Identification lights.. how were they used?

[RCB]

I am unsure if this is the proper forum for this or not, so please move it to the correct forum (wasn't sure if it would be proper for the markings forum).

I am aware of the identification lights used on several allied aircraft. How did they operate? Did they stay on when over allied ground? did they blink or were they persistent? When would they be turned on?

I have looked for a while, but always found it to be very generically described.

Thanks for any help.

[Matt308]

Are you talking about navigation lights, or something mission specific?

Navigation light - Wikipedia, the free encyclopedia

Navigation lights likely would only be used over friendly territory and then only in accordance with local airspace operational requirements. The latter would be established based upon numerous parameters that may include proximity of enemy forces, need to maintain visual secrecy (e.g., plane spotting for raid counts), minimization of locating airfield position, etc. Use your imagination and likely there were constraints that were operationally applied that may have just been attributed to expediency.

[RCB]

No, what I am referring to is the Identification lights. Of all the ones I have seen, there were three set into the underside of one of the wings. I have attached a pic of them on a P-51. I always guess from their placement that it was to alert AA gunners that it was a friendly, but not really sure about that. A lot books point them out and have photos of them, but that's all they mention.

[geneh]

Aircraft Recognition Lights – A series of colored lights (White, Red, Green and Amber), were installed on aircraft (see Figure _ TBM-3 Recognition Lights) that were used to recognize friendly aircraft at night. These lights were used in different combinations, or could be used for signaling purposes. They were limited to reliable use during daylight. The control switch-boxes were usually positioned on the right-side in fighter aircraft (see Figure _ P-61), and would be located on the aisle stand on bombers. The White recognition light would be mounted on the upper fuselage of the aircraft and was teardrop shaped and protruded slightly upward. The Red, Green and Amber recognition lights were flush mounted usually on the bottom of the fuselage or on the right wing tip.

The white recognition light was not necessarily used on all aircraft, which can also be evidenced by some recognition light switch boxes not containing the white light switch.

On the P-51 aircraft the three colored lights were located on the underside of the right wing, near the tip. The lights could be used in combination and could be switched to burn steadily or flash code signals with them. When the switches were in the “DOWN” position, the lights burned steady. When in the center position they were in the “OFF” position. When in the “UP” position the lights were operated intermittently, as coded signals by means of the “KEY” switch.

The Navy F6F aircraft had the Recognition Lights switches located on the right hand shelf of the cockpit.

The P-38 Recognition Lights switches were located on the right-hand side of the cockpit, and the red, green and amber lights were located on the bottom of the gondola.

On the B-24 bomber, the white light was located on top of the fuselage usually over the center line of the wing, or as close as practicable. The colored lights were located on the lower surface of the aircraft, along the center line with the colors being red, green and amber, from forward to the rear of the bomber. On the B-25 bomber, the colored lights were located on the underside of the right wing similar to the fighter aircraft. The B-17G pilot’s manual lists the white recognition light as being installed at the forward end of the dorsal fin. The red, green and amber lights were spaced approximately 15 inches apart along the bottom of the fuselage to the rear of the ball turret. The control switches for each light and the keying switch were located on the central control panel.

The recognition light switches were wired directly to the to the aircraft batteries on the TBM-3 Torpedo Bomber.

The F-4U Corsair Navy fighter had the recognition lights on the starboard wing, approximately 24-36 inches from the tip of the wing. The lights were arranged close to the centerline of the wing being mounted so they were perpendicular (inboard to outboard) to the fuselage. On the upper fuselage spine halfway between the tail and the antenna mast was the white recognition light.

The PBY-5A Catalina flying boat had the recognition lights (see figure _) on the starboard wing, approximately 36 inches from the outboard float. The lights were mounted in parallel with the fuselage (leading to trailing edge).

[RCB]

That's excellent information, thank you! I wondered if they could be used for codes and the like.

[Sweb]

Originally Posted by RCB

That's excellent information, thank you! I wondered if they could be used for codes and the like.

These lights were an early method for IFF - Identification, Friend or Foe - which later evolved into the use of a radio transceiver that sent out and received codes. The codes were changed daily. In this sense, all aircraft interrogated each other and advised the pilots if any aircraft operating in a particular area were friendlies or not. The transceivers sent out a code, it was received by another aircraft's transceiver and that transceiver responded with the correct response code. If no response was received then it was understood the other aircraft was a foe. This system is still in use.