Rant and Builder Idea!

[wcalvert]

Just tonight I'm helping a builder do some work on his RV-8 QB fuse. There are 15 #8 screws in the lower forward fuselage area (dwg 74, detail B-B) that come from outside the skin through a doubler, with an AN-960 washer and nut on the inside. Most of them are accessed inside the gear tower ... ! The rant is asking why the assemblers didn't install them while they had a chance ?! There's very limited access through the lightning holes, and since this is a QB, no chance to do mods on the towers to allow better access. Anyway, lots of choice words and scraped arms and dropped washers before we came up with a better way.

The solution was to use a short (12") piece of hinge rod (3/32" or so, just fits inside the #8 nut and washer. Bend it into a smooth quarter circle, about 6" radius. Fish the wire into the hole from the screw side, then put the inside end where it's easy to get at. Drop the washer and nut over the rod, then push the rod back out with your finger tip until it gets to it's resting place, with your helper holding some resistance against your push. Hold it there, pinning the nut and washer in alignment with the hole. Pull the rod out, then replace it with the screw. Turn until started, tighten in up.

This technique saved an unbelievable amount of frustration and got all the screws in place in less than an hour, vice half a day.

I imagine this could be useful anywhere you have one of those blind spots where you can't get both fingers on the washer/nut stack.

Cheers

 

[rv8ch]

Great idea Bill! Imagine if they had done this in the QB factory, you would not have had the opportunity to learn this trick and share it with us!

As an aside, I could be remembering wrong, but I think this was done by the factory on my QB - perhaps something changed, or I got lucky, or your friend got unlucky.

 

[wcalvert]

Other side to go today ... not looking forward to it even now!

 

[Mikeyb]

If you think those screws were awkward wait until you have to install and tighten the landing gear hardware.

I’m pretty sure others have retrofitted the gear tower access covers where you just remove the material between the two bottom holes and add an oval cover with dimpled plate nuts and flat head screws.

 

[rmarshall234]

Nice work

You’ve got the right stuff Bill, to be a working A&P mechanic. It’s that kind of creative problem solving that gets ya through the day, everyday.
Well done.

 

[N804RV]

I did mine about the same way. But, I just used a piece of .032 safety wire. Once you've got the nut and washer trapped with your finger, it just takes a little jiggle to get the screw lined up, and a little turn CW/CCW to get it started. All part of the job. If you think that's tough, try safety wiring a tach-generator on a T-400 twinpac upside down and backwards, standing on a step ladder while the friggin pilots are standing around waiting for you to finish with with "helpful" comments.