The National Transportation Safety Board found that miscommunication between United Airlines Flight 1722’s captain and copilot precipitated the aircraft’s plunge of 1,352 feet just one minute after departure from Kahului Airport on its way to San Francisco in 2022.

The NTSB’s aviation investigation final report, released Thursday, says the Boeing 777 lost altitude at 2:51 p.m. Dec. 18 during heavy rain. The aircraft, with 281 aboard, went from 2,100 feet to a mere 748 feet above water before the flight crew recovered from the descent.

A passenger aboard that flight told CNN he heard multiple screams when the plane climbed up, then like a roller coaster took a dramatic, nose-down dive for about eight to 10 seconds before climbing steeply back up.

The NTSB report said the flight crew failed to manage the plane’s vertical flight path, airspeed and pitch attitude after the miscommunication about the wing flaps. The flight crew, however managed to recover and resume a normal profile, and no one reported any injuries, the NTSB said.

According to the report, the NTSB learned of the event two months after the incident and chose to open an investigation. But by that time, the cockpit voice and flight data recorder had expired and was recorded over. So the NTSB had to rely on flight crew statements and other records as sources for information in its investigation.

David Evans, an experienced FAA certified airline transport pilot and flight instructor based in California, told the Honolulu Star-Advertiser that United didn’t notify the NTSB because it wasn’t required since there was no malfunction, no accident, and no serious injury.

He explained that the miscommunication was regarding the speed of the aircraft and flap setting.

The report said the first officer evidently misunderstood the pilot, who said to set the wing flaps to 5 degrees, but he set them to 15 degrees.

“Both pilots recalled hearing the initial warnings from the ground proximity warning system (GPWS) and the first officer recalled announcing “pull up pull up” along with those initial GPWS warnings,” the report said.

Evans said, “In order to make a recovery, they had to point the nose downward and get their speed appropriate so they could make a safe recovery.

“By the time they got that, they got down to 740 feet above water.”

Evans, who has extensive knowledge in training pilots, flight operations and NTSB report analysis, said that positive results came out of the incident.

United Airlines has modified the way it is training pilots to address this occurrence, and has issued an awareness campaign about flight path management at its training center.

As for the miscommunication, Evans said that there are airline protocols for a sterile cockpit, so “the only thing they are doing is talking to each other and to air traffic control and flying the airplane.”