Service Ceiling for a C85 powered 415-C?

Larry,

Good catch! The prop hub is definitely marked 73/49 so I will have my A&P look at it. I know I'm meeting the static RPM, the prop was overhauled once (maybe shortened? Definitely was repitched) and I remember someone telling me that there's a trick to measuring the length of rounded tip propellers.

Will report back with findings.

Brooks, if you have a 73 inch propeller on your airplane with a C85 you are illegal! Read the rather convoluted information in TCDS 718. The legal lengths of a McCauley on a C85 range from 69.5 to 71 inches. The 73 was for the C75 only. I believe if you go to a 71 you will see a marked increase in power.

I've been curious for a long time. Since I'm a sport pilot, I'm not allowed above 10,000, except to avoid terrain... and there's nothing tall enough on the east coast to qualify.

I have flown to 9900 (C85 "stroker" with a McCauley 1A90 73/49.) At that point I was still climbing at 250-300 FPM - solo with slightly more than half fuel. It was an interesting flight since it was 97 degrees on the ground, and as I climbed it became more comfortable to close the windows and then to crack open the heater. On the way down, experiencing the return to 97 degree heat was a lot less fun.

Sweet, good memories, sounds like a great trip!

I was stopping in Cut Bank to visit friends. So, from Seattle we followed i-90 to Missoula, then angled towards Lincoln MT following MT200 and crossed the divide at Rogers Pass. Then headed North. We ran out of light and spent the night in the pilots lounge at Choteau (really nice pilot lounge with fresh fruit, drinks, and snacks and a loner car), then continued to Cut Bank the next morning. That was my favorite leg of the entire trip, flying over flat farm land with the rugged continental divide, Bob Marshall Wilderness, and Glacier Park, just a few miles off the wing tip.

Understood on the altitude and loadout. And with a DA of +2000 to boot that is good to know! Looks like we have the same prop. Looks like it was a gorgeous flight! Did you fly over Helena or down to I-90 then over?