US authorities on Friday gave a much-anticipated update on the investigation into a deadly collision between two aircraft late last month, saying that officials were looking into an inconsistency in the data with regard to the height of the helicopter at the time of the crash.
Jennifer Homendy, chairwoman of the National Transportation Safety Board, said officials had the “perishable evidence” needed to continue the investigation into the collision between the American Airlines plane and the US Army Black Hawk helicopter at Ronald Reagan National Airport near Washington that resulted in the deaths of 67 people.
Ms Homendy noted that there seemed to be a discrepancy as to how high the helicopter was flying, with one of the individuals on the flight saying the helicopter was at 300 feet (91 metres), and the other saying 400 feet (121 metres), according to flight data.
“Neither pilot made a comment discussing an altitude discrepancy at this time, we don't know why there was a discrepancy between the two. That's something that the investigative team is analysing,” she told reporters at the media briefing.
She later said the NTSB was looking into the possibility that bad data inside the helicopter may have prompted inaccurate readings from the pilot.
The NTSB chairwoman also said that, contrary to speculation and initial media reports, the crew of the Black Hawk were probably wearing night-vision goggles.
“We believe the helicopter crew was likely wearing night-vision goggles throughout the flight … had they been removed, the crew was required to have a discussion about going unaided, there's no evidence that conversation happened,” she said.
American Airlines flight 5342 from Wichita, Kansas – carrying 60 passengers and four crew – was flying to Ronald Reagan National Airport at an altitude of about 120 metres and travelling at about 220kph when it went down over the Potomac River after colliding with the Black Hawk.
Recovery efforts are still under way along the Potomac, where debris from both aircraft is still being discovered, although at Wednesday's briefing, the NTSB indicated it had enough debris to move forward with the investigation.
“We're going to do a visibility study, too,” said Ms Homendy.
“We will also do a laser scan of the cockpits of the plane and Black Hawk, and we're going to take that information as well as information from examination of the wreckage, different seating positions, different heights, different eye positions, also taking into account night vision goggles. And we're going to do a pretty in-depth visibility study.”
The NTSB had previously been seeking comment from any people who may have witnessed the crash to get a better idea of what might have happened.
Helicopter traffic has been heavily restricted near Reagan National Airport since the deadly crash. Some have suggested keeping those restrictions in place indefinitely.
“It's too early for us to say whether it should be permanent,” Ms Homendy said. “However, that's certainly something that the secretary of the FAA [Federal Aviation Administration] can do on their own.”
