I started with the Whelen wing tip lighting, the "Microburst III". There are less expensive choices, but I spent a lot of time in the CT aviation crowd, and learned respect for the Whelen team and products. Worth the $450? I'll find out over the long haul. The sooner you install the lights the sooner the lenses will break. I'm getting all the connections ready, but I won't do final install until I am at the airport. At the wingtip the connectors are DB pins, crimped, with shrink tubing with inner glue used for strain relief. DB pins are rated for 5 amps in low density loads. This load is significantly less than the rating of the DB pin connection. The connections at the wing root are shelled DB connections - there is room for a connector and it is possible the wings will come on and off several times.

The FAR's governing this area were clarified with Advisory Circular 43-217 dated 12/12/2018. At section 11.7.1 the AC says the required light intensity is in 23.2530, which says "Any position and anti-collision lights, if required by part 91 of this chapter, must have the intensities, flash rate, colors, fields of coverage, and other characteristics to provide sufficient time for another aircraft to avoid a collision." The AC also says that Part 23 aircraft certified prior to August 30, 2017 comply with 23.1405, which gives a table for required output measured in "effective candela value". At a measuring distance of 1 meter, the values for candela (lumen per steradian) and lux (lumen per m2) are the same and a candela is to 1 lumen x square meter per steradian. Per the FAR's, the light should put out 400 ECV at the 0 horizon. My non-calibrated light meter shows light output of 421 lux, so I believe I comply with both standards.

Wire sizing From AC43.13-1b: "Wires must be sized so that they: have sufficient mechanical strength to allow for service conditions; do not exceed allowable voltage drop levels; are protected by system circuit protection devices; and meet circuit current carrying requirements." With a nominal 14 volt system the allowable voltage drop is 0.5v continuous, 1v intermittent. As applied to the wingtip lights....... Total amp draw at 14v = nav 0.25 continuous + strobe 0.2 average and 1.2 intermittent. Each wing 14', total single wire run estimated at 16' x round trip = 32'. Fig 11-2 (continuous) says 22 awg handles 1a for 30', so redundant for the nav and average strobe draw. Figure 11-3 (intermittent) says 22 awg will handle intermittant 1.5A in a 40' run, so good for the strobe intermittant. The ground has to handle both loads, so 0.45a average and 1.45 intermittent. I upgraded the shared ground to 18 awg - better safe - and fused the 2 circuits (Nav & Strobe) at 5a each. The old fashioned strobes handled a lot of current and created interference for the com circuits. LED strobes are low current, but still a strobe and run alongside antenna wires. For the wing portion a good twist in the wires, and at the wing root it connects to shielded twisted pair. As a caveat to the tables, I note that Whelan manufactures these lights with 4 leads of AWG 28 or so - those are surprisingly fine wires.

The nose holds landing and taxi lights, a pair of 6-LED lights in aluminum cases which are finned to act as heat shields, with shock resistant design (intended for use on ATV's). I modded the cases for fit in the nose cavity, then attached to the bottom and side ribs with dabs of flox. Connectors are DB pins, crimped, with shrink tubing with inner glue used for strain relief. DB pins are rated for 5 amps in low density loads. This load tests at 0.9 amps at 12.8 significantly less than the rating of the DB pin connection. The wire run is about 3 feet x 2 = 6, so 22 AWG is redundant, fused at 5a.

I made and rejected multiple lenses - 5 in plexi and one in Lexan, before learning how to make a good Lexan lens (heat very slowly, nudging up the oven temperature to a soft slump. The lens was trimmed with bandsaw, then sanded to final profile and attached with silicone. The nose compartment is unventilated and the LED's generate heat. I placed a probe between the lights, sandwiched between the radiator fins. The LED's raised the fin temp from 88F (garage temp) to 120 (15 minutes) and then 141F (30 minutes). The fins were uncomfortably hot to touch. The surrounding composite surfaces were only slightly warmer than the air. With landing and taxi lights typically on for less than 15 minutes and a transition temperature of 165F (50C), I am satisfied that this solution works for this application.

10/18/20 - I came back to the lens and decided it needed a better shape. I rebuilt the base with 2 plies of BID, then a foam micro slurry, then micro. That was sanded flat. I cut the existing lexan lens to have a matching flat, and attached with the flexible and durable "Shoe Goo". See photo. I then faired with a wood flour + epoxy mix.