning (Mass and Balance, Performance)
Scope
Flight Performance and Planning tests mass and balance, takeoff and landing distance, climb, density altitude, fuel planning, and the use of aircraft performance data. Philippine heat and high-elevation strips make density altitude a practical exam theme.
Core rules
- Weight must not exceed maximum takeoff, landing, or zero-fuel limits; CG must remain inside the forward and aft limits for the whole flight.
- Use moment = weight × arm; total moment divided by total weight gives CG.
- Performance decreases with altitude, temperature, and humidity; increase takeoff/landing distance and reduce climb rate.
- Fuel planning includes taxi, trip, reserve, and contingency; do not plan to land with less than the required reserve.
Worked example
Empty weight 1,600 lb at arm 39.0 in, pilot 170 lb at 37.0 in, fuel 240 lb at 48.0 in, baggage 30 lb at 95.0 in. Moments: 62,400 + 6,290 + 11,520 + 2,850 = 83,060 lb-in. Total weight = 2,040 lb. CG = 83,060 ÷ 2,040 = 40.7 in. If the envelope allows 35.0–47.3 in, the loading is within limits, but still check maximum weight and each compartment limit.
Traps
Using the wrong arm, forgetting fuel density (avgas is about 6 lb/US gal), or leaving baggage out of the final total. A forward CG can increase landing distance; an aft CG reduces stability. Density altitude is not just field elevation.