One of the very brave and highly inspirational women who, during World War 2, flew newly built aircraft from the factories to airfields around the UK. They flew without radios or any armaments. They flew many types of different aircraft with minimal training. Exceptional pilots.
I know, not technically a chopper!!
The T1154 transmitter and the R1155 receiver were the first radios I used to transmit and receive signals (in my teens in the 1960s). These transmitters and receivers were used in Royal Air Force heavy bombers and other aircraft during World War 2. These transmitters and receivers used Morse code and the morse code signal used to ‘chirp’ (sounded a bit like a demented bird on drugs!). Some ‘chirping’ Morse code here.