Gilbert Griffith <> writes:

So today I flew the thruster ultralight, armed with Jerry's GPS, and my camera and found the tail, marked it on the GPS from 2500 feet and a lot of photos. I was about 2km off in my estimation from when I lost it!

I came home and printed out a couple of photos then drove out there and walked 3km up the ridge, 70 feet down and back up a gully and the GPS still said half a km further up hill when I stopped to rest. I turned to go uphill again and the tail was right there in front of me at head height five feet away. Such good luck, as I was thinking I wouldn't be able to find it in the thick bushes on the 45 degree slope.

The piece that broke is 145mm long 42mm ID and about 44mm OD tube. The tail stinger slips into it. It only goes 48 mm into the outer sleeve on the keel. About the same as the inner sleeve. There are horizontally opposing holes 20mm from the forward end that take the bolt/pin that I assume holds it in place. There are also two slots in the bottom where I think the flap elastics come out of the keel. The fatigue has started either at the bolt holes or the two slots. Only 95mm sticks out of the keel past the sleeves.

I haven't done a lot of hours on this glider, but it is seven years old or so. It belonged to Davis Straub before I got it and I don't know how many hours it has done. Maybe about 250 if Davis did 100 on it. Maybe this could be a problem for other pilots? I don't know.

John Reynoldson <> writes:

The slots are where the arms of the shackle that holds the rear wires to the keel goes through it, and it's very probable that this is where the fatigue crack started, as it is the weakest point in the area and is under a lot of stress when the glider is parked or put down on its keel. Any crack there would spread quickly. This tube runs all the way forward to the noseplate.

Repair is a bit problematical. I'd probably recommend replacement of the whole lower keel tube. This means drilling out all the rivets in the lower keel though. Not impossible - Steve Norman has done it. The other option is to do some rather creative sleeving.

This is an original ATOS, before the C version. The tail was added later after I went over flying a C version.