Throwing up after a heavy drinking session, either on the evening or the following morning. Chunderbirds involves a ranking system dependant upon the amount of time thrown up.
Chunderbird private (1-2)
Chunderbird sky officer (3-4)
Chunderbird ground warden (5-6)
Chunderbird brigadier (7-8)
Chunderbird death agent (9-10)
Chunderbird apache warrior (11+)
When about to throw up, or after someone has thrown up. Chunderbirds are GO!