US to probe United flight that plunged toward ocean near Hawaii

US authorities have opened an investigation into a United Airlines Holdings Inc. flight that dropped toward the Pacific Ocean shortly after taking off from Hawaii in December.

The National Transportation Safety Board said Tuesday in a tweet that it will formally review the incident, which didn’t result in any injuries. It expects to have a preliminary report ready in two to three weeks.

The United plane took off from Maui on Dec. 18 and climbed normally for about a minute before quickly losing about 1,400 feet (427 meters) of altitude, according to data provided by tracker Flightradar24. The Boeing Co. 777-200ER came within several hundred feet of the ocean before resuming its climb and then flying safely to San Francisco, according to Flightradar24. 

The pilots filed safety reports on the flight after landing, and the carrier coordinated with the Federal Aviation Administration and the Air Line Pilots Association union in investigating the incident, United said in a statement. The pilots, who have a combined 25,000 hours of flying experience, are undergoing additional training as a result, the airline said.

United declined to provide further details, and the union declined to comment. The December incident was earlier reported by the Air Current.