Mission 4
The Power Problem
Speed costs power — and so does going slowly.
Difficulty
Briefing
An inspection run: fly out to the far marker and back on a partly used battery. The autopilot flies the route; YOU choose the cruise speed. Too slow and you spend too long in the air; too fast and drag eats the battery. Land with at least 15% left.
Objectives
- Choose a cruise speed
- Complete the out-and-back route
- Land with at least 15% battery
Physics in play
Power required vs airspeedEnergy = power × timeRange = energy ÷ energy per metre
Hampton’s .02 cents
a multirotor uses LESS power flying at a moderate speed than hovering — moving air through the rotors helps them (translational lift). Past that sweet spot, drag grows with speed squared and power with speed cubed.
Instructor insight
It would behoove you to look at the power curve in the Wing vs Rotor lab before you choose. The cheapest speed per metre is not the cheapest speed per second.