Airman Mark Vadnais, 28th Aircraft Maintenance Squadron able chief, searches for the correct tool before conducting maintenance on the B-1B Lancer at Ellsworth Air Force Base, S.D., Jan. 21. Airman Vadnais is participating in an on-the-job training course involving 22 academic days, consisting of 108 hours of training, to become a crew chief for the B-1. (U.S. Air Force photo/Senior Airman Anthony Sanchelli)