• PiperForum.com is a vibrant community of Piper owners and pilots. Our over 1,500+ active members use Piper Forum to swap technical knowledge, plan meetups and sell planes/parts. We host technical knowledge of general aviation topics and specific topics on J3-Cubs, Cherokees, Comanches, Pacers and more. In addition to an instant community of pilots for you, PiperForum.com is a library of technical topics, airplane builds, images, technical manuals, technical documents and more.

    Access to PiperForum.com is subscription based. Subscriptions are only $49.99/year or $6.99/month to gain access to this great community and unmatched library of Piper knowledge.

    Click Here to Become a Subscribing Member and Access PiperForum.com in Full!

Propeller TBO - Hours vs Age

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


Well-Known Member
Dec 29, 2010
Reaction score
I have posed the following question to my IA, but I thought I would solicit feedback from those of you who may have been down this road before:

My 1968 Cherokee "D" has a fixed pitch McCauley prop: Model BMS 7660, Blade No. 1A170. According to McCauley’s latest Service Bulletin http://www.tiffinaire.com/Files/TBO McCauley sb137ae.pdf, the TBO for that prop is 2000 hours or 72 months, whichever occurs first.

The SB also states: “All deviations from published TBOs must be approved by your local Regulatory Authority with a recommendation from McCauley."

The prop was last overhauled in September 2005, so I am 3 months past the 72 month limit. (The prop only has about 530 hours on it.)

Ordinarily, I wouldn’t worry about going past 72 months and would just plan to overhaul the prop at 2000 hours, but the Service Bulletin language quoted above seems both unequivocal and mandatory. In your opinion, does the Service Bulletin language affect the current airworthiness of the aircraft?

Latest posts