When you fly a 60-year old classic airplane that you love dearly, any threat to its continued existence is a very big deal, indeed. Those who are lucky enough to have an Aeronca Champ, C-120, Luscombe, Swift, Navion or any of the rest of that distinguished milieu had instant sympathy for we Ercoupers when Mandatory Service Bulletin 32 (SB 32) arrived in the morning mail recently.
SB 32, sent by the type certificate holder, Univair, was issued following a tragic incident in which the wings departed an Ercoupe while it was being flown aerobatically (looping). To be safe, Univair told us to have the airplane's center section main spar tested Ultrasonically to be certain there is no corrosion inside the rivets that hold it together. The SB was issued in spite of the fact that corrosion doesn't appear to have played much, if any, part in the accident.
Well, gee, the airlines are no strangers to Ultrasonic Testing...neither are expectant mothers, for that matter...but for people who fly small aircraft, this is a strange and frightening suggestion. Conceivably, we could lose our airplanes!! Certainly, it's going to cost a lot of money..and besides, who knows where to find somebody who knows how to do it?
Now, let me say right here that a Mandatory Service Bulletin is mandatory only for those who operate an airplane commercially. It is not an FAA AD, and we all know that. But for some of us, the Bulletin put an itchy "what if?" in the backs of our minds ( we are used to being concerned about corrosion) so we went in search of an inspection service.
John Strope, who does my annuals at his shop, Strope Aircraft Maintenance in Waynesburg, PA, found the right people: TEI Analytical Services, Inc of Washington, PA...just right up the road. Who knew? Their inspector, Rodney Jennings, came down to John's place, where he set up shop and did two Ercoupes in one day; mine and one owned by Tom Horacek of Grafton, WV. Both aircraft were in for the "wings off" annual, anyway, so we got a two for one deal that worked out for everyone.
The following photo essay is here as a service to other aircraft owners who may have been as confused as I was. No fewer than 230 rivets were there to be tested and it takes a couple of hours working in a very small space. Rodney, who is used to working on much larger airplanes, many of them military, laughed when he said, "You know what? This test sucks." To be honest, I'm glad it was him and not me.
Here's the setting. My airplane's on the left, Tom's is up near the hangar door.
Rodney tunes his gear. In this picture, he's taking readings from test samples of varying sizes to calibrate the instrument.
Review.
Tight fit for a big man, but that's where he has to go. Everything, including the side windows, had to come out.
Working conditions. Sorry the floor's so dirty.
Here's a long inside shot. You figure out the perspective.
..rivet by rivet by rivet by..
When you can't reach all of them from inside, you take another approach that's just as tight in its own way. Rodney said he could use a "Lightening Hole Expander."
But here's what we came to see. Beautiful reading. Clean rivet. Happy campers.
The Inspector finishes up..writing and printing out a final report on the spot. It contained a lot of numbers, but the bottom line for both airplanes was: "No cracks or corrosion detected." Whew!!.
Here are some footnotes. John Strope keeps some sample pieces around the shop to show what corrosion means. This piece (not from MY airplane) was damaged by mouse urine. See that hole on the bottom?
In case you need a closer look.
Also, this note for other Ercoupe owners: my airplane, a 415-C built in July of 1946, has wing tanks that are flat against the spar, making it impossible to reach a rivet out at the end..
..Tom's, a 415-C built later that same year, has an indentation in the tank. It was no trouble to reach that last rivet. Go figger.
It was an interesting experience; not one I'd choose voluntarily, but interesting, nonetheless. Let me emphasize that this test is not required..yet..and may never be required if the FAA decides against issuing an AD. Those of us taking the test are hoping the good scores we get will convince the Feds that it isn't necessary. But I must tell you that I do feel a little better knowing that that spar under my seat is in the very best condition it can be.
Since Rodney Jennings was able to do two Ercoupes on the same day, he charged us $550 apiece. Be aware, though, that the airplane had to have the wings off and the interior removed by the time he arrived, and that costs time and money, too..not to mention that, for awhile, your airplane just looks like hell warmed over..
