Friday, August 5, 2016

Landing Light Lenses – Instillation Woes

Prior to performing the weight and balance calculations that need to be completed for the airworthiness inspection, every piece of the airplane needs to be installed so accurate measurements can be obtained. One seemingly small task that needed completing was installing the landing light lenses. That small task turned out to take quite a bit of time to get accomplished.

The issue revolved around the W-1223E lens backing strips. Van’s plans call for using double sided tape to stick the backing strips onto the lens then insert the lens into the wing. In order to insert the lens into the opening in the wing the lens needs to be flexed a bit and wedged in behind the leading edge of the wing but in front of the landing light ribs. With all the flexing the backing strips kept popping off. I think the big issue was that I was using the thin double sided tape that looks like Scotch tape … guessing I would have been better served with the thicker foam type double sided tape.

It took quite a while trying different methods to keep the backing strips in place with no real success. Was just about to close up shop to head out and get some of the foam type double sticky tape when an idea came to me that ultimately worked great ... and I can whole heartily recommend it to fellow builders who don’t want to fuss with double sticky tape. I ended up using two lengths of waxed cord (the thin type used for jewelry crafting) looped through the center two holes of the W-1223E backing strips but instead of tying a knot, the waxed cord was twisted a few times so it would hold the strips in position while inserting the lens into the leading edge of the wing.
Because the double sided tape was not working out to hold the backing strips onto the lens, to get the task done waxed cord was looped through the two center holes then twisted a few times. Ultimately this worked out quite well to hold the backing strips in place while the lens was inserted into the cutout in the leading edge of the wing.

After the lens was in an approximate position, the outer two screws were threaded into the nutplates. Once the outer two screws were started, the twists were removed from the wax cords and they were pulled out so the remaining two holes could be secured with screws. The wax cord used was the thinner style found at arts and crafts shops for making jewelry.
With screws in the outer edges of the upper backing strips, the waxed cord was unwrapped and is now ready to pull out. The bottom backing strip is now in position and ready to receive screws in the outer two holes.

After the outer screws are in place and the waxed cord removed, the center two holes on each backing strip received screws to complete the instillation of the lens.
Completed instillation of the landing light lens in the wing … one down one to go.

Gee, this was so much fun … think I will do it again for the additional landing light in the other wing.