The craziness continues!
My continuing flirtation with Aviation:
I've purchased a 90% complete Mitchell U-2 Flying Wing!
(Which in Aviation math usually means, 90% is left to be done.)
Repairing the Outer Wing
The first order of business was to inspect and start the repairs on the section of wing damaged by running over a runway light.
|Here is better picture of
the plane in it's new home.
We had some visitors today so before going to work on the plane, we unfolded one wing and put a wingtip rudder in place to give them a feel for how large the wing is.
Total Span = 34 feet.
|Working at home in the garage, I started with the outer wing section which hit the runway light. We initially cut out a small section to see where the ribs where located and then marked the area of skin to be cut out.|
|I removed the fabric and enlarged the damaged areas enough to inspect the leading edge and spar. Good news- neither look to have been damaged. But we found that we would need to cut away more of the skin to get at another damaged rib on the left.|
|Inspecting the damaged
We found mouse turds in the areas between the ribs in front of the spar. If you shake the wing section you can hear something rattling behind the spar - I am afraid that it might be a mummified mouse in my wing - disgusting!
So I'm considering stripping enough of the fabric to find the source of that rattle. That will be another discussion with my local Aircraft Inspector.
|Since we first picked the
plane up in Oklahoma we were aware of the "rattle" behind the
spar in this wing section.
As my local Inspector suggested, I installed this standard inspection hole in the bottom of the wing and found some nesting material, turds and a piece from a foam rib. That rib is not even on the drawings - it is an unnecessary "extra" added by the builder. So the rattle was a false alarm and disappointingly there is no mummified mouse to fly with me!
|This rib wasn't damaged in wreck but removing the skin peeled away some of it's surface so it will have to be "repaired" also.|
|I cut down the three ribs that needed to be repaired. The ribs were made according to the plans from 1# / ft^3 density white foam but I don't have a source for that material so I used the 2# / ft^3 blue foam.|
|The 3 roughed out
rib sections are checked out before being epoxied into place.
|Epoxing the roughed out ribs sections in place. The black lead weights are Norm's.|
|Norm doing some final sanding to finish shaping the new rib sections.|
|The repaired ribs - sanded to shape along with the new doublers at the LE and Spar.|
|Here is a shot of Norm's great design for a wooden clamp to hold the lateral doublers in place while the epoxy cures. We used pieces of torn-up business cards to shim them up tight.|
|Finally I soaked the 1mm
plywood and bent it into shape. After it was dry, it was epoxied
into place and held overnight under slight pressure until cured.
Before closing up the patch, all new wood surfaces on the inside were sealed with a brushing of T-88 epoxy.
|The next steps were to fill any voids along the butt joints and to touch up two low spots; one at the LE and one caused by a rear rib gusset at the spare - the fill work can be seen in the next picture.|
|The paint has been
stripped, the cosmetic fills have been made and the wing panel is ready
for inspection by an expert before starting the covering and painting
(Three weeks to this point since the purchase!)
|Here's a small sign of
progress; today we hauled the wing section out to the field and attached
it to the rest of the plane.
While I had the trailer headed to the field I threw on a table to add to my growing collection of tools out at the hanger.