Finnish Radio Intelligence

[Mangrove]

Part of a list of codes quoted by Manninen. Originally supplied to the French by the Finnish Radio Intelligence but later rerouted to the United States.

[Mangrove]

I have not checked this from the records but after the War started in 1941, Finnish Air Force HQ started to receive daily Soviet identification codes for friendly aircrafts. I think these codes were sent and encoded with very simple codes. These were in form of colourful flare combinations and were shot out of the aircraft when an unknown plane was encountered. The codes allowed captured Soviet aircrafts (such as I-153 and PE-2) flown by Finns to fly deep in Soviet territory without being harassed by fighters or anti-aircraft fire.

An example from 17 February 1942

[...] The enemy's friendly identification code for 18 February is two green flares and 3-5 rolls with the wings.

[Juha Tompuri]

This and that more or less topic related in Finnish, Swedish and English:
http://gallery.itexpertti.se/

Regards, Juha