I was sorta defending why you may not be keen on engine programs, your plane/engines are old relative to those being discussed with programs, you're better off without them for the reasons you outline

however, the programs are extremely applicable to a brand new 10m+ financed bird that someone has put 20% or less down on and the bank is on the hook if the loan defaults or the market turns south, or any situation where the plane is being chartered and the bean counters want simple math to follow

"My PC runs slow. How much to make it run as fast as it used to? Whaddya mean you need more info!? I already told you it's Windows 7 and was top of the line when I bought it."

"How much will my divorce cost? Whaddya mean you need more information!? I already told she's crazy and it's a slam dunk case."

"How much will my medical bills be this year? Whaddya mean you need more information!? I already told you I'm 58 and I play pickleball 3 times a week."

I can keep going....

That wasn't my experience when I did the HSI on 2 PT6-112's. True, I didn't know what was wrong until they opened them up and sent me the inspection report. But once I had that in hand, I had options for overhauled parts, PMA parts, serviceable parts, etc. and all that affected the final price. I was even able to negotiate the price of CT blades and a CT vane ring by offering to buy PMA versions directly from the manufacturer at a big discount and hand them to the shop for installation. Don't get me wrong it was bloody expensive but I was able to affect the outcome in my favor somewhat, and I had choices.

Which shop? Sounds like my kind of place that lets the customer be properly involved in the decisions and strategies.

Mike C.

Which shop? Sounds like my kind of place that lets the customer be properly involved in the decisions and strategies.

Mike C.

They are the shop that did a pair of PT6 overhauls for $1M?

Thanks for the warning.

Mike C.

Prime Turbines, specifically the Butler, PA location. Overall I was happy with the work they did and their communication. Of course the price was higher than I wanted but it was probably lower than they wanted which means we were both equally unhappy. The basis of a successful negotiation

They are the shop that did a pair of PT6 overhauls for $1M?

Thanks for the warning.

Mike C.

Wow! I assume those are PWC parts and maybe there aren't even PMA options for that model but those prices really illustrate the difference between "big bore" PT6's and the "small bore" variants. New PMA CT blades for my -112 were $26k per side and a new PMA CT vane ring was $11k. Chump change compared to a -60A!!

Not sure about the CT vane ring, but there are no PMA blades for -60A.

Honestly, based on the history of PMA blades, I wouldn't recommend them!

What is the negative history of PMA blades? I talked to Paul Jones (special turbine) and he said they are a good option. He even said the coating they use at Extex was a little better than PWC. I know that Extex ships tons of the blade used on the -28/-112 engines to the point where it's hard for them to keep in stock. On the other hand, PWC has had terrible reliability with some turbine blade versions such as the ones used on the -114 so it's not like they're totally immune to problems either.

I believe they were from Timken, I just remember they had a bunch of bad blades. I don't remember if it was an AD or what, but know they had failures, like three in a year. I think Timken ended up in bankruptcy over it. It seems like it was recent, but that's a sign of me getting old... was probably 10 years ago or more.

CT blades are under a ton of stress and failures are serious, I wouldn't personally take the risk to save the money. It is rare that Paul and I disagree.

One other important point, if you ever plan to upgrade to Blackhawks, they can only give you value for timed-out cores if you have PMA parts.

If the problem was as simple as "buy OEM parts because they never fail" then yes, the decision would be easy. And yes, CT blade failures are serious as a heart attack. But unfortunately, even PWC has issues with CT blades, which BTW for some models they outsource to an outside vendor.

https://tc.canada.ca/en/aviation/refere ... y-advisory

To my knowledge, the only issue Extex had is that they stopped production of the 3045741-01 due to a QC problem about 3 years ago. The 3045741-01 is used on the -28, -112, and until around 2014 the -114/-114A. The Extex blade is of course an identical copy of the PWC version made with the same IN100 base alloy and platinum aluminide coating. But PWC figured out that the -114A really needed a single crystal blade to hold up to the higher temps and stresses of the -114A so they superseded the old blade design. The -114 was actually subject to an AD requiring removal of the old style blades.

https://www.federalregister.gov/documen ... op-engines

More recently another AD came out requiring replacement of ANY blade when used with a PMA CT vane. There was some debate about the actual cause of this and not surprisingly the PMA vane ring manufacturer submitted some pretty convincing evidence that their part was not really to blame. As part of the fix PWC added some kind of vibration isolator which they wouldn't have done if the only issue was the PMA'd vane ring.

https://www.atsb.gov.au/media/news-item ... -component

https://www.federalregister.gov/documen ... op-engines

I spoke with a PWC customer engineer about this and he said that due to the basic design of the CT vane ring in the -114A it was more sensitive to improper manufacturing and could cause high cycle vibration of the blades.

The bottom line is that you can't really say that buying OEM parts guarantees you safety compared to a PMA blade. For sure PMA parts present problems if you want to turn the engine back to PWC or if you want to use a DOF, but those are mainly economic reasons. From a technical point of view it's a coin flip because PWC has had more than their share of CT blade issues causing several accidents and many deaths.

I'm pretty confident that when it comes time for my HSI, RBR will give me ranges based on what could happen once they crack the case.

But, your assertion is wrong. The medical industry is WAY worse. Not only will they bill you whatever they want and will never give you a price for anything ahead of time, if they screw up they will bill you to fix their screwups too. I had 2 friends go for outpatient orthopedic surgery (at Stanford no less) given MRSA infections in the hospital. One almost died and the other nearly lost their leg. Medical system billed their insurance for the rehab when it was 100% their fault. This is the equivalent of your mechanic dropping your car off of a lift and then billing you for the repairs.

Hi Thomas,

Of course there are risks with any intervention. But let's go back to my mechanic analogy. If the mechanic is working on your turbo and the intake manifold is damaged through no fault of their own (it was already damaged, brittle, worn out, etc), then you should pay for that or at least part of it. But if you get the plane back and there is a dent in the wing because they dropped a hammer onto it, they should fix it as it was solely due to their incompetence. They don't give you the plane back and say, "Sorry, you brought it to the shop and shops are dangerous places."

These were both outpatient orthopedic surgeries at the same facility a few months apart. Both patients were in their 40's and healthy. The surgeries were to fix sports-related injuries from different sports - one from soccer and one from dirtbike riding. So the odds that both of them would pick up MRSA from their environments is astronomically small. MRSA outside of a clinical setting is quite rare anyway. Obviously it could be a coincidence but it is as close to 100% as possible that it was given to them by the facility. This falls into the incompetence area above and the facility should cover it. But because there is no financial incentive for the facility to prevent infection (in fact, they make MORE money if they don't) they will not spend any money to improve their practices. Sure, some people will check infection rates before selecting a facility but because of the way the insurance networks work, you typically don't have a choice in facilities. So people are going to get what they get and the facility makes money no matter what.