Why a United Airlines Boeing 777 Almost Hit the Pacific Ocean

DALLAS — A Boeing 777-200 taking off from Maui's Kahului Airport (OGG) nearly collided with the ocean on December 18, according to The Air Current, which first reported the incident.

At 2:49 p.m., United Airlines (UA) flight 1722 took off for San Francisco, climbed to 2,200 feet, and then descended at a rate of over 8,000 feet per minute. While the pilots were able to recover, they were only 775 feet from the ocean.

Two people familiar with the incident told The Air Current that the climb produced forces on the aircraft and its occupants that were nearly -2.7 times the force of gravity as the steep descent transitioned to an 8,600-foot-per-minute climb.

The entire incident appears to have lasted no more than 45 seconds and occurred in between radio calls with OGG Air Traffic Control.

Causes of the Sudden Decent

The probable causes for such an incident could include pilot error, mechanical malfunctions, or adverse weather conditions. Pilot can misjudge the aircraft's altitude or speed or fail to adjust for changes in wind speed or direction. Mechanical malfunctions can range from engine failure, instrument failure, or other related issues. Adverse weather conditions include strong winds, turbulence, or heavy rain or snow.

At the time of the departure, OGG was experiencing heavy rain, and the incident occurred a day after a Hawaiian Airlines (HA) flight from Phoenix experienced severe turbulence, injuring 25 passengers en route to Honolulu. According to The Air Current, air traffic control tapes show that the FAA's Air Traffic Organization was not aware of the incident in real time.

We've also heard from people familiar with the matter that the UA departure was a Flaps 20 takeoff and that once the Acceleration Height was reached to begin retracting the flaps on time, they were brought up from 20 to UP, skipping completely 15 and 5 by accident while at maximum gross weight and low speed. No official report has yet come out to corroborate such information.

Another issue is that such a steep dive would prompt a call to the aircraft for fear of Unlawful interference (aircraft hijacking) and for monitoring further control of the aircraft, or lack thereof, after the incident. No call was made, and the airline stated that its pilots filed a safety report, but that no report was made to the National Transportation Safety Board due to the lack of injuries or damage to the plane.

The widebody was inspected and cleared before its next flight to Chicago a few hours later. What's your take on the Triple Seven's extreme dive? Be sure to leave your comment on our social media channels.

Featured image: United Airlines Boeing 777-200. Photo: Joao Pedro Santoro/Airways