Brainstorming External Lights Switch Layout

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I’m planning (AeroLED) strobes and position lights, taxi lights in the wingtips, and HID landing lights in the leading edges.  The taxi lights will be the ones to wig-wag.

I’ve set the switch layouts up for flow, both in before-flight and approach-to-landing phases. Let’s look at those:

Before Flight:

  1. Strobes ON before engine start.
  2. Position ON before taxiing.
  3. Taxi lights ON before taxiing.
  4. Landing Lights ON before taking the runway.
  5. Wig Wag taxi lights ON either before takeoff or on climbout (wig wags are primarily for traffic/recognition)

Approach-To-Landing (VMC):

  1. Strobes ON (on the entire flight)
  2. Position ON (on the entire flight)
  3. I’ll turn Taxi, Landing, and Wig Wag lights on prior to entering the terminal area. (No impact to switch placement, they can all be next to each other.)

Approach-To-Landing (IMC):

  1. Strobes OFF (because we’re in the clouds and they reflect off the clouds and distract)
  2. Position ON (on the entire flight, even in the clouds)
  3. I’ll turn Strobes, Taxi, and Landing  lights after breaking out of the clouds.
I won’t really need Wig Wag on an IFR flight plan if I’m breaking out of the clouds on an approach, but it couldn’t hurt, and it’s easy to just turn on ALL of the external lights once I’ve broken out.

So, my two choices are a 5-switch setup and a 4-switch setup.

5-switch setup.

This is great for EVERY flight’s checklist flow from Master ON to climbout.

Given that my taxi lights are going to be the ones wig-wagging, I’m nervous about hooking up wig-wag downstream of the taxi light switch (taxi must be on for wig wag to work.)

For example, let’s look at cruise flight. I want to wig-wag for a traffic call just received from ATC. I don’t want to have to flip on the taxi lights, then jump over to the wig wag switch (if wig-wag was wired downstream of the taxi switch). I just want one switch throw. This means if I go with the 5 switch setup I’ll probably wire the wig-wag switch in parallel to the taxi light switch. (Wig-wag will operate regardless of taxi light switch position). That means I get flashing lights with one switch throw.

Seems reasonable, but I also like combining switches where it makes sense.

4-switch setup.

In this case, I’d have to be careful to only go halfway with the switch (which everyone overshoots with 3 position switches, especially in turbulence) for taxi lights only and I’ll have to jump back to the taxi light switch to WIGWAG either before takeoff or on climbout. (I don’t like jumping back over, but I may be able to live with it given the panel space I might be saving.)

If I get an ATC call for traffic while in cruise, I would only need one switch flick; all the way up to wig-wag.

This saves space and a switch, but I don’t really like the vertical TAXI indication and the jumping around during the before takeoff flow.

I think while typing this that I’ve talked myself into the separate function wig-wag switch. Takes more panel space, but I’ve got it already planned there. It may be a little confusing having the taxi lights controlled from two separated switches, but I think pilots only care about the function. Either Taxi, Landing, or Wig Wag. Turn on what you want.

I’ll keep thinking about it, but I think I’m going to go with the 5-switch setup.

(My HID landing lights are showing up soon, hopefully I’ll have a nice post on operation, brightness, and electrical requirements. Stay tuned.)

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4 Responses to Brainstorming External Lights Switch Layout

  1. Bob Vosburgh says:


    Not a wiring pro, however… couldn’t you go to a five switch and have taxi as one and taxi+wig wag as another?


  2. Andrew says:

    I could, but I’m starting to lean toward having a single switch for each independent function. The pilot (me) shouldn’t care that the wig-wag lights happen to also be the taxi lights. If I want wig-wag, I’ll turn on the wig wag switch. If I want landing, I’ll turn on the landing lights.

    Have you thought about what you are going to do for external lighting?

  3. Chris Breet says:

    Hi Andrew,

    Greetings from South Africa! I’ve been lurking for a while now (I am really enjoying your site and learning a lot – I’m planning a RV-7 build in the future too), but this is the first topic that I thought I could potentially add some value.

    First a question:
    1) I assume you will have a beacon light and it will be power through the Master Switch (i.e. beacon is “always on”), hence no dedicated switch for the Beacon.

    Now, based on the above assumption (beacon allways on), I would put the sequence as follows (based on a workflow approach):

    1) Position Lights as the 1st switch (from the left). Since they are the ones that will be on for most (if not all of the flight), they should be the 1st switch in the line.

    2) I’ll go for taxi light next. Here is SA, it’s considered bad airmanship (actually, I think it may be the latest regs as well) to taxi or have apron ops with strobes on – they should be turned on only when crossing a runway or when lining up on the active runway. Thus, my taxi light will be on before strobes.

    3) I’ll do Landing Light next, just to “group” it close with the taxi light.

    4) Strobes will be my last switch – since this one might get toggled a bit during the flight, I’ll put it on the end, so it’s easier to find.

    Regarding the wig-wag switch: I’ll also go for a second dedicated switch (if panel space allows). Alternatively, if you’re concered about bumping through the mid position on a 3-way switch (combined taxi and wig-wag), you could have the wig-wag in the middle position – then, if you bump through it, you’ll have full-on taxi lights (such as on a bumpy IFR approach once below the clouds and you want all the light you can get).

    Keep up the good work – and (obvioulsy) the good blogging!


  4. Andrew says:

    Hey Chris. Sorry it took so long for me to get back to you. I love your idea with the Beacon (and strobes further “down the line”), however, my plan right now is to only have strobes.

    Therefore, the Strobes have to be on the whole time per the US regs (unless detrimental to safety, blah blah.).

    For now, I think I’m leaning towards the 5 switches. Let me know what you end up with on your project. Have you started yet?

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