Composite Prop TBO-just ignore it?

Looking at a 13 years old Cirrus, TBO on the prop is 6 years. Every piece of literature I can find says this is critical to maintain the prop, seals, etc. Of course the broker says it’s a waste of (his clients) money to follow the TBO on props and no one does it.

Any opinions appreciated.

I have always IRAN the prop and associated components. Not that I have a long history of plane ownership.


This has been discussed extensively.

Please review at this link

That link appears to contain only a single reference to a YouTube video. I’d like to hear more opinions on this as well as I’m in the same position as the OP.


You posted on the guest forum. If you are a member, I can link you to a thread I started in 2014 to discuss this question in detail regarding a 2008 composite prop. There are knee-jerk answers, and then there are well-researched answers specific to the Hartzell composite prop, etc.

And, for what it’s worth, some of us do have them overhauled, and for good reasons.

A Forum search using the keywords “prop and reseal” yields this big list of relevant threads.

That’s a useful list, but is going to become a lonely place if we discourage people from asking questions about topics that were addressed previously, sometimes several years ago. People are always free to ignore questions they believe have been addressed fully.

I have a 4 blade MT prop; The blades have unlimited life;

The prop book lists a 2800hr TBO;I looked up the SB, its now 2400hr 72mo on condition.

I just IRAN’d my 4 blade MT prop. I had significant paint erosion on the leading edges due to a bad MT white paint spec 10 years ago when the prop was manufactured. I decided to send it in to get it repainted. I sent my prop to South Coast Propeller in Alabama. When they disassembled the prop they noticed the blade seals were slightly leaking. This prop had about 800 TSN. I had them replace the blade seals.
When I had spoken with MT in Deland, FL a year prior they told me they obviously had to put a TBO out there for commercial operators, but for Part 91 their advice was if you don’t see grease leaking you can keep flying it without worry.
The only difference between what I did and an overhaul was that I did not have the paint stripped off the hub and have the hub NDI’d and repainted prior to having the prop re-assembled.
If you don’t feel comfortable with “fly it until the hub leaks grease”, then sending it in for an IRAN specifically asking for the hub to NOT be NDI’d is the way to go. I asked how many hubs test bad, they almost none.
Give Jimmy Gaither a call at South Coast. He is one of the most honest and honorable businessmen I know and stands behind his work.
Prop pickup from my hangar, 4 bade repaint, blade seal replacement, repack, rebuild, balance, return to my hangar was about $3500.
I’m not going to worry about my prop again for a long time!

FWIW, my opinion is that TBO’s are often set ridiculously low. Props are the worst of the bunch. My metal prop is 6 years or 2000 hours, whichever comes first. I do understand some time based potential problems but, really, who flies 300+ hours a month and isn’t it use that wears things out? At any rate, mine is well over TBO.

One of the biggest benefits of membership is that you have access to a database of over 1.1 million posts, the majority of which are relevant to current operations. Referring to them and accessing them doesn’t preclude new posts on subjects, of course, but there is tremendous value in that accumulated wisdom and it would be silly and impossible to re-create all of that content every time a question came up on a particular subject.

Stay tuned later this year for a greatly-enhanced search capability. Secret project!

Can we get an iphone friendly design?

Yes. That is coming sooner than the search thing.

Any idea why most pictured attached to posts don’t show up on my iphone using the COPA app? Can anything be done on my phone to correct that?
Sorry for the thread creep!

Yes: Wait just a few weeks for the new COPA site

I’ve read many articles, spoken to 3 prop shops, 2 A&P’s, Hartzel directly and waiting on more.

100% consensus is date TBO is essential on these items…composites in particular in my case. The foam/glass/epoxy needs to be examined, and the bearings and seals have a limited life. One shop in particular pointed out that a low hour plane is particularly susceptible to hidden corrosion.

You guys can complain about non members and your website all you want, but I don’t actually own a Cirrus yet and would love to join this organization is/when I do own one.

I am an 18-year COPA member. I don’t complain about non-members or our website. So I guess I am not one of the “you guys” you are referencing.

Nonetheless, I do have a very strong opinion that anyone contemplating a Cirrus purchase should join COPA before he (or she) purchases a Cirrus. Not after. Trying to defer paying the $65 seems like an incredibly poor decision. False economy.

If you fixate on one aspect of maintenance - relying exclusively on vendor advice - while remaining blissfully unaware of countless other issues, it seems (to me at least) far more likely you will be unhappy later.


A 2007ish Hartzell Composite? I’d be especially concerned. Did the owner comply with HC-AB-306 rev 4 Propeller Blade Inspection? Copy attached.

For anyone interested, Aviation Consumer will publish a report on prop overhaul in its March 2020 issue. AvWeb teased it in this youtube video released yesterday.

ASB306-R04-C.pdf (485 KB)


I decipher your initial post as looking for confirmation that time and hours are the safest, essential, most prudent or whatever you want to call it determination to overhaul the prop.

You found it. You made a statement of “100% consensus”.

I disagree.

Get your concession from the seller based on the confirmed bias.

I have joined several on-line forums after I made a significant purchase to find out more about what I had done.

In my case, i made poor choices. I could have done better in finding a more suitable model, option or stayed away from known trouble spots.

Let my life be a lesson on what NOT to do.

Join the forum, get the details, do research, make better informed decisions.


Agree 100%, that’s what I did. I also joined the Soaring Society of America (SSA) a year before I purchased my Glider.