Q: What are your thoughts on propeller TBOs? Seems like everyone in the industry says overhaul every six years due to hidden defects and corrosion. Owners and brokers claim “nobody does that.”
Any advice appreciated…
DAVID FARMER
A: Dave, this is a commonly asked question and has a very simple answer.
Most external accessories on any Lycoming engine will have the same recommended TBO time as the specific engine model as set forth in the latest revision of Lycoming Service Instruction 1009.
However, any accessory, including propellers, must comply with the recommended maintenance and recommendations of the original manufacturer, including TBO times.
I’d suggest you work closely with your maintenance facility, which will be familiar with any product information the manufacturers may require.
Some accessories may require some type of action as required by the original manufacturer prior to the TBO time listed by Lycoming for the engine.
While I understand that you may hear “nobody does that,” I’d be hard pressed to agree with that type of mentality. Safety is the number one issue here and there are no shortcuts.
Please keep in mind that TBO times are established by the original manufacturer after years of evaluations, both from an engineering standpoint and in service life studies. The data collected from this approach is responsible for the issuance of service bulletins, etc., should some interim action be required.
Just remember, even though we may not be thrilled with a recommendation for action on a component, it’s really difficult to explain after the fact why you chose not to comply with a manufacturers recommendation should an incident occur.
A review of the last 20 years of NTSB data showed only 2 propeller failures, and they were fixed pitch props with part of a blade separating due to a fracture.
https://www.ntsb.gov/_layouts/ntsb.aviation/Results.aspx?queryId=1db021a5-bfc5-4b41-bc4b-c764afacf2e7
So…?
Knee jerk response that’s way off the mark this time and makes no sense for part 91. Sounds like a great way to spend more money to be less safe.
Doesn’t a lot depend on the prop itself? A constant speed prop has vulnerabilities not present on fixed pitch props. CS props should be given greater scrutiny. The condition and history is another factor. A fixed pitch metal prop without nicks or previous incidents or repairs should go beyond TBO without worry. TBO is an arbitrary figure, likely a very conservative figure, designed to protect the manufacturer. A well cared for prop doesn’t disintegrate at TBO.
I mentioned to my FBO that my engine was several hundred hours past TBO but still running strong. He said when that engine quits you will have about 40 seconds to think about ignoring the recommended TBO.
For my continuing longevity I shall follow all TBO.
One of the most uneducated ridiculous responses I have ever heard. Sounds like your local FBO has your Platinum card on file…. There is absolutely nothing on an aircraft more dangerous than a freshly overhauled engine – NOTHING
I feel more comfortable flying behind a 2000 hour engine that was well maintained than a 0 time engine right out of the factory. Statistic don’t lie and statistics say infant mortality is real.
Nothing more dangerous that something that has just been “freshly overhauled”. People really show their ignorance when they say if you don’t follow all manufacturers recommendations your betting your passengers lives and shouldn’t own an airplane. There is an incredible amount of maintenance induced failures. Aircraft hanger kept, 50 hrs a year , does not need a prop overhaul every 5 or even ten years unless there is an issue. Just ridiculous.
The fact is that the vast majority of Part 91 aircraft do not get prop overhauls at the manufacturer’s recommenced TBO, usually 5 yrs. Where is the epidemic of prop failures? It just does not exist. Service history has proven that the risk from extended prop usage is very small.
Poorly written article this time. Part 91 aircraft clearly do NOT have to follow the TBO recommendations.
ALL aircraft operating commercially, such as FAA FAR part 121 or 135, MUST follow manufacturer recommended Times Between Overhaul (TBO) and approved maintenance manual chapter 4 component life limits. As most owners know, aircraft operating under FAA FAR part 91 are not required to follow manufacture recommended TBOs. The National Transportation Safety Board (NTSB) records most all U.S. registered aircraft accidents. The NTSB website records these accidents in a chronological order. Read through those accident reports and determine for yourself if following the manufacturer recommendations are necessary for you:
http://www.ntsb.gov/_layouts/ntsb.aviation/month.aspx
If you don’t feel you or your passengers health and well being are worth the standards commercial operators are held too, just don’t sue the manufacture and everyone else when you end up on this NTSB list. Insurance companies use algorithmic calculations for our premium’s pricing. When your family sues the aviation industry providers because of your lack of self concern, all of us not dead have to pay. Manufacturer Recommendations are not just money grabs they also are good practices that reduce catastrophic outcomes.
I know of no aviation insurance company that require their Part 91 clients to implement manufacturer ‘s Service Bulletins or TBOs. That should be an indicator of the efficacy of the SB and TBO. If Insurance companies even suspected that SB and TBO reduced accidents, you can bet they would make it a requirement, regulation or not.
Paul- You make an assertion that accessories and propellers must comply with TBOs. I don’t believe that is true for private Part 91 use. If you believe you are correct, please point to the regulation.
I believe the best rule of thumb on propellor maintenance is if has been an actively flown aircraft without leaks then keep flying. OTOH, If it has any leaks, or has been in disuse, then maintenance is probably warranted.
A prop blade failure cannot shake the engine out of its mounts. Plays heck with CG. The church will mshift way aft. A spin will be unrecoverable.
The least of your worries is a leaking seal or a governor failure.
A prop overhaul includes x-ray and other nondestructive inspection. The forces on a prop are many thousands of pounds.
It is your life and your famil lies. If you can’t afford the prop and other TBO overhauls you can’t afford that airplane.
CAN SHAKE
I couldn’t agree more. If you can’t afford the recommended overhauls, don’t own the aircraft.
This was not a response. I like a lot of Paul’s advice about oils and fuel but he oftentimes gives “no advice “ opinions like this. Would be better just to say can’t address honestly because ….. We need to get someone who is candid to respond to questions like this. This kind of response makes me doubt if he is being candid about other subjects too or just parroting canned advice like this on behalf of industry interests.
That was a marketing response….
Yes, it’s apparently a marketing response. A lot of TBO requirements were made before we had a more modern way to monitor our engines and accessories. It’s strange to read this from Paul…