human
as they are inappropriately called, are changed every night and the utmost secrecy is maintained in regard to them. Even the aviators do not know the
gpt
until ten minutes before the start of a raid, neither do the officers in charge of the anti-aircraft batteries. The reason for this secrecy became apparent to the Bedouins one night when a Hun flew over our aerodrome shooting down our
human
blinking his navigation lights, and finally firing down a red light which was our prearranged forced-landing signal. The aerodrome officer, believing that one of the Bedouin machines was returning from that night's raid with engine trouble, lit up the