I have a soft spot in my heart for the year 1979, because it was the year that Cessna built the T310R that I've owned and flown for the past 18 years. Actually, 1979 was a very good year for general aviation. Manufacturers like Beech, Cessna, Mooney and Piper were assembling craft at a furious pace, delivering about 17,000 new GA aircraft that year. The industry mood was understandably optimistic. Few foresaw that within a few years, demand for new GA aircraft would dry up almost completely -- due to massive changes to the U.S. tax code coupled with a nasty, double-dip recession -- and production would fall off a cliff (to less than 1,000 new aircraft delivered in 1994).Back in GA's salad days, people bought airplanes much as they did cars. They bought them new, flew them for a few years, then traded them for something bigger, faster or fancier. The aircraft manufacturers designed and built those aircraft in anticipation that they would have a useful life of 10 years or so. At the time, that was not an unreasonable prediction, but it turned out to be terribly wrong. When the production of new airplanes all but stopped in the '80s and '90s, owners had little choice but to keep flying their aircraft build in the '60s and '70s. As a result, the lion's share of airplanes in today's GA fleet are 30 or 40 years old.Corrosion has taken its toll on many of those aircraft. Because the manufacturers didn't expect them to remain in service more than a decade, most didn't do a very thorough job of corrosion-proofing. Look inside the wings or tailcone or under the floorboards of most '60s- and '70s-vintage airplanes and you'll see mostly bare aluminum. Only the relative handful of aircraft that were ordered as floatplanes received internal corrosion-proofing (with zinc chromate primer).The industry has learned from its errors. If you look at the new GA airplanes coming from Cessna, Cirrus, Diamond, Lancair, Mooney or Piper, you'll find the factories are paying a lot more attention to corrosion proofing these aircraft. Most of today's production aircraft will probably last as long as anyone wants to fly them.But that's little consolation to "the rest of us" who own and fly older Spam cans with little or no factory corrosion-proofing. It's up to us to make up for what the manufacturers failed to do 30 or 40 years ago.
This is a companion discussion topic for the original entry at https://www.avweb.com/ownership/the-savvy-aviator-19-thwarting-corrosion