Prop Mounting Question

[farmrjohn]

I've removed the McCauley DCM propeller from my O-200 powered Alon for the annual inspection. Upon removal I noticed that there were thin AN-960 washers on both sides of the front plate. Looking at the Erco, Forney, and Alon parts manuals there is not a depiction of any washers. The Mooney M10 manual does show a single AN-960 washer (standard thickness?) between each bolt head and the front plate. Which is correct? Ercoupe part number Mooney Part Number

 

[Clip4]

Maybe ask MCCauley, but a washer between the bolt head and the front plate seems proper.

 

[Bell206]

Looking at the Erco, Forney, and Alon parts manuals there is not a depiction of any washers

FYI: the O200 wasnt a standard engine on the Alon. I dont recall if there was a bulletin to install one or if they were all done via field approval or STC. That documentation is where it would list or call out for washers. Perhaps research how your 200 was installed and check those docs. Or call Univair as they hold all the TCs for that group of aircraft and still provide some tech support for those models.

 

[farmrjohn]

FYI: the O200 wasnt a standard engine on the Alon. I dont recall if there was a bulletin to install one or if they were all done via field approval or STC. That documentation is where it would list or call out for washers. Perhaps research how your 200 was installed and check those docs. Or call Univair as they hold all the TCs for that group of aircraft and still provide some tech support for those models.

Correct. The Alons came with the C-90 engine. Mine has an O-200 thanks to Chevron's Jet-A fuel mix up in Watsonville back in the 90s. The installation was via a 337 field approval based on the STC which at that time was limited to the D model Ercoupe. The paperwork specifies the propeller but not any actual installation details. Answers to my tech questions to Univair have been less than stellar. Apparently their subject matter expert on all things Ercoupe/Aircoupe/Cadet has retired. That's why I'm asking here. It's my understanding that the other little Continental C series engines have the same crank flange so the mounting should be the same. Hopefully there is information on what other O-200 applications call for, assuming the front plates would be similar.

 

[Magman]

It sounds like an attempt to shim the front plate to align with

the Spinner. Maybe one of those w/o pre- drilled holes?

 

[Bell206]

The installation was via a 337 field approval based on the STC which at that time was limited to the D model Ercoupe.

Have you tried contacting the STC holder for input?

Apparently their subject matter expert on all things Ercoupe/Aircoupe/Cadet has retired.

Good to know. So had their main parts guy a while back. Tough people to replace.