The International Cessna 170 Association

I'm having a brain failure. Did I promise you McCauley prop data at one time?

I promised someone I'd fax that info...and I did but they didn't receive it. They then

asked me to send it along with some parts I was shipping.... and at the time I could not

locate my prop overhaul manuals. Now I found the manuals and cannot recall

who it was I owed the data .



Thanks

George Horn

Parts/MX TIC170A

Looks like CRS is kicking in.

I would tell y'all what CRS is, but I can't remember.

Tom Rush on CRS -

http://www.youtube.com/watch?v=9yN-6PbqAPM

George,

Would you mind sending me the McCauley propeller o/h data you? Do you have a manual? What are the requirements to have a fixed pitch prop o/h'd, hrs, condition...?

Thanks!

http://www.aeropropeller.com/PDF/McCauleySB137AA.pdf
Does this sound familiar to anyone?
Item P. in the link above on page 12 says: Fixed pitch propellers - 2000 hours or 72 calendar months which ever occurs first.

So basically every 6 years the prop needs an OH???

Does anyone else have any info regarding prop OH and the link I posted? Thx

Yes, I have the McCauley manual and I will scan and post the information relative to most of our propellers and place it in the MX Library.

McCauley Service Bulletin 137U specifies the overhaul times for propellers and all fixed pitch propellers in ordinary service (not agricultural or aerobatic) is 2,000 hours or 72 months. Additionally, the mounting bolts torque must be checked annually, and replaced whenever a prop strike is experienced. The bolts must be magnetic and/or dye inspected or replaced at every overhaul. That's all according to McCauley, of course.

It has been my experience that many prop shops will aggressively grind/sand/buff any propeller submitted for overhaul, to remove all nicks, scratches, signs of service, to get the metal down to base metal. THEN they will measure for acceptable wear and dimensions. Of course, such aggressive techniques condemn many otherwise serviceable props and the owner then must purchase a replacement from them or their competitors. There is a prop shop in SAT (with a name similar to a retired NBAA basketball star) that I particularly avoid due to my personal observations of their work.

My own recommendations to operators is that anytime the prop is removed for any reason, to clean and inspect it under 10X magnifying glass for cracks, especially at the tips and hub and mounting holes, as well as for corrosion at the hub face where it mates with the crankshaft. A dye penetrant inspection is a good idea. Also measure the hub mount holes for dimensions and distance from outer hub walls, blade for length, thickness, chord, and confirm pitch on a flat table, using the ovhl manual specs. The prop should be alodined and painted before reinstallation.

I would not anticipate most operators to perform such an inspection except when other major engine work or repair is accomplished. My own prop was overhauled about 12 years ago, has not been removed since, and has about 800 hours on it. I do not intend to overhaul it again, but if I have occasion to remove it I will perform the inspections mentioned.

Except for the hub, my prop is polished. I bought the airplane that way. I would alodine and paint it if I ever removed it, and would not polish it again.

gahorn wrote

Except for the hub, my prop is polished. I bought the airplane that way. I would alodine and paint it if I ever removed it, and would not polish it again.

I assume its not polished on the back side?

My prop is polished on the front side and I have had the same thought. When it ever comes off, have it painted. I also wonder if a prop shop would let it go unpainted.

Why would you have it painted? Maintenance issue or looks?

Bill

The face is painted black to avoid glare to the cockpit, but the camber is polished. I'd paint it for corrosion control. Every time you re-polish the prop removes metal, and unless you keep it polished it will corrode.

Isn't it true that not all props can legally be polished? (I can't remember how to find out if a particular prop can be polished, but I'm sure a prop shop could advise me).

That's a trick-question. If you follow the overhaul procedures in most mfr's manuals there is usually no procedure that leaves the prop in the polished condition, but instead treats it with Polane or some other paint as a protective surface. Therefore there are those who will say that anything else is "unapproved" or "illegal".

I don't buy that. There is a story that circulated for a while that the FAA had some inspectors who were placing "condition" tags on aircraft with polished props.... until someone pointed out that the FAA's own DC-3 had polished props.

The controversy seemed to take a back-seat after that.

(There are also those who claim that "polished" simply means "cleaned" as in "cleaned for inspection". I don't really know. Mines been polished and passed annual inspections from a half-dozen different inspectors and been seen by several FAA inspectors and no one has made note of it either way.)