How do I get more thrust?

[Circa]

I push forward on the cyclic but I can only get like 30mph/kph/knots I've messed with "trimmer" but it just changes the pitch at which i start gaining altitude not useful for going forward. Can you pitch the engines towards the rear or something?

 

thanks!

[Majesco]

Increase throttle with "PageUp" and "PageDn" for reducing (3 or 4 levels)

[bradmick]

If you pick the aircraft up to a hover, and leave the collective at that point, you're only going to go so fast for a given pitch setting before you start to descend. As you increase airspeed, collective pitch is ultimately going to be reduced because the rotor system is becoming more efficient. That being said, a helicopter is not like a jet, the turbine engines do not provide the thrust like in a jet, pitch is you're primary means of gaining forward airspeed, but you have to have a given power/collective setting to maintain that airspeed, without it you start to descend.

 

Brad

[ruprecht]

Forget everything you know about fixed wing. Think about it like this.

 

The rotor disc is the thing that flies - the fuselage is just along for the ride. The collective (commonly called throttle, but this is incorrect) increases the pitch of the rotor blades the whole way around the disc (collectively) creating more lift. When lift equals gravity in the hover, the helo hovers. When lift exceeds gravity in the hover (by pulling more collective), the helo goes up.

 

All the engines do is keep the rotor(s) spinning. They don't provide thrust or lift.

 

When you move the cyclic (the "stick") you are increasing the blade pitch at one side of the disc, which causes the disc to tilt, which tilts the lift vector. You have the same amount of lift, but it is now tilted off the vertical so there is a small horizontal component of lift (or thrust). Hence the disc starts moving horizontally. However, as the lift vector is tilted, there is now slightly less vertical component of lift, so the helo sinks.

 

The more you push the cyclic, the more the lift vector tilts, and the more horizontal component of lift (thrust) you get. However, you also get less and less vertical component of lift and you sink more. If you tilted the disc right through 90 degrees - you'd get all "thrust" and no "lift".

 

So to offset that, you pull in more collective to extend the lift vector to the point where the vertical component of lift balances gravity and you maintain height. Past a certain tilt angle, the disc can't provide enough lift to extend the lift vector enough to offset gravity. This is one thing that limits the forward velocity of a helo.

 

There are of course a hundred other aerodynamic effects playing on the helo, but that is the core theory.

 

Easy huh? :)

Edited January 15, 2009 by ruprecht