Found a red one.

A red dikky? Sounds like something there's probably a prescription for...

I'm not sure it's the wine or the Mike C convincing post but I'm intrigued to learn more..

No s#@t! I need to close the laptop!

You think it's hard to resist from looking at a pic and listening to us, wait until you fly one.

You don't like red? Hmmph.

On my airplane, we pulled an engine to make an adjustment on something. In less than 2.5 hours, the engine was removed, adjustment done, and reinstalled. I was amazed.

The system was designed for rapid engine swap. The majority of the electrical signals run through a massive Canon plug. Bleed air line, starter heavy wires, fuel, oil cooler lines, and some control linkages complete the disconnect. Then it is two pins that hold the engine to the wing spar, one rear bolt, and out it comes.

Here is a pic of the engine just after removal. Note how clean and open the engine bay is with the clam shell and top cowls open.

And now back on the wing.

Mike C.

Now let's compare what it takes to deal with the starter adaptor problem on a TSIO520. 30 hours of labor if you're lucky to remove a ton of crap and then reinstall it. Every 500 hours or so. Piston twins are simply not designed with maintenance in mind.

You don't like red? Hmmph.

Is there any negatives to the MU2 not flying as regular as to comparison to a recip. ?

Obviously aircraft like to fly (just like any machinery). Guidance from Honeywell is that the engines should be started at least once every 30 days. A lot of owner/operators of MU-2s are casual flyers and amassing less than 100 hours a year (turning their 100 hour inspection into an annual). You'd be amazed at how many seem to run right in that 80-99 hours per year sweet spot.

I went to recurrent training last year with an older gentleman who is on his second MU-2 (and he bought his current plane brand new back in '81 or '82). Plane has less than 3000 hours on it...he only flys it VFR now (managing his risk as an older pilot) and recognizes he really doesn't need or use the plane the way he used to but just doesn't want to let it go. He flies it maybe 50 hours a year with no problems (from an MX perspective). Obviously his hourly costs are quite high since he still has to do the 100 hour every year, but money isn't an issue with him.

Keeping a plane in a hangar protects the airframe from lack of use. Turbine engines stand up better than piston's to lack of use because the turbine isn't subject to the start up damage that a recip undergoes when used infrequently (scraping the cylinder walls).

Further, piston engines by design, try to destroy themselves during the combustion events. Parts are constantly being stressed and pulled in different directions. Vibrations, etc.etc.etc.

Turbines spin smoothly. No weird dynamic forces constantly pulling in different directions. Turbine bearings for the most part are ball or roller type, not plain like you find in recips.

It seems the physical size of plane and then the intended use dictates if it is feasible to run a turbine or not. Small planes (e.g., cirrus) = pistons large (e.g., Pilatus, ag tractor) = turbine

The allison 250 that is installed on P210s is about the smallest turbine I'm aware of. By the time the install is complete, the plane, is considerably larger (i.e., wing span due to extra fuel required, longer, due to length of powerplant, etc.)

Net - we are stuck with pistons on small planes, but as soon as you move to something a notch or 2 bigger than a Baron or 310, turbines become possible.

Sorry for the tangent.

Knowing who is probably doing the MX (is it Bob P.) He has the ethic that he wants to keep these planes flying , more than turn a profit.....You are lucky to have Bob on your team....

Bob is the man, but I use Jet Air for this airplane. Those guys have been doing MU2s for a looooong time, they're straight shooters, and theyre a four and a half hour drive away from my Portage, IN location- and they even give me a car for a few days while they do the inspection.

Turbines sit better than piston.

The parts exposed to the air don't rust. Compressors, turbines, stators, ducts, etc. The gear case is far more sealed than a piston. For one thing, the volume inside doesn't change due to piston movement, so the gear case breather is much more restrictive and that keeps air exchange and corrosion down.

But you still need to fly enough not only for the machine to stay healthy, but for the pilot as well.

Early on, if I didn't fly in 2 weeks, I felt very rusty in the MU2. Now, if I don't fly for 3-4 weeks, I take a local training flight, usually do a few approaches. That knocks the rust off both man and machine pretty well.

Mike C.