Frequently Asked Questions

Round light FAQs


What wire size/gauge should I use?
Generally speaking the 55w will draw 5 amps, the 100w 9 amps and the HID 3-4 amps. To enable a possible future upgrade to 100w bulbs (from a 55W installation), or for an HID initial installation, we recommend a 10 amp fuse/breaker per light and 14 gauge wire. Since the HID lamps have a fast, large initial current draw, the larger 14 guage wire will help at start-up.


What kind of bulbs do they use?
Duckworks Leading Edge Landing lights use an automotive driving light reflector and are supplied with a 55 watt GE H3 type bulb. These bulbs can be purchased for under $10 in 55 or 100w sizes. Stores like Ace Hardware, Checker, Schucks, NAPA, etc., will carry them.


How do I replace the bulbs?
Remove the screws from the lense, slide the lense to the outboard rib, then slide the lense out of the hole in the wing. You may have to squeeze the lense some to get it out. Note that some installers don't trim enough excess off of the lense and this can make removal difficult.


My lens won't go in or out when the mount is installed.
Usually when this occurs it is due to not quite trimming enough material off of the lens. This makes it long enough to hit the mount while sliding it in through the wing cutout. Try rounding the corners off of the bottom of the lens a little more, or if necessary, trim a little more of the excess off. You 'can' trim the plexi off all the way up to the nutplate strip, and within 3/8" of the opening on the sides. However, I would leave 'a little' more than that, in case you need to smooth the edges more.


The double-sided tape doesn't hold the lens nutplate strips in tight enough.
While it doesn't hold real well, once you have installed the lense for awhile, it will hold better. Also, you shouldn't have to remove the lense very often, normally the bulbs last for years. Some builders have used ProSeal to hold them on, which should work well.


How do I aim my Landing Lights?
A good initial aiming is to loosen the 4 screws on the Main Mounting Plate, rotate the top of the MMP back and the bottom forward, all the way until the holes stop against the screws. Putting the Plate in this position will be a good starting point. Further adjustments/tuning can be done once you have flown your RV and seen where the lights hit on approach. Remember, you need to see the runway on takeoff (tail-up in taildraggers usually) and on approach. You may lose sight of the runway during the few seconds of flare, but normally your sight line is down the runway, not at the wing. Adjust the lights to fit your preference in these areas. To make smaller adjustments, park the plane 15-20 feet from a smooth wall/hangar. Turn on the lights and mark the outline of the primary beam on the wall with tape. Now you can adjust the lights by loosening the MMP screws and observing the relative movement in relation to the tape.


Should I 'flatten' the stiffening ridges on the ribs?
No. While it may seem like a bad idea to have the flat ends of the mount against the 'bumpy' rib, it isn't. You still want the stiffness that the ridges provide for the rib, and the uneven surface tends to hold the mount in place without the need to tighten the screws excessively.


Can I mount the lights inboard from the last bay?
NO. Actually, there are some very good reasons to NOT mount them inboard:
1) It violates the 'D' structure that the wing skin forms forward of the main spar. In extreme load conditions this might weaken the wing, when done inboard. Since there is little bending load at the wing tip, mounting it out there is not a problem.
2) It does not provide as wide a field of view, especially on the ground.
3) It may reduce the 'be seen' effectiveness of the lights when used for traffic awareness.
4) It will cause more glare off of the prop disc in dark background situations. You need to keep light off of the back of the prop at night. Of course, moving them inboard by one bay won't be an issue, should you have a reason to NOT use the last bay (ie wing tip tanks or something).


Do I need a 'flasher' for my Landing Lights?
No. However, having witnessed 2 RVs approach an airport and seeing the one with flashing landing lights WAY before seeing the other with steady lights, I'm convinced that your RV is FAR more visible with flashing landing lights. See our WigWag page for some options in this area.


What are proper techniques for finishing acrylic plastic?
The first step in getting a finished edge is scraping. The back of a hacksaw blade is perfect for scraping. Simply draw the corner of the square edge of the blade along the edge of the acrylic.
A 10 to 12 inch smooth cut file is recommended for filing edges and removing tool marks. File only in one direction. Keep the teeth flat on the surface, but let the file slide at an angle to avoid putting grooves in the work.
If necessary, start with 120 grit sandpaper, used dry. Then switch to a 220 grit paper, dry. Finish with a 400 grit wet/dry paper, used wet. Grits as fine as 600 may be used. Always use a wooden or rubber sanding block. When removing scratches be sure to sand an area larger than the scratch. Sand with a circular motion, and use a light touch and plenty of water with wet/dry papers. Almost any commercial power sander can be used with acrylic. Use light pressure and slower speeds.
Final polishing will give acrylic a high luster. Power-driven buffing tools are recommended without exception. Buffing wheels are available as attachments for electric drills. A good buffing wheel for acrylic consists of layers of 3/16" carbonized felt, or layers of unbleached muslin laid together to form a wheel. Solidly stitched wheels should be avoided. The wheel should reach a surface speed of at least 1200 feet per minute. Speeds of up to 4000 feet per minute are useful for acrylic. Acrylic should be polished using a commercial buffing compound of the type used for silver or brass, or you can use a non- silicone car polish that has no cleaning solvents in it. First, however, tallow should be applied to the wheel as a base for the buffing compound. Just touch the tallow stick to the spinning wheel, and then quickly apply the buffing compound. To polish, move the piece back and forth across the buffing wheel. Be careful not to apply too much pressure. Keep the work constantly moving to prevent heat buildup. Never begin polishing at the edge of the sheet. The wheel could easily catch the top edge and throw the piece across the room or at you.


