Flight Performance and Planning (Mass and Balance, Performance, Flight Planning)
What the exam tests
Mass and balance, takeoff and landing performance, and flight planning: CG limits, runway distance definitions, climb gradients and fuel policy.
Core rules
- Mass is the sum of items; moment = mass × arm; CG = total moment / total mass.
- %MAC = (CG − LEMAC) / MAC × 100.
- Takeoff mass = zero-fuel mass + takeoff fuel; landing mass = takeoff mass − trip fuel.
- TORA is runway length; TODA adds clearway; ASDA adds stopway.
- Fuel: taxi, trip, contingency (usually 5%), alternate, final reserve, additional, tankering.
- Second-segment climb gradient is net 2.4% for twins, 2.7% for trijets, 3.0% for quads under CS/FAR 25.
Worked example
Basic mass 2,000 kg at arm 2.0 m; payload 1,000 kg at arm 5.0 m. Moment = 4,000 + 5,000 = 9,000 kg·m; mass = 3,000 kg; CG = 3.0 m. With LEMAC 1.0 m and MAC 4.0 m, %MAC = (3.0 − 1.0)/4.0 × 100 = 50%.
Traps
Treating %MAC as a length; forgetting to subtract trip fuel before checking landing mass; confusing V1 with VR; and assuming a contaminated runway performs like a dry one.