Flight Performance
Performance fundamentals
RPA performance depends on mass, air density, power available and the flight profile. Candidates must understand how altitude, temperature and humidity reduce air density and therefore reduce rotor thrust for a given power setting. Know the concepts of hover ceiling, service ceiling, rate of climb, maximum endurance and maximum range, and understand that endurance and range are optimised at different speeds.
Concepts to master
Learn the effect of wind on ground speed, endurance and the energy needed to return to the launch point. Understand that a headwind outbound and a tailwind inbound do not cancel out in terms of energy: the penalty is always greater than the benefit. Know how payload mass affects climb performance and battery consumption, and how aggressive manoeuvres increase current draw. Understand the relationship between battery capacity, usable capacity and the reserve that must be kept.
Common traps
Questions often present a wind that appears to cancel and expect the candidate to recognise that total energy is higher. Another trap is assuming performance scales linearly with battery capacity. Watch for density altitude problems disguised as simple altitude questions.
Rule of thumb
Plan with a reserve of at least the energy needed to reach a safe landing area plus a margin, and never plan to land with an empty battery. Worked example: with 20 minutes of hover endurance in still air, a 10-minute outbound leg into a headwind and a 10-minute return with the same wind as a tailwind will exceed 20 minutes total, because the outbound leg takes longer than the return saves.