Comparison of fixed versus formed aircrews in military transport

Historically, transport crews are formed to fly a brief series of sorties together. But what would be the effect of keeping crews together longer? This research investigates the effect of crewing policies on accident rates. We compare the crew coordination performance of fixed teams that work together indefinitely with that of formed teams that work together for shorter periods. We researched 74 accident investigation records of two jet transport aircraft of the U.S. Air Force over 20-year periods. These aircraft used both fixed and formed crews. The "ineffective crew coordination" accident rates for formed crews were significantly safer (z = 12.5 for one aircraft and 2.1 for another p < 0.05). This may imply that airlines and military commands could enhance flight safety by following a formed crew policy. However, further study is needed to identify more completely the effects of crew policies on sortie effectiveness.