Hangar Queens - what to look for

[Dan]

If one were to consider buying a hangar queen, what items should one look deeply into  for issues? I assume there are things that will start to dry, or not move easily or otherwise suffer from neglect.  What might be some things like this?

 

Thanks

Dan

[GeorgePerry]

Group the airplane into 3 catagories.  (1) Engine (2) Airframe (3) Electrical / Avionics.  All the other stuff might get old but shouldn't be a safety of flight issue.  I'd do the inspection in this order since to test certain systems it's helpful to have the engine running.  If the engine doesn't pass step one, there's no need to continue.  Infact running an engine with corrosion may "hide" issues that would have otherwise been noticed in an engine that's sat idle for months.

First the engine.  Motors that sit and are not flown regularly need to be throughly inspected.  I would pull the jugs off so an A&P can get a good look at the internals.  Corosion inside the engine is BAD...and expensive, and will basically require a rebuild.  If an owner knows that the airplane will be in storage for a long time, some will prep the engine for such a prolonged period of inactivity, by filling the entire engine with a fogging oil or other perservative type oil.  If that's been done it's a good sign but no guarantee corrosion hasn't started.  Bottom line, pull the top off and have a look inside.  Most A&P's will caution that corrosion can start as soon as 30 days after an engine was last run.  The reason this is important is the oil and internal engine temperatures need to be hot enough to "vaporize" any condensation or moisture that forms intermal to the engine.  Dry climates are better than moist humid climates.

Second the airframe.  This also requires some thorough inspection but it the bird's been well cared for, has been kept in a hanger and some type of anti corrosion treatment was used, it'll be readily apparent.  This should not require too much work.  Just remove panels get a bright flashlight out and look

Lastly the avionics and electrical.  Pretty simple really...Turn everyting on and check all the electrical items on deck.  Don't forget to do this in a dimly lit hanger so you know if the "little" things like post lights ($20 to replace one) are working.  If the avionics powers up and tests good then you should be OK...They don't wear out like other parts.  One a set of Jackstands you can run the gear (if it's electrical).

[Guest Anonymous]

Leaks - especially fuel leaks on a Mooney, leaks can mean seals, and seals can get expensive to replace or repair.  They are also indicators of brittle hoses and lines.  Some leaks, like vacuum ones can only be found with the engine running.  Others will be best discovered as soon as the hangar door is opened, before the aircraft is moved.  The remaining ones will form little pools in the bottom skins - especially oil ones.  They will not always be liquid if the airframe has sat a long time, instead they will form a puddle of a grease like material or a thick film.

Rig - a simple check of the ailerons against the training edge of the wingtip and the flaps relative to the ailerons can say lots about previous maintenance.  Also, don't force any surfaces, but lightly check the "play" in the ailerons and rudder.  This kind of thing is usually easy to fix, but is a good indicator of neglect.

Log Books - When I was shopping for an airplane, I found a Mooney that has the previous six years of entries for annuals and static inspecition ALL IN THE SAME INK AND ALL SIGNED BY THE SAME A&P, and all of the writing looked alike with no owner or other mechanic entries in between.  Each annual entry had EXACTLY the same wording with no corrective items on any of them.  Those entries fairly screamed, "PENCIL WHIPPED" to me.  Maybe the mechanic was honest and simply catching up, but I threw that one out -- quickly.  Another thing I learned to do if the aircraft was owner flown -- compare the owners pilot's log to the aircraft logs.  On that same aircraft, the owner had not flown for four years due to loss of a medical.  MAYBE it was flown the indicated minimal hours, but maybe not.

RFB

[Kwixdraw]

All good info above. Add corrosion/rust to general surfaces like the chrome control yoke shafts or sliders for the door and baggage compartment or chrome bezels on switches-avionics. Though these are not in themselves critical you may get a sense that the plane has been around considerable moisture just through heating and cooling condensation. Get an interior panel off up near the window area and look for rust on the steel tube structure and corrosion to the screws that hold the aluminum brackets that join the steel to the outer skins. Corrosion to those screws can give an indication that there could be water inside the steel tubes and deeper investigation is needed. Look at the spar cap inside the wheel wells. Corrosion here is serious. Look at the skins near the battery for acid damage.  Have someone who KNOWS Mooneys show you what to look for or do the inspecting for you. Good luck in your search.

[Dan]

Excellent information. Much much appreciated.

[Piloto]

Planes in proper storage could be in good shape after all the Spirit of St. Louis has been is storage for over 83 years with no signs of corrosion. A good clue for storage conditions is the hangar itself. Check the hangar structure itself. Look for any significant corrosion on the internal structure members. This will give you a hint on the environment the plane has been subject to. Airframe corrosion is depent on exposure more than on hours flown. An active plane that parks outside will have more corrosion than hangar queen. Also exposure in the sun will cause plastics and rubber to deteriorate quicker than in hangar storage. A quick check for engine condition is the condition of the cylinder cooling fins. The fins will show significant signs of corrosion before the inside of the engine.

José

 

   

[Parker_Woodruff]

I just started a pre-pre-buy inspection and test-flight on an M20C today that's flown 60 hours since 2002...and the engine was off the plane for 2 years and 11 months in the middle of that.  Big thing is going to be what comes up in the borescope...fortunately the seller has agreed to pay for all of it including new cylinders if Don Maxwell deems necesary.  (only 75 smoh)

Another thing is hangar rodents.  I just delivered another M20C that Don Maxwell opened up and found rodent droppings everywhere.  After a $12k estimate for prebuy that the seller won't pay for, guess who's flying it back to KC tomorrow?   If anyone is looking for an M20C and wants to avoid a certain plane in MO, let me know and I'll send you the info.

Oh and many times hangar queens somehow have the original shock discs on them as is the case with both M20Cs this week.  Those ain't cheap to replace.

Also if the plane just keeps getting annualed w/o flying, the PC connected to the yoke on older models can get out of proper calibration since it's not flying (vacuum based).  Then you get a plane that wants to fly sideways in cruise even with it trimmed as far left or right as you can get it.

The only really good thing is you get a plane that has few logbook entries so sorting throught the gotchas is really easy.