You also have to find a cooperative IA who will sign off on the return to service after inspections of an aircraft with an over TBO engine.

Not so easy. And when you find him and get it done the airplane just dropped another tone of cash. The next upturn in fuel will put to rest these questions, as nobel as they may be.

Alan and Erwin,

I operate a fairly large repair station, we would return the aircraft to service just as Cessna the manufacturer would, As noted in my earlier post, with a note that the operator was advised that the engine was beyond its recommended TBO or HSI interval.

P&WC P6 engines enrolled in on condition programs often go 6000-8000 hours between overhauls. Many turbine engines run these type of hours, the failure rate of JT15D engines is very very low. Again I would advise a close inspection of the HSI as if there is an issue with these engines that and the tower shaft would be the areas that would concern me. The APU on the Boeing 747 I believe is a JT15D, anyone out here know what overhaul interval they see?

Due to overhaul cost many of the Citation airframes are not economical purchases, some with total times as low as 3500 hours, the TBO of the engine. The Citation is a well built airframe, very well supported by Cessna. Many here on Beechtalk would be happy with an airframe with a 3500 - 7000 hour airframe on aircraft with a far lower build quality. If keeping these airplanes with amazingly reliable engines going another ten years or more, I am happy to invest my time perusing this. From what I learned today this is perfectly legal for a Part 91 operator.

As for the fuel price, a newer Williams powered aircraft with far better fuel specifics will cost several million more than an JT15D powered aircraft. That will buy a lot of fuel.

FWIW if I understood Sierra correctly, they were requiring a Hot Section Inspection if you have reached TBO and the Hots were due, in order to put in on their program, which I'm pretty sure doesn't exist. Part 91 doesn't need a program. All life limited parts must have cycles remaining. Preferably enough cycles to get to the next interval. Sierra has changed ownership, and I'm not convinced they're going in the right direction. Or, I should say, in the direction they used to go in.

Robert

To OP Steve, thanks for posting on this subject. I look forward to more info.

To Mike C. Thanks for your input also.

Very interesting.

Robert

Once the early model 525 series on the market began selling for around $1 million, the old legacy 500/501's were toast. I don't know why some people are in denial, and think these airplanes have resale value. There's 56 of them on controller.com alone, and none have moved in months.

I don't know about the ones listed on Controller, but I do know there is a robust market for a properly priced 501SP. There are still some people that like lower cap cost, maybe a little higher op cost. The flat floor in the 501s are nice too. Freedom from the Williams engine mafia is not all bad. I've owned and flown both. I really like the 525s. I think some 501SPs can be good values in the right situation.

Robert

There comes a time when "older" aircraft reach a point of "diminishing returns". The term "older" is somewhat subjective based on the type of aircraft more than just years and is different for business jets than piston singles. However, the term "diminishing returns" means that, from a market perspective, the airframe has very little or even no value (it may even be negative in some cases - as an aircraft) and the components such as the engines, avionics, etc. have significantly more value if sold separately and then the airframe is sold for scrap. It is one of the reasons banks tend to shy away from "older" aircraft because any serious issues such as repairs from damage, major repairs, etc. can cost more than the aircraft is worth and it changes the risk profile for them.

I run across these situations routinely as an appraiser. The aircraft is still flyable and it is still airworthy but the decision to repair or overhaul becomes more serious at this point in time.

Good luck.