The International Cessna^® 170 Association

I have a CESSNA models 172 & 175 Illustrated parts catalog for 1956 - 1962 models. (Basically the same as the 170B catalog I also have). There are quite a number of "parts" shown as being available on these aircraft such as the stretcher option, which I suspect were never used on 170-175 models except in very rare instances. One interesting item shown under the C-175 items is a McCauley Constant Speed Propeller. I don't know much about C-175 airplanes, but don't believe I have ever seen one with a CS prop. Just wondering if others are familiar with this option and also wondering if it could be added to a Continental GO-300, why couldn't it have been added to a Continental O-300? Just curious

170C wrote:I don't know much about C-175 airplanes, but don't believe I have ever seen one with a CS prop. Just wondering if others are familiar with this option and also wondering if it could be added to a Continental GO-300, why couldn't it have been added to a Continental O-300? Just curious

I'm not sure but I think the reason why is the GO-300 engine turns in the opposite direction than the O-300. The GO has a reduction gear box so I think the props would turn about the same RPM and in the same direction. Hope someone who knows will answer.

It is my understanding that only certain late models of the GO-300 engine were set up for a governor and a CS prop. It finally died from lack of popularity.

There was a two position prop available for , I think the C-145 that had a lever on the front right hand side that controlled the prop. I believe it was a McCauley prop and was very heavy. I have only seen one and that was on a plane that attended one of the Kentucky Damn fly-in years ago. I don't recall who the owner was.

Ed Booth, Trenton, SC

Dave Bengtson & wife Ruth of Van Alstyne, TX have a '56 170B (really nice one) that has the two position McCauley. Only one I have personally seen. Its on the Continental O-300B engine (same as on Ole Pokey). Lever is on the left on these engines. They have been to multiple fly ins and conventions with the bird. Apparently it is pretty heavy, but does help with takeoff, climb and may help some with cruise. I believe George and maybe Bruce have flown in it with Dave.

The 175-C had the option of the GO-300-E engine which accepted a Garwin prop governor and McCauley C-20 Constant speed prop. My friend had one and I think I told that story somewhere here on the forums.

The bottom line is that it added weight and complexity to an already too-complicated airplane that did little more than a standard 172 would do (at the cost of a 182 but without 182 performance.) It cruised at 110 knots and burned 11 gph of fuel, and had a 1200 hour TBO...but never got that far in most cases.

The C-20 prop is rare and has an expensive AD note on it.... the prop blades are threaded into a ferrule which is held by the hub, and the threads must be "truncated" according to the AD. There is only ONE repair station in the WORLD who will do that work...they are in Germany. The repair costs about $8-Grand to perform. Plus shipping. Plus Customs. Plus hub-recertify. Plus labor.
The last two blades are/were in a Seattle prop-shop and they want $8-Grand APIECE for them....which is about what a C-175 is worth if it's CS prop is unairworthy due to an unaccomplished AD. Most owners willing to spend money put a Lycoming O-360 in the airplane so it can perform similar to a 170 with the same engine. (Might be an easier way to get 175 wings approved, however.)