Damage to little-used aircraft engines ?

Gary R. · #1 11-04-2010, 10:45 AM

Can aircraft engines incur adverse effects from simply sitting in a hangar and being flown very little during the year?

I've always heard they could but I have never seen any conclusive articles written on this subject.

Can anyone shed any light please?

cjensen · #2 11-04-2010, 10:50 AM

I don't have any specific articles to point out, but the biggest issue is moisture...there's always moisture in the engine, and if left to sit, the oil that coats the engine inside will eventually works it's way to the sump, and leave precious corrosive metal exposed to the moisture. Left long enough, and the engine will seize itself.

Even getting it out to run on the ground isn't good enough to keep corrosion at bay...the engine has to be brought to operating temp to disperse of moisture. That means flying it frequently...

Auburntsts · #3 11-04-2010, 11:03 AM

John Deakin has an article over on Avweb that among other things talks to non-usage as why it's a bad idea:

http://www.avweb.com/news/pelican/182045-1.html

Ron Lee · #4 11-04-2010, 12:36 PM

When I am putting my plane in the hangar I open up the oil filler cap and let the moisture out. Then I hook up an engine dryer to the crankcase vent hose to keep pumping dry air in.

I have recently started using Cam Guard as an additional protective measure.

Snowflake · #5 11-04-2010, 12:45 PM

It does less harm than pulling the plane out once a week and running it for 10 minutes.

Are you thinking in terms of winter storage, or longer term?

SHIPCHIEF · #6 11-04-2010, 11:26 PM

Combustion forms acids and water that collect in the oil. Oil has buffers (high PH) in it that neutralize these acids. Acid attack is an ugly thing. My son just bought a 1966 Bellanca 260. It sat unused for 15 years. The owner started it up occationally to keep it good. NOT GOOD. The only reusable parts were the crankcases and the cylinders! This was an engine with 250 SMOH!! Boy was it UGLY!! (rust everywhere)
If you are going to put an engine in long term storage, it must have clean oil, and you might consider some oil intended for storage.
We bought a Cessna 182 that had been stored with AeroShell preservative oil, and had dessicant plugs in place of the upper spark plugs. It was stored 3 years. I wonder now if that was too long.
Others fill the engine with oil to the top, I don't think I've actually seen that one. It would probably drool some out the crank seal, and other seals like into the mags. Seals have limits too.
If you do store it for several months, do not start it or pull the prop through until you are ready to actually fly it and bring the oil up to full temp for a half an hour.
This experience has totally change the way I look at used engine ads on Barnstormers.

Bob'sRV6A · #7 11-05-2010, 08:11 AM

But will not use it for a few years.
It will be run for three hours on a test stand then stored for a long time. Oil change for sure, anyone have a suggestion on which oil? Also, has anyone used one of these:
http://www.aircraftspruce.com/catalo...s/engsaver.php
Even though pricey, it seems like a good solution.
Thanks,
Bob

Greg Arehart · #8 11-05-2010, 09:52 AM

Bob,

You can build one of those pretty cheap - a big plastic jug, some dessicant, tubing and an aquarium pump. Put it on a timer if you don't want it to run continuously.

greg

Lemmingman · #9 11-05-2010, 10:06 AM

I remember several years ago an acquaintance needed to store his 172 while he was going to be in Iraq. His AP had a whole manual on storing (and removing from storage) an engine for awhile.

I did a google search of "Lycoming engine storage" and came up with several links that looked promising. You might be able to find something more specific for your particular engine.