Recently we had fun with Jon while showing you some of excellent work by one of our associates recreating a complex piece for the Mig21 leading edge at the Cold War Air Museum. This replacement was driven by our concern for finding and treating corrosion in these older aircraft.
Unfortunately, we occasionally find a problem and then have to deal with it. This particular spot was peaking out at us in an earlier post and when we spotted its sign, we opened up the leading edge of the wing to thoroughly inspect the area. The surface corrosion has been removed in the picture above, so we can see the effect on the remaining metal. This spot is in a short section that joins the leading edge spar of the right wing to the fuselage. While the majority of the metal remains, once the metal structure is corrupted its failure strength becomes an unknown. The safest thing to do is to replace it and that is what our airframe adviser recommended.
Fortunately,part of our critical support system includes access to an excellent aircraft repairman.
Charles is shown here drilling out rivets so the damaged piece can be removed.
The offending piece is shown above, on top of the wing section from which it was removed. Below, it is shown with the replacement piece made by Richard,
After test fitting with the wing mated to its attach points, the piece was given a surface treatment and rivited in place.
After a final coat of paint for additional surface protection, all fittings will be reattached and the wiring harness that ran through the part will be reattached.