CHICAGO—It took a posse of aspiring criminologists to help United Continental Holdings Inc. track down the 10-ton jet bridges causing most of the damage to its arriving planes.

Collegiate interns at the nation’s No. 3 airline by traffic also helped identify a cause of costly rotator cuff tears in some baggage handlers. Troubleshooting those and other findings have helped United’s new data visualization project cut injuries among its 85,000 employees by almost a quarter and damage to its aircraft on the ground by nearly a third...