United Airlines Flight 235 plunged to within 748 feet (228 meters) of the ocean’s surface shortly after takeoff from Hawaii in December, according to federal investigators’ findings released on Thursday.
After the confusion between the captain and co-pilot, the National Transportation Safety Board concluded in its study that the crew failed to properly manage the plane’s vertical path, airspeed, and nose orientation.
The NTSB reports that after a regular takeoff in heavy rain at Kahului Airport on the island of Maui, the captain instructed the co-pilot, or first officer, to adjust the wing flaps, but the co-pilot heard “15” instead of “five.”
The pilots quickly became aware of the plane’s downward pitch and accelerating speed.
“At this point, I knew the captain was having difficulty with airspeed control … I couldn’t be certain what the captain was dealing with,” the co-pilot later told investigators.
The plane’s nose continued to pitch down, and the co-pilot saw through the windshield that they were breaking through the cloud cover.
“I instantly recognized the severity of our situation,” he said. “I announced, ‘Pull up, pull up, pull up, pull up’ many times.” The plane’s ground proximity warning system sounded an alarm too.
According to the NTSB, the pilots of the Boeing 777 dropped more than 1,400 feet (427 meters) from a height of more than 2,200 feet (670 meters) into the Pacific Ocean before they were able to regain control of the plane.
The captain said he decided to continue on to San Francisco after the chief flight attendant told him that “everyone was OK” and there was no apparent damage to the plane.
The rest of the trip was routine.
There were 271 passengers and 10 crew members on board.
The 55-year-old captain had nearly 20,000 hours of flying experience, a considerable amount.
The co-pilot’s total flight time was 5,300 hours.
The airline confirmed that both pilots are still employed by United.
“There’s nothing more important than the safety of our crew and customers, which is why we’re drawing on the lessons learned from this flight to inform the training of all United pilots,” said United spokesman Joshua Freed. “Our pilots voluntarily reported this event and United fully cooperated with the independent investigation” to improve safety for the entire industry.
United pilots voluntarily reported the event through the FAA’s safety reporting program, the agency said earlier this year.
The FAA stated that it has investigated the matter “and took appropriate action.”
The incident received no attention until an aviation magazine, The Air Current, published on its investigation into the plane’s data.
Due to a two-month delay in notification, the NTSB was unable to retrieve any data from the plane’s “black boxes.”
On the same day as the United flight, a Hawaiian Airlines flight from Phoenix met strong turbulence as it neared Honolulu, injuring 36 individuals, 11 of whom were critically injured.
Thunderstorms and turbulence were predicted by the National Weather Service, so they issued a warning.