17 ms·

Sounds like a helicopter is not very efficient?

• AnotherGoodName 8mo ago
  Less efficient than an aircrafts wings over a long distance but very efficient for an aircraft with engines pointing straight down. The blades are massive, push a lot of air relatively slowing compared to smaller engines. There's a reason most planes will stall when pointing straight up, despite in theory having more power to weight. Their prop efficiency is worse than a helicopters rotors.
• kingstnap 7mo ago
  Not for moving sideways at a constant altitude. If you think about what a plane does to keep itself up, it sweeps through a curtain of air which ends up blowing downwards. In a second it must blow down a large volume of air with enough speed to equal the impulse created by gravity in a second. Basically m_air × v_down = m_plane × gravity × time The energy you need to do this is the same quadratic, 1/2 m_air × v_down^2 A larger volume of air with a smaller v_down (a huge curtain of air of a fast plane with very wide wings) is more efficient then the smaller disk of air with high velocity of a helicopter. But if the plane isn't moving forward the curtain has no volume and the plane stalls and falls. But helicopters have no trouble lifting off vertically.