How to Take Care of a Mooney Mite

Congratulations on getting an M-18 Mite! Here is some useful information on the care and feeding of the airplane.

Keep in mind that the Mite is a wood-and-fabric airplane and thus is subject to normal deterioration. You should pay close attention of the condition of the wood, looking for discolorations caused by dry rot, and also look for glue separations. And of course the condition of the fabric is something to look at. Most of the planes have been re-covered with Dacron fabric, which will last for many years if the plane is kept in a hangar.

The Mite does have a tender spot which is worth watching, and that is the tail assembly. Mooney's trim system rotates the vertical and horizontal stabilizers as a unit, which means that there is extra stress on the pivot point. What you can do is take hold the outside end of a stabilizer and check it for up-and down movement. There should be very little play (relative movement) other than flexing.

Another critical area is the vertical stabilizer attach point. If you remove the stinger, you can take a close look at the bottom of the vertical spar. It is very common to see a crack in the wood below the lower bolt hole. This is apparently caused by the engine idling while on the ground which causes considerable vibration of the vertical stabilizer. No big problem though, because it can be repaired, and when you install the V-shaped bracket as described in the Mite Site Maintenance Tips, it becomes a permanent fix.

Check the interface between the wood (aft section) and the steel tubing (forward section) of the fuselage. This can be done by lifting up on the tail skid. If there is any play at all, the airplane should be grounded until fixed. Also, water will sometimes make its way through any screw holes in the fairing between the fuselage and the wing upper surface and cause you-know-what.

Another area to look at is the landing gear. Mooney used a lot of steel bushings, and they are designed to be sacrificial, so that when you replace the bushing and the bolt, you are back in business. Of course those bushings are not available any more, but you can fabricate your own on a lathe. They are all made of 4130 steel tubing, and, in some cases, off-the-shelf tubing will fit. You usually replace one or two of them when time comes for an annual.

Otherwise, the plane is very strong, The wing, being a one piece structure, is probably the strongest part of the airplane if it is good shape. Note that the plane is not certified for aerobatics, and you wouldn't want to try it. It is just a simple no-nonsense plane that is a delight to fly.

A word about glue: The plane was built 50 years ago, and the new glues such as Resorcinol are a lot better than what was used in those days. Our preference is T-88 from the Shell Oil company. It is easy to use, and has a lot of advantages over the old glues. We were told the only reason that it is not approved for airplanes is that Shell did not want to go through an extensive FAA certification process since the potential market was somewhat limited.

About annual inspections: the Mite is a simple airplane, and annuals are no big deal. For assistance, take a look at Tony Terrigno's annual checklist (pdf file).

Finally, we suggest that you keep the plane clean, dry, lubricated, and fly it regularly.

Thanks to Ben Favrholdt, N66MX, and Gil Gilbert, N4121, for additional comments.

19 January 2002