What's new
Van's Air Force

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

Position/Strobe coverage

A

aerhed

Well Known Member
Okay calling all lighting wizards: Does anyone really know (actual proof), that the RV10's wingtip lighting recesses provide part23 coverage? Also, 91.205 says in big letters: Standard Airworthiness Certificates, but in the verbage it says all U.S. civil registered. Are special A/W's exempted by the heading? Even if your Special's op limits say you'll comply with 91.205? I'm asking because of the same old "legal lights" argument.
 
Part 23 coverage limits do indeed apply to experimental amateur-built aircraft when operated at night.
91.205 applies by way of your operating limitations for night and/or IFR operations.
 
Mel, I thought thats where you get snagged. Operating limitations. Even though 91.205 headlines itself for "Standard A/W". So, that cements that down, what about lighting coverage guys?
 
I'm not sure from your question whether you were asking about regulation applicability or whether the tip lighting provides enough coverage. Mel got the first so I will stab the other. On my -6A, I have external lights that provide full coverage, along with a tail position light. Others have eliminated the tail light by using the combo lights externally on the wingtip. With recessed wingtip lighting, the strobes do not cover the full 360 arc in the horizontal plane so you must use a tail strobe/position light. With that combination, the lights do meet the requirements of the regulations.

As for proof, a three-view and a ruler will show you that the lights do indeed cover all the arcs. There are places very close to the airframe that the strobes are not visible from, but for any reasonable distance from the aircraft, one or more lights will be visible.
 
Last edited:
I put Whelen A600's on the outside of my -10 wing tips,,,,not in the cutouts. I also installed a tail position light.
 
Yeah, I put the external combos on an 8 I built. Specifically, I was wondering about red/green position light coverage when using the RV10 recesses. Do it make all the angles? I haven't come close to deciding on strobes/locations yet.
 
aerhed said:
Okay calling all lighting wizards: Does anyone really know (actual proof), that the RV10's wingtip lighting recesses provide part23 coverage? Also, 91.205 says in big letters: Standard Airworthiness Certificates, but in the verbage it says all U.S. civil registered. Are special A/W's exempted by the heading? Even if your Special's op limits say you'll comply with 91.205? I'm asking because of the same old "legal lights" argument.
Click to expand...

With all RV models using the molded in wing tip recess for nav. / strobe lights, it is intended that a tail nav. / strobe (like the whelen A500) be used to comply with the light coverage requirements (that's why the RV-10 rudder bottom has a blister molded into it for a light unit).
 
aerhed said:
Still no answer to part 2. Mel got part 1.
Click to expand...

I guess I don't understand "part 2".
Your lights must meet 91.205. There are no exemptions.
Part 91.205 is written for "Standard" certificated aircraft. Your operating limitations make it apply to your aircraft for night and/or IFR operations.
 
position or position/strobe?

So if you use the recesses for the wing nav/strobe and use only a position light in the tail, does that mean you are not legal for night/IFR? I guess I thought the position light in the tail gave you the necessary coverage.
 
Mel, I just meant does anyone have coverage proof (measured) of the wingtip recesses. On early RV's a lot of guys just cut out some arbitrary triangle and formed a plexi lens for it. Some I've seen obviously didn't provide angular coverage & some "looked" like it did. The 10 tips "look" like they have pretty good coverage, but has anyone measured?
 
I see. Sorry about that. I didn't understand what you were asking. Us "Old Farts" get nearsighted tunnel vision sometimes.
 
terry_georgia said:
So if you use the recesses for the wing nav/strobe and use only a position light in the tail, does that mean you are not legal for night/IFR? I guess I thought the position light in the tail gave you the necessary coverage.
Click to expand...

Correct. You are not. Anti collision has to be visible all the way around. That's why I mentioned the the use of a Whelen A500 on the rear. It is a combination strobe and white nav light.

aerhed said:
Mel, I just meant does anyone have coverage proof (measured) of the wingtip recesses. On early RV's a lot of guys just cut out some arbitrary triangle and formed a plexi lens for it. Some I've seen obviously didn't provide angular coverage & some "looked" like it did. The 10 tips "look" like they have pretty good coverage, but has anyone measured?
Click to expand...

The design work on the tips (and molds) was specifically done to meet the coverage requirements (120 deg each side of center if I remember correctly). I can't give you a specific # but I am sure that if you use the typical light assemblies (Whelen A600 style) it forces them to be far enough fwd that it easily meets the angle requirement for the nav. lights. The strobe coverage is not even an issue because of the need for also having a tail strobe.
 
IIRC from my Air Law, the wing tip lights must be visible from ahead to 110deg around the side. Without getting my protractor out, it looks like the -10 tips meet that requirement.

That would leave the tail light requiring +/-70deg of the rear. Again, the shroud on the front of the Whelen tail light looks like it meets that requirement - it's certified so it ought to!
 
While this is just one vendor's view, you can see the patterns of the product at the following links:

Wing Position

Tail Position

I'm sure that other vendors have very similar coverages. On the RV, you need to have lights on both the wings and tail to meet the FARs.

bob
 
Sorry, thought I covered it in my original post. There's also a vertical requirement to +/- 75 degrees which is also covered by the design installation. I have not actually measured this on a flying RV-10 but I can place my strobe/position light in place on my wingtip and see that it will provide the required coverage (and then some) measuring from the center of the strobe and position lighting elements. As mentioned above, the tail light, even with the shroud, provides more than adequate coverage for the remaining arc. On my -6A, I can stand at the wingtip and see the position light so it is covering much more than 180 degrees.

These installations exceed the requirements by so much that I don't believe anyone has ever actually bothered measuring the exact limits of coverage. Put another way, I don't believe an RV has been denied certification due to inadequate lighting coverage. Does this satisfactorily answer your question?

Edit: Since Bob beat me to post, I'll add that Whelen has a good summary in their catalog, both of the regulations and installation strategies. I can't speak to the LED systems but I'd bet those diagrams Bob linked are conservative. The Whelen lights provide a lot of coverage because the element protrudes from the mount and is unshrouded; even the shrouds on the position lights don't limit them that much (note that the coverage arcs in regulation apply to the strobes, not the position lights).
 
Last edited:
"The design work on the tips (and molds) was specifically done to meet the coverage requirements (120 deg each side of center if I remember correctly). I can't give you a specific # but I am sure that if you use the typical light assemblies (Whelen A600 style) it forces them to be far enough fwd that it easily meets the angle requirement for the nav. lights. The strobe coverage is not even an issue because of the need for also having a tail strobe.

Scott, thats about exactly the answer I was looking for. Patrick, thanks also. Like I said, they look right and I'm just about to tack on the wings & do tips, so I'm thinkin lights. If I stick strobes in the tips, do I have any other options for rear coverage besides the combo light in the rudder? Can you get away with a belly strobe (streamlined) near the rear, or does it lack upward coverage? Tail blockage, etc.?
 
You must log in or register to reply here.
Back
Top