I didn't have 3 green on the gear. I was being vectored to final, broke off from final and troubleshot the problem. Even though I had just finished my training, under the stress of the situation I had forgotten that on the MU if you have any green they are all down and locked. Having forgotten that tidbit, I was glad that it was day VFR and I just flew the plane and gave myself the time to think about how to handle the problem. I did a fly-by the tower, was told that they all appeared down and I went in for the landing prepared for the worse.

Those jokes are getting so old.

Couple of updates from today. Flew to TN to observe some work being done during the 100hour and pre buy.

Your plane is missing a wing.

Wow, engines and wings come off for 100 hr?

Apparently so. Takes about 20 minutes to remove and makes inspection much easier.

That is both frightening and inspiring at the same time. These things were designed well for both performance and maintenance/longevity.

Hope that you enjoy your new bird!

To clarify, the engines usually come off the wing at 100/200 hr inspections as it easier to get to the starter gen brushes;also the upper fuel nozzle is almost impossible to change without pulling the engine (pre -10 engine).

A outer wing pull takes about 2 hours per side; about 4-6 hrs each to reinstall and rig the entire flaps. One of the benefits of being built in modular components in Japan, shipped to San Angelo for assembly.

James, if you have time stop by Aiken, SC and see the warehouses that Air 1st has of parts.

They have enough to parts to build 10-15 airframes just from NOS parts.


Regards,
Nigel

Holy cow.....that is 16 hours of labor for every 100 hours of flying and that does not include the actual inspections. Sounds like a lot of time to me.

No.

My wings have never been off, in 40+ years, as far as I know from reading the logs.

James is replacing an outer tank. That is about the only thing that requires a outer wing panel pull since it slides in from the panel root. Doing this is highly unusual.

Engines are another matter. An engine can be off, adjusted, and back on in 2 hours. Mine have been off twice in 8 years.

The pre -10 engines have an upper fuel nozzle that is very hard to get to on wing, so the engine usually comes off to change it. For my -10 engine, nozzles are easier to get to and no engine pull is done.

Since the airplane was made in prefab assemblies in Japan with final assembly in Texas, there are convenient disconnects for wiring, hoses, controls at the junctions. This makes heavy disassembly of an MU2 quite a bit easier than the typical airplane.

Mike C.

It looks like an opportunity for maintenance induced failure. It also looks like the plane would need a pretty extensive post flight checkout. With the engine having been removed every gage, power levers, condition levers and all their functions would have to be checked. It sounds like a multi-hour flight at the minimum. What is the all in cost of a 100/200 hour inspection (including fuel)?

Engines designed to come out in an hour are generally a couple cannon plugs and reinsertion of a couple clevis pins.

Not 100% sure on the Mu-2, but on the E-2 it was connect three electrical cannon plugs, four hydraulic lines, two fuel lines and the three phases off the generator.

I suspect that the Mu is similar or even simpler.

This is piston think applied to turbines.

The engine rigging is retained due to simple disconnects.

Electrical connections are through one large canon plug outside of the heavy lugs for the starter/generator.

Checkout is minutes and done on the ground. You'll know during the start how torque, RPM, fuel flow, temperature, oil pressure/temp are doing.

Engine removal is really no big deal, nothing at all like a piston engine.

Mike C.

Yep. The longest part of most turbine engine changes I've been on has been getting it down to the hangar deck.

Helicopters, most turboprop and pod mounted jets are simple to change or temporarily remove to facilitate other maintenance.

(Fighters are a different story)

So there are no mechanical cables going to the engine? All engine controls (throttle, condition lever etc.) are electrical? That would make life easier.

Vince