Investigators are looking into whether the pilots of an American Airlines jet sensed trouble just before a devastating midair crash with a helicopter near Washington, D.C. The regional jet, Flight 5342, was nearing Ronald Reagan National Airport on Wednesday night when it suddenly tilted upward in its final descent.

This unexpected shift in the plane’s angle wasn’t enough to avoid the collision with a military Black Hawk helicopter, which was flying higher than its allowed altitude. The crash occurred between 300 and 350 feet above the ground, where helicopters are typically restricted to just 200 feet in that area.

According to safety officials, the helicopter was on Route 4, a designated flight path, but exceeded its permitted height. This placed it directly in the path of the descending jet, leading to the tragic accident that claimed all lives on both aircraft.

A puzzling detail for investigators is the radar data used by the air traffic controller, which reportedly showed the helicopter at around 200 feet—much lower than its actual position at the time of the crash. Officials are working to verify this data and understand the discrepancy.

“Our job is to figure that out,” said Todd Inman, a member of the National Transportation Safety Board.

This incident marks the deadliest aviation accident in the U.S. in nearly 25 years, raising urgent questions about flight safety and airspace management near busy airports.