Federal investigators said Thursday that miscommunication between pilots led to a United Airlines plane diving within 748 feet of the ocean’s surface shortly after takeoff from Hawaii in December.
The National Transportation Safety Board said in a final report that the crew failed to manage the plane’s path, airspeed and nose direction after the mix-up between the captain and co-pilot.
After a normal takeoff, the captain asked the co-pilot, or first officer, to reset the wing flaps, but the co-pilot heard “15” instead of “five,” according to the NTSB.
The Boeing 777 climbed above 2,200 feet (670 meters) after taking off from Kahului Airport on the island of Maui, then dropped more than 1,400 feet (427 meters) toward the Pacific Ocean. Both pilots told investigators they heard the plane’s ground proximity warning system call out “Pull up, pull up.”
The pilots were able to recover and resume climbing, then continued on to San Francisco without further incident, according to the report.
No one was injured in the Dec. 18 incident, and United changed part of its pilot training, the NTSB said.
The Federal Aviation Administration, which regulates airlines, said earlier this year that the United pilots reported the incident under a voluntary safety-reporting program. The FAA said it reviewed the incident “and took appropriate action,” and United said the pilots received additional training, but neither the agency nor the airline provided details.
The incident attracted little attention until an aviation publication, The Air Current, reported on its analysis of data gathered from the plane.
It occurred on the same day that 36 people were hurt, 11 of them seriously, when a Hawaiian Airlines flight from Phoenix hit severe turbulence as it approached Honolulu. The National Weather Service had issued an advisory for thunderstorms and unstable air in the area.
This report has been corrected to note that the flight took off from Maui, not Honolulu.