One STC we have installed several times was developed by a company in Alaska to improve the durability of the horizontal stabilizer on Cessna 206 and 207 airplanes. The stabilizer skins are removed, new skins are installed in a slightly different configuration, and the leading edge skin is held on with screws instead of rivets. This is valuable because, when a plane is operated on unpaved airstrips, stones kicked up by the wheels and propeller blast can beat up the horizontal stabilizer leading edge quite badly.
|Phil works on leading edge attachment. The yellow frame in the picture is a fixture to keep the stabilizer straight while giving good access to it for repair.|
|Josh, a LeTourneau University student on spring break, drives rivets while Phil (standing) bucks the rivets. This swells the aluminum rivet to hold the layers of sheet metal together.|
|Bob bucks a rivet while Phil drives it with the rivet gun. The more skins in place reduces easy access for the bucking bar (a piece of smooth steel). Added concentration is often required to achieve desired results.|
|An FAA Advisory Circular gives guidance.|