Posted by Tom Napier on December 19, 2013 at 03:37:35 user Didymus.
In Reply to: Re: GILES Cartoon - ERK posted by Mike Dennis on December 19, 2013 at 23:34:04:
"but origin unknown"
A pure guess based on an allusion on Wikipedia. "Erk" sounds like a contraction/corruption of "aircraftman," the rank's official title.