Simplify the following text for a Grade 5 native English-speaking person.
Original: Some of the people who worked in the bunker were from the No. 2 Volunteer Air Observer Corps ( VOAC ) , The Women 's Auxiliary Australian Air Force and a few members of the Royal Australian Air Force and the United States Army Air Forces . Workers worked in the bunker 24 hours a day seven days a week in shifts called `` Flights '' .
Simplified: The bunker was manned at all times in shifts that the Air Force called `` Flights '' .