Round light FAQs

I have a flying RV-3/4/6/7/8/9/10 with Duckworks lights. Can I change to the Round 100w or HID?
Yes. The upgrade is designed to fit into the existing Duckworks Main Mounting Plate. A template to cut a round hole over the existing rectangular hole, a stamped aluminum retainer, the round lamp, and new screws are provided.


Should I return my unused Duckworks Std light to Van’s and order a new round light?
NO. We have priced the Upgrade kits so a Std kit plus an Upgrade is about the same cost. Please do NOT burden the nice folks at Van’s with exchanges. Order the Upgrade from Duckworks directly.


Is the conversion difficult?
Not at all. I was able to convert a std kit installed in my RV-6 to the HID kit in under 45 minutes.


What TYPE of HID Lamp is used?
There are various types of HID lamps.  The D1S and D2S are 2 of the most common, with the D1S being the preferred lamp.  The reason is that D1S lamps have the ‘igniter’ in the lamp base, whereas D2S have the ‘igniter’ in the ballast.  That means that the D2S lamps have a high voltage wire (upwards of 20kV possible!) from the ballast to the lamp that can cause much more ‘noise’ and shock hazard, while the D1S has the high voltage step right at the lamp.  D1S lamps for the HIDs in your plane are preferred to minimize radio interference and high voltage on cables.


I heard that the HID Units have a high ‘Inrush’ current at initial power-up. How much is it?
This is true. The inrush is very short-lived, in the milliseconds range, but can peak between 20-25 Amps. The only issues with this have been when being used with some of the ‘all in one’ power panels and with Flashers not designed for HID. Contact your supplier and they can address this if it is an issue. Otherwise, the ramp is so short that it does not affect normal breakers.


Is any special wiring or switches required for the HID conversion?
Possibly. Some HID units have had startup issues with smaller than 14 guage wire. Your 10 amp breaker and standard switch should be OK.


I have a ‘Wig-Wag’ or other ‘Flasher’ device in my current Landing Light installation. Can I use it with the HID bulbs?
Well, MAYBE.  Originally the answer was ‘no’.  But, since the initial introduction of the HID units in aviation, it has been determined that if done correctly, with the proper voltages and timing, the HID units CAN be Flashed.  This WILL reduce the life of the bulbs, however, the life is still well beyond the TBO for your engine, so it should not be a big consideration.  Make sure that you get a Flashing device specifically designed for use with HID lamps.  See our WigWag page.


My HID lamp is emitting a high-pitched whine. Will this cause noise in my radio or other systems?
No. Some HID lamps do emit an audible sound while they are on. However, testing has proven that it does NOT affect other aircraft systems, and the sound is certainly not audible above the other many noises that a running aircraft makes.


I have a non-Duckworks installation that uses a Standard aircraft round (PAR 36) lamp. Will either of these upgrades apply to me?
Yes. The 100w Halogen or HID round lamp will replace a standard aircraft round lamp. These are good upgrades because they last much longer than aircraft bulbs, therefore can be used more often with greater confidence. The 100w Halogen enclosure with bulb costs roughly the same as the std aircraft lamp, but will last much longer and the bulb is replaceable separately for under $10. The HID costs a great deal more, but puts-out much more light and theoretically lasts the ‘lifetime’ of the aircraft. Please contact Duckworks by email for specific questions about your application. (RMD tip lights and Barnard lights come to mind for this application).


Where do I mount the ‘Power Pack’ (ballast) for the HID lamp?
The unit comes with a pre-made cable that connects the Pack to the Lamp. This cable is long enough to allow mounting on the Main Mounting Plate (if it will fit), on a rib near the light, or even on the spar.


My lens won’t fit with the round lamp installed.
You’re probably right. Due to the thickness of the lamp enclosure, it protrudes from the front of the Main Mounting Plate appx 3/8”. This will interfere with the lens removal/install process. Trim the lense almost completely up to the back of the nutplate strips as shown in this photo.