Washington plane collision: 'Concerning' 100-foot altimeter error led to deadly US Army Black Hawk helicopter-jet crash, reveals NTSB investigation

The deadly midair collision between a US Army helicopter and a commercial passenger jet that killed 67 people in January may have been caused by faulty altitude readings aboard the military aircraft. This was revealed at an investigative hearing into the crash. The National Transportation Safety Board (NTSB), the US agency tasked with looking into the fatal aircraft crash, held hearings this week, from Wednesday to Friday. It revealed that the Sikorsky Black Hawk helicopter involved in the crash may have been flying lower than its instruments showed at the time of impact—potentially contributing to the tragedy.

‘Concerning’ faulty altimeter readings the cause?

The crash occurred on January 29 just outside Washington, DC, as a Bombardier CRJ700 passenger jet was making its final approach to Reagan National Airport. The jet, operated by a regional subsidiary of American Airlines, had departed from Wichita, Kansas. The Black Hawk, meanwhile, was on a training flight. All 67 people aboard both aircraft were killed. There were no survivors.

The NTSB's investigative hearing, held over three days this week, brought together experts, air traffic controllers, and federal regulators for intense questioning. One shocking detail that emerged from the hearings: a mismatch between two of the helicopter's key instruments—the radar altimeter and the barometric altimeter.

Under the investigation, tests were conducted on three similar Black Hawk Lima models from the same Army battalion. The findings revealed this week showed a significant difference between the altitude indicated by the radar altimeter and the barometric altimeter on the aircraft.

Marie Moler, a lead investigator, explained that tests "showed an 80- to 130-foot (24- to 40-meter) difference in flight". In test environments without full rotor lift, the margin narrowed to 20 to 55 feet.

"Once the helicopter rotors were turning and producing lift and thrust, the altimeter readings lowered significantly and stayed lower throughout the flights," Moler said.

NTSB Chair Jennifer Homendy said the finding is troubling. "A 100-foot difference is significant,” she noted, especially in the airspace where the crash occurred—just over the Potomac River, where helicopters are required to fly below 200 feet (60.96 metres).

"I am concerned. There is a possibility that what the crew saw was very different than what the true altitude was," Homendy added.

The NTSB first flagged the issue in a preliminary report back in February, but the latest findings suggest the altimeter discrepancy wasn't a one-off error. It could be systemic.

Despite no current evidence linking staffing decisions to the crash, President Donald Trump had sought to blame diversity hiring policies in aviation for the tragic midair collision.