I have 1 1977 Seneca 2 with about 3,500 hours. When I first got the airplane I had the wings treated with ACF-50 corrosion inhibitor. This was a really good idea and ten years later my airplane has almost no corrosion. Almost. During this years annual a little bit of pitting corrosion was found under the rudder mount hinges requiring that the spar under those hinges be replaced. The new spar has arrived and that’s being done now. My mechanic, Nathan, was poking around in the back seating area under the read seats where the seatbelts are anchored to the airframe. I’ve attached a picture of what he found. Ultimately, two aluminum plates are being replaced and this area will be rebuilt with all new, corrosion-free aluminum and will be as good as new. However, if we had missed it for a few more years it would have spread and cost a bundle to repair. I’ve written an article for the Piper Flyer about my experience. In short, don’t delay corrosion no matter what it costs. If you delay the cost will only increase by orders of magnitude and the risk of airframe failure will only increase, too. See my upcoming article on this dreaded subject.
Scott Sherer
N344TB
