How does a helicopter go down?

Question

do they have to make change the direction of that big fan blade to provide reverse lift?

Answer 1

By their is a lever that controls the throttle and go by the feeling of the helicopter starting to go down.

Don't forget to vote best answer.

Answer 2

the rotar speed is slowed down so that the force that the rotors provide (upthrust) is less than the force of gravity so that it goes down

Answer 3

How does a helicopter go down?

Like the rest of us I suppose....with a hand pushing the back of its head....

Answer 4

SWITCH THE ENGINE OFF.....

Answer 5

Airplanes, gliders, baloons, helecopters, birds, you name it; they all go down for one reason and one reason only. Gravity. Jeez people c'mon.

Answer 6

http://en.wikipedia.org/wiki/Helicopter

Answer 7

Smudge is right in a way. If you slow the rotor enough, you will be going down, quite violently in fact. But that's not how a pilot will descend a helicopter. If you want to descend in a controlled manner, you will decrease the collective pitch angle of all rotor blades, and thus reduce lift, as iccaris indicated. You can't change the spinning direction of the blades, nor can you produce "reverse lift". It's just a matter of reducing lift enough so that gravity accelerates you downward.

Hey Snorky, shoot me an e-mail sometime ; )

(Added)

You do NOT change the rotor RPM during normal cruise flight unless you want to exceed the limitations of the aircraft and create a potentially unsafe condition, although you would descend, like a rock you might say. Helicopters operate at a basically constant RPM during flight, whether climbing, descending, or hovering.

Answer 8

No. The "big fan thing" is called a rotor. The individual blades of the rotor tilt. This is called "pitch". The more pitch the blades have, the more "lift" they generate. The less "pitch", the less lift. The blade pitch is controled by the pilot with a control stick called a "collective".

Answer 9

They can change the angle of the blades, meaning they can move the angle the blade meets the wind, which changes rotor rpm and lift. Like twisting your hand as you stick it out of a moving car.

They can also pitch the helicopter downwards while moving forward, because in that case, it acts more like a fixed-wing aircraft and goes down.

They can also simply drop straight down by reducing rotor rpm.