Attaching Wingtip Lenses

Noah · #1 05-02-2009, 08:56 AM

Well after 13 hours of carefully filing the edges of my wingtip lenses so you couldn't fit a hair into the gap with the wingtip (

), I am thinking about attaching these suckers. An internet search reveals that there are predominantly two schools of thought on attaching these - using either 2 fasteners or 6. I am curious as to whether the folks that used only 2 fasteners ever had any issues (like stress cracks around fastener holes, vibration, etc.

I'm also wondering if there are similar issues with direct countersink of the lens, as opposed to using the countersink washers which appear in some of these photos. Are these necessary? Anybody got a P/N? Anybody know what these lenses are made of?

http://www.rudigreyling.com/pictures...p_light_01.jpg
http://www.jeffsrv-7a.com/LEDPROJECT/LED%20090.jpg
http://www.vincesrocket.com/wing%20c...0s%20lens2.jpg

scard · #2 05-02-2009, 09:02 AM

I haven't had any problems with just two screws and countersunk tinnerman washers. 375hrs.

andrew phillips · #3 05-02-2009, 05:21 PM

I have one screw top and bottom in the corners and it holds great. I don't even have the tinnermans...yet. 80+ hrs and no problems. I did bump my lens against the prop of another plane in the hangar while pushing the plane around. The lens popped off and both screw holes were cracked. Needed a new lens. Don't know if I would have had more or less damage with more screws but I do like my set up.

N941WR · #4 05-02-2009, 06:19 PM

Two screws for me and 230 hours.

AllanC · #5 05-03-2009, 05:56 AM

I had 2 CS screws with TM washers in the corners (top and bottom) and it seemed very secure, but this was rejected by my DAR at time of inspection. He wanted me to put in another 4 (2 extra top and bottom) on each side. Did it while he was there, so no delay with pink slip. YMMV

Allan

jthocker · #6 05-03-2009, 07:36 AM

So, lets see, you built it per plans( 2 screws) and the DAR decided he knew better than the designer! Time to find another DAR!

Ironflight · #7 05-03-2009, 08:40 AM

Two screws - 900 hours, no issues!

Paul

Noah · #8 05-03-2009, 11:47 AM

Quote:

Originally Posted by jthocker

So, lets see, you built it per plans( 2 screws) and the DAR decided he knew better than the designer!

Boy, if that's in the plans, I'll be surprised. I've looked everywhere. It certainly isn't on any RV-7 drawings. In fact, I couldn't find any reference from Vans on attaching these. Maybe there's some supplemental instructions that I missed. Anybody got a reference on that?

avi8tor50 · #9 05-03-2009, 02:12 PM

Wondering if, and how folks have sealed between the tip lens and wingtips to prevent water from seeping in.

Peter K
9A