What's new
Van's Air Force

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

Landing Light position

E

ErichKeane

Well Known Member
Hi all-
We are working on our right wing, and bought the light kit at the same time. We ran all of the wires before we installed the skins, and decided to do the landing light before we did the top skins.

I set up the template and center punched all the holes, just to realize that I'd set the template up 1 rib too far in! This makes our decision pretty clear:

1- Trash the skin and start over. This is a ton of drilling (since there is another skin over it!) and a bunch of wasted effort.
2- Live with the light 1 rib in. It should look fine, and I can't think of a reason why it would cause a problem.

At the moment, we're heavily considering the 2nd option. Is there anything anyone can think of that would make #2 a bad idea? I plan on calling Vans tomorrow to ask them.

We'd definitely like to be able to continue, since we are going quite quickly! We started at the beginning of April and intend to get the wings done in the next week or so, and we have our Fuselage being delivered in another week. It would be great not to loose progress over something stupid like this.
 
If you are going E-LSA, you will have to get approval from Van's in writing for the change.
 
Of course Mel is correct since you haven't finished it yet but I do know of people who installed the light kit afterwards that wanted the landing light next to the cockpit. So it doesn't matter to the airplane where you put it but it does matter to your certification, yes.
 
Ok, I suspected there wouldn't be any mechanical issues. I've emailed tech support to ask for the document mentioned. I couldn't get them on the phone all morning, so hopefully they'll be responsive.

We've been extremely careful so far, and did quite well I think. I spend time at work reviewing the plans before we even start a section, so I know just about all I need before I get there. The building really goes quick with 2-3 people at the hangar every night!
 
Peterk said:
Of course Mel is correct since you haven't finished it yet but I do know of people who installed the light kit afterwards that wanted the landing light next to the cockpit. So it doesn't matter to the airplane where you put it but it does matter to your certification, yes.
Click to expand...

It may not matter to the airplane, but it can certainly matter to the strength of the wing structure. It may seem that the wing spar is the only thing that carries any of the wing loads but that is not true. I am not meaning to say that moving the the landing light cut out inboard by one rib bay will cause a problem (it probably wouldn't but I can't say for sure). Moving it all the way to the inboard end of the wing very likely would cause a problem. Not to mention that you would then have the landing light shinning off the back of your propeller (very annoying).
 
Scott is right. The spar is not the only thing that carries wing loading. RVs use a "stressed skin" type of construction. When you start cutting the skins in places that carry loads, you are REALLY experimenting. I wouldn't do it without a complete engineering evaluation.
 
As we were looking at the plans and installing our light (we got it in today!) I think I figured out why it was the most outboard rib. It seems to me that the reason it was placed that far out was so that you could feed the tip-light wire through both of the support ribs and the last rib.

Because we did it with the wing open, we didn't have this problem, so I think we're ok. I understand the stressed skin construction, though the 2nd rib in from the outboard edge doesn't seem like it would cause a problem, particularly since the outboard most rib wasn't designed for the light either.

We took the risk and just installed it as it is, but if we hear otherwise from the factory tech support, I'll let ya know.
 
You must log in or register to reply here.
Back
Top