Prop and Governor Overhaul

[Richard Lanning]

My first airplane may be my last. This continues to be a real learning curve.

I had mentioned my vibration issues in the past. Annual is done with nothing major noted. Last option is to get the prop balanced. Took it to the shop and have discoved props have calendar TBOs along with hour TBOs.

My three bladed McCauley only has 650 hours on it but it was installed 15 years ago. I am told it has a 5 yr TBO so they won't balance it until I get it overhauled.

Quoted cost is about $5000 for prop and governor. Any thoughts on any of this?

Just want to make sure I am doing the right thing. Thanks!

[N3322G]

Richard,

I can't say you are doing the right thing to solve your vibration problem but can share that the props on my Twin have a suggested 5 year or x number of hours overhaul. The last time I had them done the estimate was $5,000 each but the final total was greater than that.

[Kristin Winter]

Unless there is an AD on the prop, there is no requirement under part 91 operations to overhaul that propeller. Find another shop to balance it. They may be trying to sell you something you don't need. Even if I was worried about the calendar time because the prop had been sitting unused and I was worried about corrosion, I would only send for a re-seal and inspection. Those are about half the price of an overhaul.

[Andrew Foster]

I just had the same prop on my 250 dynamically balanced. 200 dollars. Installed in 2004. An overhaul here in pricey so call is 2000-2500 depending on where u go. I would heed kristins advice and find another shop. That seems way out of line.

Andrew
61 250

[Ed Asmus]

I'm in agreement with the last two posts. Find another shop to balance the prop!

Ed

[Pat Elliott]

Are you flying part 135? No? Manufacturer recommended tbo's don't apply to you.
Find another shop.

[Richard Lanning]

Thanks everyone. This has been very stressful trying to decide what to do.

[N3322G]

Richard,

I may be in the minority here however, I'm a firm believer in continuous maintenance.

If the new-to-you aircraft had been inactive in the past, the prop may very well need attention. It could be the cause of the vibration - can't tell from here.

There is clearly a regulation difference for the kind of flying most of us do in our Comanches. My experience is to listen to the more stringent commercial regulations and watch carefully which might need to be applied to my Twin.

A few years back I was at a shop that recommended the check valve that controls whether one vacuum pump can back up the other one on my Twin, be O/H'd. They mentioned it because that was what brought down the Missouri politician's twin engine aircraft because it is darn difficult to fly IFR with no vacuum system and it killed all on board. I elected not to O/H at that time. Previously I had not had a pre-flight or shut down process to watch for this so I instituted one. Sure enough about a year later, that check valve failed. If I hadn't put the new procedure in place and if I hadn't listened to what is required for other operations, I would not have known - and that was after 40+ years of being around this aircraft.

Hopefully this is some food for thought.

[Ed Asmus]

Richard,

My first post may have been a little too brief. Because you are trying to solve a vibration problem and you or your shop suspects a chance it could be the prop, if balancing the prop is what you want to try, you can certainly do that. No overhaul, reseal, or anything else is required to accomplish the balancing. Plenty of shops will be willing to do that. "Continuous maintenance" as Pat mentioned is a good thing and I'm in agreement with that. 15 years would be longer then I would go without having the prop disassembled, inspected, and resealed even though it is not required maintenance by regulation. What you need to make sure is you UNDERSTAND what is REQUIRED by regulation and what is not. Just because a shop says something has to be done doesn't make it true. I'm not saying that means you should not consider the advice but you need to understand what you have a choice on and what you don't. Maintenance, like flying, is about good judgement and common sense. There are some things in airplanes we can operate to failure with an acceptable increase in risk. There are somethings in airplanes we cannot operate to failure because it causes an unacceptable increase in risk. Operating a prop to failure would cause an unacceptable increase in risk so as a result, props require periodic disassembly and inspection. (This does not need to be an overhaul necessarily). My personal choice has been to send my props out every 5 years for inspection and reseal though I am considering lengthening the interval by a year or two because over the last 24 years of airplane ownership, my experience has taught me that nothing has been discovered on previous inspections to cause alarm. My aircraft are stored in heated hangers in the midwest. If I lived in Florida for example, my methods would be very different. That nice warm muggy salt air does bad things for airplanes so common sense and good judgement would dictate more aggressive maintenance procedures. Do you get the idea? I hope this helps. I remember my first experience with airplane ownership decades ago. It was a 180 PA24. The maintenance bills were shocking. I know how you feel. Airplanes are wonderful but they do come at a substantial price. Good luck!

Ed

[Michael Duncan]

Richard,
While the 15 years is a long time has the aircraft been hangared or does it sit out in the weather. Personally as an A&P I tend to be more on the conservative side of mx. I also don't believe in doing mx just for the sake of it. There are times when you can cause as many problems as you fix.
In your case I would opt for the reseal and that'll at least get a look inside the hub. If no corrosion is present and everything else looks good then go ahead with the balancing(as others have already said no reason you can't do it now) and you will be good. Plus the reseal will cost you only around a half or maybe less of what a full blown overhaul would.
Just my two cents,
Mike

[Matthew Sawhill]

I hate to hear new owners having bad experiences with aircraft maintenance. Please stick it out - it's worth it in the long run!

My prop shop (Maxwell in Minneapolis) has always been willing to share their perspectives on maintenance of various props. Their insights have helped me strike the right balance between saving money and ensuring a long, reliable service life. Each make and model of prop has its own set of characteristics, and an experienced shop should have good insight on how to get the most out of your specific setup over the long run.

You might call one or two prop shops to learn more about your prop so you can be more confident in your maintenance decisions. I might ask about the following:

What are the general strengths and weaknesses of this prop from an operation and maintenance perspective?
What are the indications that an overhaul is needed?
What issues should an owner watch out for if the prop has not been to the shop for 15 years?
Outside of commercial operations, what service intervals are recommended for a private owner who wishes to be a "good steward" of his/her aircraft?
What issues with this prop could cause vibration problems? Aside from the vibration, are there other signs of these issues that an owner should watch for?

Aside from helping you learn about your prop, talking to a few shops in this way can also help you figure out each shops' philosophy on balancing their customers' interests vs. their own.

Good luck!

M

[Kristin Winter]

Matthew,

Are Kenny Maxwell's kids involved in the operation now, if you know? I used to use them for the charter fleet in the 80's and early 90's when Kenny was still alive, but probably in his eighties. There wasn't much about propellers that Kenny didn't know.

[Charles Schefer]

Rich,

Sorry if this is ground already covered but... I know the previous owner of my PA-30 had a horrible time with vibration issues a few years before I took ownership. The logs are full of entries including prop balancing and swapping props left and right, etc...

The previous owner told me the problem was so bad he was ready to throw in the towl and sell the plane but then he discovered the problem... He had installed new engine mounts. Someone troubleshooting recomended different mounts. He switched to those new mounts and the problem was solved. He had many years of trouble free flying and then I bought the plane.

Hope this helps,

- Charles

[Timothy Poole]

Richard -- Not sure if you are still battling this issue but wanted to chime in. I also had vibration problems in flight. I balanced the props which had no discernible effect. We installed new engine mounts yesterday and this Twin Comanche has never been so smooth in flight! Good luck with resolving your problem but give the mounts some serious consideration before you go sinking money into the props.

Tim

[N3322G]

Ditto Tim's comment on engine mounts. Zach Grant at an education session recommended every 4 years. I was surprised how much difference it made.