Incident Repair

11/09/2008 We've begun the recovery process. If you haven't read the incident report, check that out here. In the first picture you'll notice that the failed line was not simply under-flared. There were two largish sections of the flare that had fractured off and were still in the nut. I'm not completely sure what this tells me, certainly the there could have been too much flare pressure used, making the flare too thin. The factory tells me that they have seen failures like this when the nut is over-tightened. That is also possible, because we had been getting some weeping from this line and just snugged it down tighter. In any event, with the high pressure (the factory also tells me that some folks are foregoing the 3003 for some 5xxx series tubing) and the vibration, I've elected to go with hose from Aero based on the recommendation of Gene at Magnum.

Pieces of the fractured flare removed from nut

To recap the damage, the pencil line shows the approximate delamination line. The factory-recommended technique works pretty well, just to take a quarter or bolt and tap lightly on the skin. If it's good, it will make a reassuring thud sound, if it is delaminated it'll sound like an egg shell being cracked to make scrambled eggs. Yea, I know, not a good sound. But, net, we were taking the foam back to the spar based on the factory's recommendation anyway, to this was mainly in play side-to-side (the aft delamination stopped abruptly at the spar anyway). So, the factory recommended taking out the damaged foam and skin, then removing the paint within about 2" of the damaged area, feathering it slightly. Then do the following layups, and maybe feather these slightly to make the following fill work easier. First we'll do 2 layers of Unidirectional cloth at right angles, 45 degrees from the span, and then 1 or 2 layers lengthwise down the span of the wing. This area of the wing is not structural, they just want enough cloth there that the surface isn't damaged by folks leaning on it or whatever.

Wing damage from reflector pole

We have worked the top skin off carefully here, and have started to sand down to the spar. Note that the bulk of the foam is in good shape, it was just skin delamination. Also note the wires in the gapping hole. These are the coax to the winglet com antenna and the 3 sets of wires to damaged stobe light. All of these wires were fine, thankfully, so we just carefully worked around them, and then sawed the foam out with a hacksaw.

Delaminated skin removed

Ready to go Flying?

Damaged foam core removed

12/02/2008 So, we're back in the shop, having finally gotten all of the needed parts, and through the Thanksgiving day holiday. Here you can see that we have recieved the outer two leading edge wing cores from Velocity. We first cut the outer core close to the damaged line, and worked it back to match the wing with a piece of sandpaper (quickly pulled between the two parts) to get a nice join line. Once those matched up pretty closely, we cut the middle core to approximate length and started doing the same with it until it matched, and then worked the inner edge down until the two cores would just fit into the opening. I have to say, I'm nicely surprised at what a nice fit we've managed. Thanks go to my shop buddies Jerry and Bobby.

Cleaned up outer wing section

Cleaned up inner wing section

Wing Cores Fitted, Tops

Wing Cores Fitted, Tops (2)

Wing Cores Fitted, Bottoms

Wing Cores Fitted, Bottoms (2)

Strobe platform molded piece, fitted

12/06/2008 Today we started setting the new wing cores. We'll finalize the wing repair in steps, we've patched the outboard wing as well, and we'll hard-shell the cores to contour match next, then lay 3 alternating layers of Uni on top, and finally bond the new strobe mount on. Here you can see the outboard repair as well as us buttering the cores and wing/spar with micro. We're using EZ84 here even though it's not required, for strength, but will finish up with the Velocipoxy for contouring. It's coming out quite nice, and we'd probably have it hardshelled tomorrow if I weren't presenting to our EAA chapter meeting (on APRS).

Outboard Wing Repair 1

Outboard Wing Repair 2

Outboard Wing Repair (final) 1

Outboard Wing Repair (final) 2

Buttering Spar

Buttering Cores

Setting Inboard Core 1

Setting Inboard Core 2

Setting Inboard Core 3

Both Cores Set 1

Both Cores Set 2

01/01/2009 Well, I took pretty much the entire holiday break off from plane building. I don't know if it's the cold, or the fact that we wouldn't jump right back into the air after putting things right, but I haven't had a huge sense of urgency. As you'll see below, the repairs are coming along nicely. I think we're going to refinish this whole wing, and spray some good primer and a light coat of white topcoat on the wing before we call it done. That will also likely mean that we'll do the other wing in Jerry's shop while it's cold, and then do some finish work on the fuselage when it warms up some before we see the air again. The primer on Victor Fox has taken a beating this year, and probably ought to be bettr protected, and I still need to learn more about the GRT EIS system. Also, after so long out of the air, we'll probably ask Dave to come back and shake her out, and BFR Elizabeth before we really fly much as a precaution.

Hard-shelling the bottom of the wing

Hard-shelling the top of the wing

Uni layup (3 ply crisscross and spanwise) of the wing

Wing layup peel ply

Wing layup smoothing

01/11/2009 As you'll see, we're trying some new epoxies and fillers for our repairs. On the wingtip, where the strobe repair is coming along, we're using Superfill to fair it in, to good effect. On the wing, we're trying the West system for finishing it out, and will likely use superfil over the top to get a nice smooth finish. Once we get the contour right, we'll start working off the old primer and try to polish up the factory finish of the wing and then paint it.

Wingtip replacement molded part structural-adhesived in place

Wingtip part layup

Wingtip part layup peel-ply

Wingtip part with Superfil smoothing

Rudder cable delamination hard-shelling

Rudder cable delamination layup peel ply

West system filler - odd stuff

02/07/2009 Here you can see the wing damage repair entering it's final stages. As you can see below, we added some superfill on the rudder-cable-delamination repair, as well as a couple of low spots on the main repair, and on the strobe repair and some miscellaneous dips in the skin finish. It's funny what you find once you really start trying to make everything really smooth. For instance, I'd never noticed the "swale" at the strake join line where the wing surface starts to rise rather than be flat, kind of Corsair gull-wing style. My buddy Andy says they all do this. Who knew? You can also see the fill work on the bottom of the wing repair.