Flight Performance and Planning
Performance categories
Helicopter performance is normally presented in categories (for example Category A and B) defined by the ability to continue or reject safely after an engine failure. Category A guarantees continued flight after failure at the critical decision point; Category B permits a forced landing. Know the definitions of take-off decision point (TDP), landing decision point (LDP), defined limiting point, and safe forced landing.
Charts and traps
Performance charts are entered with pressure altitude, temperature, weight, and wind. Traps include using indicated instead of density altitude, forgetting to apply the wind correction in the correct direction, and mixing gross and net performance. Also be ready for HIGE/HOGE (in-ground-effect versus out-of-ground-effect) hover ceilings - a frequent distractor swaps the two labels.
Weight and balance
Compute moments about the datum, remember that fuel density varies, and check the longitudinal and lateral CG envelope separately. Aft CG reduces forward cyclic authority; a question may ask which limit is approached first when loading baggage.
Worked example
Pressure altitude 4,000 ft, OAT +20 °C, mass 2,200 kg. Enter the HOGE chart at 4,000 ft, move to the temperature line, read the maximum mass; if it is below 2,200 kg, the hover is not achievable. Rule of thumb: always convert to density altitude first, then read mass - never interpolate between altitude and mass without fixing temperature.