Flight Performance and Planning
Performance fundamentals
Performance questions are won by sorting the variables before reading the chart. Takeoff and landing distance depend on mass, pressure altitude, temperature, wind, runway slope, surface condition and configuration. Density altitude is the master variable for both engine and wing: high, hot and humid means longer. Know the declared distances: TORA, TODA, ASDA and LDA, and do not confuse clearway with stopway.
Mass and balance
Compute mass, then moment (mass × arm), then CG = total moment divided by total mass. Check the CG stays inside the forward and aft limits at takeoff, in flight as fuel burns, and at landing. A forward CG raises stall speed and reduces range; an aft CG reduces stability. Check zero fuel mass separately from takeoff mass.
Planning
Fuel planning covers taxi, trip, contingency, alternate, final reserve and extra. Use the PLOG: leg time, fuel flow, wind component. The triangle of velocities gives heading and groundspeed. Chart traps include units (lb versus kg, US gallons versus litres) and interpolating between grid lines instead of reading the nearest printed value.
Worked example
Runway 27, wind 300 degrees at 20 kt, so the angle is 30 degrees. Crosswind = 20 × sin 30 = 10 kt; headwind = 20 × cos 30 = 17 kt. Rule of thumb: at 30 degrees the crosswind is half the wind speed; at 60 degrees it is about 87 percent.