Performance
Performance questions require you to select the correct limiting factor for the phase of flight and apply the right chart or formula. Understand take-off distance (ground roll plus airborne distance to 35 ft), take-off run, and the balanced field concept. Know the effect of density altitude, wind, slope and runway surface on distances, and the meaning of V1, VR and V2.
For landing, understand landing distance from 50 ft, the effect of reverse thrust and braking action, and the requirement for a factored landing distance. Climb performance questions test the difference between best rate (VY) and best angle (VX) of climb, and the effect of mass, altitude and temperature.
Traps: applying a headwind component to the airborne segment as well as the ground roll; forgetting to correct for pressure altitude versus density altitude; and using the wrong chart axis.
Worked rule of thumb: density altitude increases approximately 120 ft per 1°C above ISA at a given pressure altitude. For a rough take-off distance change, a 10% increase in density altitude can add roughly 10% to the ground roll; always read the chart rather than extrapolating.
For climb, remember that VX increases with altitude and VY decreases, and they converge at the absolute ceiling.