[SandRat]

Have you read the book about the making of the movie Battle Of Britain?

[Dark Wing]

I have a 1980-ish IEEE book on radar up through 1945, and Louis Brown’s “Technical and Military Imperatives — A Radar History f WW2” but confess that I missed that one.

[Dark Wing]

I appears that bit of information is in a lot of Gyrocopter/autogyro histories, but not _RADAR_ histories.

See:

http://en.wikipedia.org/wiki/Autogyro

http://www.global-gyro.com/Gyrocopter/History

http://militaryanalysis.blogspot.com/2013/02/autogyro.html