I understand that helicopters have varible pitch blades. Are there any fixed wing aircraft with variable props

Answer 1

There seems to be a bit of confusion on the part of those answering. There is a difference between variable speed props (not many of those left) and constant speed props which most of our more complex aircraft have these days. The only variable speed I've ever flown was an old Bonanza back in the late 70s. Had a toggle switch that varied the blade angle, but was NOT constant speed. Climb and the engine slowed down, dive and it sped up. With a constant speed prop, the rpm stays where you set it, regardless of attitude.

Answer 2

helicopters utilize changing the angle of pitch( or angle of attack, proper) to the blades of both main, and tail rotors to control their flight . The main rotor is capable of doing this in 2 ways. it can vary the amount of pitch in both cyclic and collective configurations.In the collective control, the pitch adjustment is constant throughout the full 360 path of the blade. This control Is for up/ down movement. The range of this flight control varies from flat, or 0 degree of pitch to a high angle , used for max lift...........The cyclic control can also vary pitch angle, but it`s effect is to `tilt` the rotor{ imagine the swinging rotor is a disk} thus effecting pitch & roll control, as the rotor tends to lift in a direction perpendicular to blade travel, [ie. if you `tilt` the rotor `disk` to the right, {blades lower on the right, higher on the left} the rotor will apply a rolling force to the right. Tilt back, and the aircraft will nose up, and so on. And there is more........ the powerplant of the helicopter is generating a force on the main rotor and air resistance in turn generates another force, or torque in the opposite direction of blade travel. Without some counter- force, the engine would spin the aircraft in circles, and it would get worse as you increased power, the thing would not fly, and it`s occupants would be too dizzy to enjoy the ride.... the tail rotor is yet another vari- pitch prop, it is a cyclic control, varying pitch at a constant angle throughout 360 of rotation, similiar to the main cyclic. It keeps the helicopter in a straight path.......it is interesting to note, that it takes almost full power to hover a helicopter just above the ground, while staying motionless. Can u guess why?......almost all aircraft that use propellers are variable pitch, this technology has been around since before WWII, todays versions can even achieve high negative angles and BAM, now your propeller can help bring you to a full stop after a hairy landing.pretty cool, huh?

Answer 3

Yes, typically aircraft with 180 or more horsepower.

Not all constant speed props are capable of feathering. A cessna 172RG prop only moves about 7 degrees total.

SA Writer is wrong, ignore this response.

BitburgerPilsMan is half correct. This answer applies to direct drive engines only and then only at flight power settings. The engine does not run at 100% when taxiiing...

aftabmajoka...this post makes no sense

Wildcat 747...listen up...
A constant speed prop keeps the blade angle adjusted for maximum efficiency for most conditions.
During takeoff when maximum power and thrust are needed the prop is at a low blade angle or pitch. Small bite of air it taken. This small bite allows the engine to turn at a high RPM to generate is maximum horsepower. So for max power and thrust the prop pitch is set to a pitch that will give the max possible blade angle (bite) that will also allow the engine to develop max RPM. Although the mass of air handled per revolution is small, the number of revolutions per minute are many. The result is high slipstream velocity+low airplane speed=max available thrust.

At cruising altitude in level flight where less power is required than is used for takeoff or climb engine power is reduced with throttle. The prop lever is used to increase the blade angle (bigger bite) to slow engine RPM. Fewer RPM equates to lower fuel burn. Although the mass of air handled per revolution is greater it is more than offset by a decrease in slipstream velocity and an increase in airspeed.

The fuel to air ratio is controlled with the mixture lever.

Answer 4

I've flown both a bunch and it depends which helicopter and which fixed wing we're talking about. Anybody who's flown a Pitts into Santa Paula, CA will tell you that getting that airplane into that airport is one of the hardest flying tasks anywhere. If the helicopter is say an S76, my eighty year old mother could probably fly it with the stability augmentation on. Tail wheel airplanes like the Pitts are a ground loop waiting to happen. You don't stop flying the suckers until the chocks are in place and the tie downs fastened.

Answer 5

On just about every turbo-prop, the engine runs at full throttle, just about 100%, and the speed of the aircraft is controlled by the prop blade angle.

Answer 6

In fixed wing aircrafts where prop assembly is used,it normally assist with CSU (constant speed unit).This CSU changes the pitch of prop from coarse to fine and fron fine to coarse.This is done by feathering,the action of prop blade to tilt in its own horizental action.got it or not,and every aircraft with prop assembly got this mechanism

Answer 7

Yes. Virtually all propeller driven aircraft have variable pitch blades. You may have heard of pilots "feathering" their props. This is varying the pitch so the prop does not provide thrust while starting the engine.

Answer 8

Yes to both when taking off a plane needs all the Bite it can take out of the air to get off the ground, once in flight you ease off the throttle and blade pitch and lower RPM to maintain air speed at the best air to fuel ratio, plus the pitch of the blade. some of the older air craft that developed 3000 horse power could not at first but I may have that wrong they developed it later on to help get the planes off the ground much faster,, look at a crop duster and it is a powerful machine that has variable pitch and a whole lot of horse power to pull it straight up into the air, On the other hand the pitch of the blade on the copter gives it it's forward momentum, along now with a jet thrust. but it to allows it to hover in one place by adjusting the pitch of the blade.

Answer 9

Yes, in fact most of the high performance prop airplanes have variable pitch props.

Answer 10

I know that the old multi engine bombers from WW2 had variable pitch props because when one engine went out they would "feather" the prop to decrease the drag from the stationary prop.