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View Full Version : Question about "manual" control of CSP props.



lbhskier37
07-07-2005, 08:37 PM
It has been brought up in another thread that allied aircraft with CSP props had a manual backup that could be used to directly control prop blade angle like a normal variable pitch prop. Does anyone have specific info on this, how the system worked, what aircraft this feature was on. If this feature really existed than it would be nice to get it. I struggle to understand how this system would be implimented, and why. In a CSP prop as I understand it the pilot directly controls a governor that controls oil pressure going into the prop hub depending on rpm. This oil pressure is what varys the blade angle. Now wouldnt a direct manual control have to use hydaulics too? If so, how would this system be much of a back-up, ie loss of hydraulic fluid in the prop would still cause it to run away to full fine pitch. Skychimp you still around? Or anyone with some good info?

JG52_Meyer
07-07-2005, 09:52 PM
They didn't have it.

bolillo_loco
07-07-2005, 11:48 PM
its quite simple. The P-38 for example. the pilot flicked a switch that turned off the CSP and put it into manual over ride. the pilot could then increase and decrease prop pitch however he felt.

I am going to give a link to a video that I have and I have also heard several people talk about having it as well. they can either confirm or dispute my statement by watching Jeff Ethell do the pre take off check where he runs up the engines, tests the CSP by increasing and decreasing rpm, then turns off the CSP and using manual pitch to increase and decrease rpm, then switches the unit back into automatic, and checks his mags.

why is it so hard to believe that american aircraft had manual pitch control? what do you think they did when the curtis electric or hamilton standard CSP unit failed? american aircraft had redundant back ups for many things.

BTW, the video is only 5 dollars and change.

P/S when I first read your post I could see your signature pic, but after I responded it disappeared.

http://www.amazon.com/exec/obidos/tg/detail/-/B00000FBP...41422?v=glance&s=dvd (http://www.amazon.com/exec/obidos/tg/detail/-/B00000FBP0/qid=1120801480/sr=1-1/ref=sr_1_1/103-2502154-9241422?v=glance&s=dvd)

lbhskier37
07-08-2005, 05:47 AM
This is just the first time I have ever heard of this, I've never even heard it mentioned on here before. I don't really find it that hard to believe, I want to understand the mechanics of the system because as I understand a CSP it seems like it would be hard to impliment. Is there any reference to using it in the pilots manual? Do you use this system if your props start running away on takeoff?

bolillo_loco
07-08-2005, 02:26 PM
Originally posted by lbhskier37:
This is just the first time I have ever heard of this, I've never even heard it mentioned on here before. I don't really find it that hard to believe, I want to understand the mechanics of the system because as I understand a CSP it seems like it would be hard to impliment. Is there any reference to using it in the pilots manual? Do you use this system if your props start running away on takeoff?


why does it sound so difficult to impliment? if i remember correctly you have no trouble accepting the fact that german aircraft had a constant speed prop and also had manual pitch control. I care not to split hairs here I have seen people call the CSP the germans used a different name. it was still a unit that maintained a certain rpm setting automatically even though you could increase and decrease engine power, whith in limitations of the unit.

I would suggest getting the video at 5 dollars it is very cheap. I wish they had videos like this on every WWII aircraft that were only 5 dollars each..........I would collect them all. the video only shows how to use manual and CSP, it doesnt explain how they work mechanically.