2007-11-08 09:27:04 · 10 answers · asked by lazaro_garzanieto 2 in Politics & Government ➔ Military
The rotor blades cause the air pressure above the chopper to be less than the air pressure below it, causing the copter to lift.
2007-11-08 09:56:46 · answer #1 · answered by Anonymous · 0⤊ 2⤋
6.5 x 284 is dead on. Each blade is an aerofoil or wing. As the center rotor/main rotor spins the aerodynamic effect of each blade causes an area of low pressure to build up above it and an area of high pressure to build up below it. The "bite" each blade puts on the air, as well as the speed of rotation creates enough lift to raise the helocopter off of the ground. The main rotor can be tilted fore, aft, left and right to allow for forward, rearward, and left/right movement. The tail rotor increases or decreases in speed to allow the helo to turn one way or the other. The torque the main rotor puts on the airframe always wants to force it in the opposite direction so the tail rotor counters that force.
On a side note...have you ever wondered why helocopters make that whoop whoop whoop sound when they fly? It usually occurs during forward movement of the aircraft. Imagine that you are looking down at a helocopter from above the main rotor. The nose is at the 12 and the tail is at the 6 position. The blades spin pretty fast, but there is a point during flight where the speed of/air pressure on each rotor blade tip drops below the sound barrier. This is over simplified but if you can imagine that the blades are spinning clockwise. (No yelling...I know.) Once forward movement begins the area of lowest pressure on the blades will be the point where they are moving away from the air pressing forward on the airframe as it flys. So from 12 to 6. As the blade continues its spin past 6, the pressure increases because it is working against the forward movement of the airframe and the air. So from 6 to 12. At the 12 to 6 point, the rotor tips are spinning at a lower atmospheric pressure than they are from 6 to 12. Get it? Ok. The pressure difference causes little sonic booms to occure at the point of increased pressure. (i.e. the 6 position) Thus you get the whoop whoop whoop sound so commonly heard. They are sonic booms, only smaller.
Ain't science grand?
2007-11-08 18:47:40 · answer #2 · answered by theGODwatcher_ 3 · 1⤊ 0⤋
its called "a balance of oposing forces"...the tendency of the rotor to torque the aircraft is countered by the tail rotor...the rudder pedals affect the tail rotor to allow the pilot to use the torque to orient the aircraft without spinng out of control...the pilot uses the throttle to control the engine speed,the pitch of the blades(the bite) is also controled by the same stick the throttle is located on,the cyclic stick to change direction of the rotor cone,allowing the aircraft to move forward or other direction and the rudder pedals to turn..all these must be balanced before proper flight can be achieved
2007-11-08 18:05:12 · answer #3 · answered by Anonymous · 1⤊ 0⤋
Just barely. Pilots like to say that the machines don't want to fly and you basically have to fight to keep everything in balance or they'll head straight to the they only place they really want to be - the ground.
2007-11-08 18:27:46 · answer #4 · answered by gunplumber_462 7 · 1⤊ 0⤋
Helicopters are exempt from the law of gravity. Kind of like diplomatic immunity but in the air.
2007-11-08 17:39:59 · answer #5 · answered by t. B 5 · 2⤊ 2⤋
It is all done with strings and mirrors.
Retired USAF B52 Pilot
2007-11-08 17:33:42 · answer #6 · answered by ? 6 · 0⤊ 1⤋
By beating the air into submission.
2007-11-08 17:31:40 · answer #7 · answered by Groucho 4 · 4⤊ 1⤋
Very carefully!
2007-11-08 18:20:16 · answer #8 · answered by Bubba 6 · 1⤊ 0⤋
the propellers pull the air down from above and push it down. that's a simple explination
2007-11-08 17:42:28 · answer #9 · answered by kt201 1 · 1⤊ 2⤋
same way planes do, it's just that the wings are above, and moving.
2007-11-08 17:38:28 · answer #10 · answered by Anonymous · 1⤊ 1⤋