[skydriver]

On the bottom of the P-38, there looks to be a green, red, and yellow light.

What are these for? I looked in my book on P-38's and did not find the answer.

I tried to insert a picture of this, but could not figure out how to do it. If anyone can also tell me how to insert a picture, that would also be appreciated.

Thanks

[PH-LKK]

I've seen these on the bottoms of some P-51s (near the wingtip) as well. I've also wondered what they are. Communications lights for instances where the radio is inoperative or radio silence has been mandated?

Here's an example pic from Tricatus (though in this instance the colors weren't painted in):

[PH-LKK]

Here's a pic from Tricatus showing the lights on the P-38:

[PH-LKK]

A little searching turned up this snippet of a story:

As I mentioned earlier, Dittaino was near Mount Etna. Our missions started very early in the morning, so we were taking off while it was still dark. In a combat area there were no runway lights on the field and we were not permitted to use our landing lights. We used a flashing beacon at the end of the runway to help us maintain directional control. Since we could not use our navigation lights, the only way we could locate and join our flight leader was for him to flash his identification light located on the underside of the plane. Red Flight Leader used his red light, White Flight Leader used his white light, and Blue Flight Leader used his green light. When there were 12 airplanes taking off at very close intervals and trying to locate their leaders in the dark, it got very exciting. On a 9 September mission later that day, one of my good friends, Lt Frederick B. Messmore of the 71st Squadron, flew into the side of Mt. Etna during the early morning take-off and form-up. There was a red beacon on top of Mt. Etna and I believe my friend mistook the beacon for his flight leader. There was no official explanation for his accident.

It comes from this site.

[Epapazian]

Those are so-called recognition lights, used to help U.S. pilots to identify friendly aircraft. Sometimes they remained on all of the time, but in other cases they blinked in some sort of rotating pattern.

[chascbv]

These are recognition lights (red - amber - green), and they were used for IFF identification. They were particularly useful when returning from a night mission, and airfield personnel were aiming their guns at any potential enemy in the sky. A pre-arranged signal pattern, either static or dynamic, was then flashed by all returning fighters and bombers.