When I graduated HMT-303 to become a Huey/Cobra line mech, me and some buds had OJT over at 367.
While me and another guy were doing a Cobra tranny pull, two of our other buddies were out on the line launching and recovering and so forth.
Anyway, one of the "salty" mechs tells one of our guys (who happened to be a little slow) that they needed to check the "Emergency CRS Radio" (also known as the relief tube

) Supposedly, this Emergency Radio is used when the Aircraft crashes on it's side, to talk to the pilot. Haha.
So one of the mechs hops up into the cockpit, and my buddy crawls underneath the Cobra and they tell him to talk into it.
"Hello? Hello? Check check"
"Nope...we can't hear anything"
"CHECK CHECK"
"No, nothing. Try blowing into it, it must be blocked.
"PFFFFFFFFTTTTT -- Check Check!"
"No, nothing...get your mouth closer to it"
...
LOL - Good times on the flightline.
BTW, I can't recall mechs ever pranking the pilots, but we messed with each other a lot.
One time during a DNT "someone" flipped the switch on the HH-1N from TACAN to VOR. Then that "someone" walked into the avi shop and told them the TACAN wasn't picking up at all.
2 or 3 hours later he walks out to the flightline, cool as a cucumber, sees 3 or 4 AVI bubbas huddled around the TACAN with the whole cabin covered in schematics. (One guy saying "Ok...I guess we need to R&R it), plops down in the cockpit, yells "CLEAR - POWER ON," flips the switch and says "Fixed it."
