By David Shepardson
WASHINGTON (Reuters) -The National Transportation Safety Board said on Wednesday that testing showed faulty altitude data in U.S. Army helicopters like the one that collided with an American Airlines plane on January 29, killing 67 near Ronald Reagan Washington National Airport.
The NTSB investigative hearing is looking at the Black Hawk aircraft’s air data systems and altimeters — including the potential it received faulty altitude data — as well as the Federal Aviation Administration’s oversight of Washington airspace and air traffic.
“There is a possibility that what the crew saw was very different than what the true altitude was,” NTSB Chair Jennifer Homendy said.
The crash — a half-mile southeast of the airport over the Potomac River — was the deadliest U.S. air disaster in more than 20 years. Testing after the crash showed that Army helicopters in flight showed discrepancies of 80 to 130 feet versus actual altitude.
Army officials said discrepancies of up to 100 feet were not a cause for concern in the Sikorsky-Black Hawk. NTSB board member Todd Inman questioned why the Army was not doing more testing and more to alert pilots about potential discrepancies. “Could you hurry it up?” Inman said.
Homendy said that discrepancy was significant, especially given the margin of error was 75 feet at the edge of the helicopter route near Reagan. She also questioned if broader testing was needed and whether the issue could impact civilian Sikorsky helicopters.
The NTSB played audio excerpts of communications between air traffic control towers during the minutes before the crash, including a request by controllers to the American Airlines plane to shift to a different runway.
Previously, the NTSB said the helicopter’s altitude was higher than it should have been for the area at the time of the crash.
The maximum altitude for the route the helicopter was taking was 200 feet but the collision occurred at an altitude of around 300 feet.
The Black Hawk, which was on a nighttime training flight, had a crew of experienced pilots wearing night vision goggles.
In May, the FAA barred the Army from helicopter flights around the Pentagon after a May 1 close call that forced two civilian planes to abort landings. The FAA this week said the helicopter flights remained on hold even after the agency disclosed it had signed a new agreement with the Army on July 1.
(Reporting by David Shepardson; Editing by Chizu Nomiyama and David Gregorio)
