William, This is what I did. John --- On Mon, 5/25/09, William Rich <[email protected]> wrote:
From: William Rich <[email protected]> Subject: [ercoupe-tech] Corrosion: Elephant in the Living Room? To: [email protected] Date: Monday, May 25, 2009, 5:45 PM I've searched for a suitable Ercoupe continually for the last 6 weeks and I'm an ace Google researcher. One theme that is leaping out at me is CORROSION. As an unbiased newcomer, I can clearly see corrosion is the proverbial elephant in the Ercoupe living room. This infamous NTSB accident finding speaks volumes:http://www.ntsb. gov/NTSB/ brief.asp? ev_id=20040315X0 0324&key=1The key statement is:"Comparison of the inspection requirements in the Service Bulletins and AD's to the area where the corrosion was present in the accident aircraft revealed that none of the inspection methods would likely have found the corrosion."The response to this blunt warning is varied: some have exercised due diligence and performed invasive evaluations of their airframes, including skin removal, ultrasound, and scraping if required; while others have chosen to focus on the Red Herring aerobatic component of the accident report. The vivid pictures in this well known submission are stunning:http://www.ercoupe. info/?n=Main. HartmutscsectionKey statement:"I found some surface corrosion on all parts where previous primer applications did not reach. Nothing major. It just needs a cleanup and prime and done. Then I found what we all are afraid of, something which looked like corrosion on the inboard spar of the trailing edge on the right side of the center section. It is hard to see, because one has to look through two lightening holes, with the wings detached, And even then you can see just a fraction of the rib."The corrosion in this account almost went undetected except for the due diligence of the owner. Corrosion even went undetected during the refurbishment of G-BKIN:http://www.populara viation.com/ Ercoupe/PhotoGal lery.asp? Page=6Key statement:"Shortly after this photo was taken G-BKIN was shipped to the States to Seattle (Tacoma) rebuilt and flown there for a short time before being scrapped due to corrosion in the center section AD."The airframe was "rebuilt and flown" prior to detection of corrosion requiring scrapping.The important thing I've learned in all this is: SERIOUS CORROSION OFTEN WAS YEARS IN DEVELOPING AND WENT UNDETECTD DURING NUMEROUS ANNUAL INSPECTIONS AND EVEN REFURBISHMENT.I personally will exercise extreme caution in my Ercoupe search and insist on rigorous assurance that a prospective airframe is safe.The Ercoupe is an endearing aviation classic. It has both a trendy retro-modern look and a technical execution that remains competitive in the 21st Century. Unfortunately, it is those virtues that belie it's extreme age and possible hidden weaknesses. In my less than humble opinion, it is likely some operational Ercoupes should not be flying, and for some of those, the price of remediation is unacceptable. These are old airplanes, the numbers are dwindling, and the task of finding a safe and reasonably priced airframe is difficult.
