The rules for starting work, as told to me by an old and bold WO:
Airmen should arrive by 7.45, ready to start at 08.00.
SNCOs should arrive by 07.55 to ensure the airmen are ready for work.
Warrant Officers should arrive at about 08.20, when any local issues have been sorted by the SNCOs, and the department is running smoothly.
Officers may attend if they wish.