Originally posted by Jekyll:
Hell, does ANYONE really use EZ Takeoff other than in the TA?
[This message has been edited by Jekyll (edited 01-01-2001).]
Jekyll,
Usage of constant speed prop is not how you imagined it.
You set the desired RPM of the prop / engine by using the propeller control. Once the RPM is set the prop will maintain that rpm as you manipulate the throttle. More power to the prop means the prop will coarsen the pitch to maintain the preset RPM. If you lower power (throttle) the prop will fine pitch to it's built in limit at which point the rpms will drop as the engine is not putting out enough horses to maintain the RPMs. If you coarsen the pitch sufficiently the engine will bog down and lose RPM's. In my Comanche it is possible to coarsen the pitch enough in the preflight checks to kill the engine.
Prop control is maintained in two ways. Either by an electric hub or a hydraulic hub. The electric was an early version and was extensively used in WW2 bombers. That is the prop that could "run away" (go to ultra fine pitch) and destroy the engine if it couldn't be shut down fast enough. It also required the plane have a functioning generator to maintain enough electrical power to operate the prop. The battery will not hold for very long.
The hydraulic hub uses engine oil under pressure through the crankshaft or a separate line that maintains pitch by using the set pressure from the oil. A valve either opens or restricts oil flow / pressure to change blade angle. When the engine stops, the blades revert to the setting intended by design and the restraining springs in the hub. In small single airplanes it is usually fine pitch. In a multi engine plane it may feather to reduce the drag in case of an inflight engine failure.
Power is a function of the engine and how much throttle you are using. The constant speed prop regulates the RPMs as opposed to a fixed prop plane where the only control you have is the throttle.
If you change the pitch only, the engine RPMs will fluctuate unless the throttle is moved in a coordinated manner with the prop pitch control. This is because the load on the engine changes with the pitch.
Constant speed props mean you can fine tune the performance of your plane to best use the horsepower from the engine and get best efficiency from the plane. You can have a "climb prop" when climbing and a "cruise prop" when cruising which is not possible in a fixed prop plane.
Finally in answer to your last question, yes I use easy take off in MA. I see no reason not to at this time. If I need to abandon the runway on takeoff all I have to do is move my stick. I do try to avoid capped fields and the attendant vulchers however.
I hope this helps you to understand that the constant speed prop is not effective in controlling or manipulating torque.
Mav