What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

duckworks landing light in center instead of outboard portion of the wing?

mill2978

mill2978

Well Known Member
I am in progress with slow build wings and just got my duckworks landing light bracket. When I look at the pictures of other people's finished RV's I see this is almost always installed at the outboard edge of the wing, is there any reason I can't/shouldn't install it closer to the middle?

I tried searching the forum but didn't see much about install location.

thanks

Aaron
 
It's your thing, do what you wanna do!

mill2978 said:
I am in progress with slow build wings and just got my duckworks landing light bracket. When I look at the pictures of other people's finished RV's I see this is almost always installed at the outboard edge of the wing, is there any reason I can't/shouldn't install it closer to the middle?

I tried searching the forum but didn't see much about install location.

thanks

Aaron
Click to expand...

Look for thing that might interfere, I think its smart, but an engineer might have issue with a large non structural hole more inboard in the wing that has a higher load in the middle, than the far outboard wing leading edge.

I aint no engineer, I cant even drive a train :rolleyes:
 
Think future service. It will be much easier to adjust and/or service the light in the future if you can reach in through the end of the wing. You will also need to get wires to the leading edge. Much easier to do outboard.
 
The skin is more highly stressed the further inboard you go. Think of the wing in terms of a lever arm.

At the most outboard bay, where we normally place the landing light, the skin is stressed very little, so we can get away with cutting a big hole in it.

Cutting a big hole like that further inboard might have much more significant implications to the structural strength of the wing.

Personally, I wouldn't even consider bringing it further inboard, for structural reasons. But if you are considering it, I would strongly suggest a call to Van's to get their input.
 
roee said:
The skin is more highly stressed the further inboard you go. Think of the wing in terms of a lever arm.

At the most outboard bay, where we normally place the landing light, the skin is stressed very little, so we can get away with cutting a big hole in it.

Cutting a big hole like that further inboard might have much more significant implications to the structural strength of the wing.

Personally, I wouldn't even consider bringing it further inboard, for structural reasons. But if you are considering it, I would strongly suggest a call to Van's to get their input.
Click to expand...

Thanks all for the explanation, I'll keep it outboard.
 
roee said:
The most important reason? More important than not having a wing fail in flight??? :eek: :rolleyes:
Click to expand...

I have known many to put it in board including the original owner of duckworks. He later moved it outboard. I dont know anyone that had a wing fail with such a small hole in the leading edge. I was involved in the original testing in the beggining and it really shines back into the cockpit when you install them at mid wing. I used to land at a small airport with no lights and having a really good landing light was a must. Mike
 
Michael Seager said:
I have known many to put it in board including the original owner of duckworks. He later moved it outboard. I dont know anyone that had a wing fail with such a small hole in the leading edge. I was involved in the original testing in the beggining and it really shines back into the cockpit when you install them at mid wing. I used to land at a small airport with no lights and having a really good landing light was a must. Mike
Click to expand...

Mike, I believe you about the problem of having light shine into the cockpit. No disagreement there. But I'm concerned that some folks might take what you're saying to mean that structurally, cutting that hole at mid-span is ok. I don't think it is. It is not a "small" hole. It would be a very significantly sized hole in a highly-stressed, safety-critical, structural area. Unless you or someone else that you're aware of have re-tested the wing to the original load limits with this hole cut at mid-span, then I don't think you can assert that it's ok.
 
During the testing of full leading edge fuel tanks for the RV7 wing I had a aeronautical engineer approve a landing light in the middle of the leading edge. This cutout was used to gain access to the fuel tank plumbing. The leading edge full of fuel(Water) and cut out was static tested to 7.7G with no signs of deformation. The tanks were tested to a FAR23 standard. The only issue was the landing gear test which did not fair-well even without the extra fuel on board. Having the light mid span might not be the best place but In my case it was the best solution.
Mick
 
mick said:
During the testing of full leading edge fuel tanks for the RV7 wing I had a aeronautical engineer approve a landing light in the middle of the leading edge. This cutout was used to gain access to the fuel tank plumbing. The leading edge full of fuel(Water) and cut out was static tested to 7.7G with no signs of deformation. The tanks were tested to a FAR23 standard. The only issue was the landing gear test which did not fair-well even without the extra fuel on board. Having the light mid span might not be the best place but In my case it was the best solution.
Mick
Click to expand...

Cool. Thanks for sharing, Mick. Now there's some good info!
 
LOL

Michael Seager said:
I have known many to put it in board including the original owner of duckworks. He later moved it outboard. I dont know anyone that had a wing fail with such a small hole in the leading edge. I was involved in the original testing in the beggining and it really shines back into the cockpit when you install them at mid wing. I used to land at a small airport with no lights and having a really good landing light was a must. Mike[/QUOTE


Like We're going to take advice from a guy that has more RV time than anybody else on the planet, ya right.


Randy
8A
Click to expand...
 
Put mine in 2nd bay from end---both wings. Not good! Trust me, MUCH easier to mount in outermost bay (reach in from end of wing.) drilling, nutplates, mounting, adjusting and maintaince all easier to reach. --Did mine after the last wing skin was rivited on. Lights have plenty of adjustment -I have a 9 tailwheel, and one light is aimed for landing and the other is for taxi.
 
The best location for installation depends if your wings are done or not. I installed mine in the completed wings, and I definitely needed to access from the outboard end of the wing ... thru the furthest rib and the lightening holes. I can't imagine how I could have done it if it were moved inboard.
 
N208ET said:
Michael Seager said:
I have known many to put it in board including the original owner of duckworks. He later moved it outboard. I dont know anyone that had a wing fail with such a small hole in the leading edge. I was involved in the original testing in the beggining and it really shines back into the cockpit when you install them at mid wing. I used to land at a small airport with no lights and having a really good landing light was a must. Mike
Click to expand...


Like We're going to take advice from a guy that has more RV time than anybody else on the planet, ya right.


Randy
8A
Click to expand...

No disrespect intended, but lots of time in type does not make one a structural engineer...
 
Last edited:
your right about that

roee said:
No disrespect intended, but lots of time in type does not make one a structural engineer...
Click to expand...


Non taken. But knowing what I know about Mike and who he communicates with, I'd take his advice to the bank! No offense. Everybody is entitled to his or her opinion. I respectfully bow out here.

Randy
8A
 
I regularly fly, maintain, and inspect a Seager-built RV-6 that is 23 years old - and it is one of the best-constructed RV airframes I have yet seen.
 
You must log in or register to reply here.
Back
Top