What to expect of an airplane that was sitting for long

[redbaron1982]

Hi all,

On December last year I bought a Mooney M20J, and since then it has been a nightmare. Annual inspection took 4 months, and found wing spar corrosion and the shop was not able to fix it. So 1 month to ferry it to Don Maxwell. And now at Don Maxwell they are waiting for the part from Mooney that is supposed to be ready by end of August and the repair will end up by end of September.

All in all, the airplane will have been sitting for 10 months (hopefully not more), with a few runups during the annual and for 2 days when it was ferried from Boston to Longview.

What to expect when I finally get the airplane back? My main concern is if this will end up in a shorter engine life (corrosion due to the engine not running) or any other thing. Also any adivse on the best way to bring it back to regular flying would be appreciated.

Thanks!

[Ragsf15e]

At least it’s not sitting in Florida.  It’s not in a terrible climate there, so I’d have my fingers crossed and hope for the best while monitoring the oil and flying it a lot when you get it back.  There’s not a lot you can do at this point.  My engine has been down a few similar times since overhaul in 2004 and it’s been fine each time we got the chance to see lifters/cam.  You might be just fine.

Generally, oil analysis might see some additional wear metals on the first one or two oil changes but it should drop.  If your cam or lifters spall, you might not catch that in oil analysis, but could see bigger chunks in the filter.  I’d definitely inspect the screen and filter carefully.

[carusoam]

To avoid engine corrosion…

Read up on engine dryers and how they work…

There are a few threads around here regarding their use and construction.

Keep fighting the good fight!

-a-

[Guest]

Kind of late now, but preserving oil and dehydration plugs won’t hurt while it sits.

Clarence

[Pinecone]

One would think that a top shop would suggest pickling the engine once they get a multi month estimate for parts

[ArtVandelay]

Since you did an annual, I assume the oil was changed and hasn’t been sitting with dirty oil.

[redbaron1982]

4 hours ago, ArtVandelay said:

Since you did an annual, I assume the oil was changed and hasn’t been sitting with dirty oil.

Yes, oil should have no more than 10 hours on it.

11 hours ago, M20Doc said:

Kind of late now, but preserving oil and dehydration plugs won’t hurt while it sits.

Clarence

I didn't know about the dehydration plugs, otherwise I think I would had ask the shop to put them.

[PeteMc]

Being in TX, would it be safe to assume the shop/hangar has air conditioning?  Even if they don't crank it down to 60, they're still pulling a LOT of the humidity out of the air.  So that should be a big plus.

[Wildhorsetrail]

IMO, 10 months isn't going to be that serious. Probably if you did this every year for the next 5 it would. I don't know as much about the Lycoming engine, but I know of a Cessna 172 with a Continental in it that was flown infrequently from new (1961) all the way to TBO in 1996. It sat for many months at a time during that period. You don't seem to hear those stories, you only hear the horror stories. The engine also was only equipped with an oil screen (horrors) but that didn't seem to shorten it's life any either.

[A64Pilot]

19 hours ago, M20Doc said:

Kind of late now, but preserving oil and dehydration plugs won’t hurt while it sits.

Clarence

This is the best answer, I “pickled” my C-140 for about three years with no issues.

If you know it’s going to be over about 60 days, I’d preserve it. Keep the preservative oil, it can be reused. The 60 days is just an opinion of mine, wouldn’t hurt if you preserved it and it was only a month.

[A64Pilot]

7 hours ago, PeteMc said:

Being in TX, would it be safe to assume the shop/hangar has air conditioning?  Even if they don't crank it down to 60, they're still pulling a LOT of the humidity out of the air.  So that should be a big plus.

I have a two ton Split AC in my hanger and have the thermostat set to turn on at 65% RH and off at 61%, it doesn’t run all that much and I’m in Florida.

‘It doesn’t take much AC to really knock the humidity down.