The Federal Aviation Administration says it has reviewed an aircraft safety incident from December in which an United Airlines aircraft reportedly descended sharply just after taking off from Hawaii.
According to flight tracking website Flightradar24.com, United flight 1722 departed Kahului, on the island of Maui, normally on 18 December until 71sec after take-off, when the aircraft entered a steep dive. It was tracked as descending from 2,200ft above the Pacific Ocean to just 775ft, before recovering and continuing its flight to San Francisco.
The incident was first reported by The Air Current on 12 February.
Both the FAA and United Airlines are tight-lipped about the event.
“The United Airlines flight crew reported the incident to the FAA as part of a voluntary safety reporting program,” the US aviation regulator said on 13 February. ”The agency reviewed the incident and took appropriate action.”
The FAA did not answer a follow-up query regarding what “appropriate action” was taken.
United Airlines, meantime, says the issue prompted pilot training.
“After landing [in San Francisco], the pilots filed the appropriate safety report,” the Chicago-based carrier says. “United then closely coordinated with the FAA and [pilot union] ALPA on an investigation that ultimately resulted in the pilots receiving additional training.”
United adds that the flight crew members, which have about 25,000h of experience between them, “fully cooperated” with the investigation and are currently in a training programme.
ALPA did not immediately respond to a request for comment.
The United flight was operated in a Boeing 777-200ER registered as N212UA, Flightradar24 says.
The incident was reported just weeks after a similar loss-of-altitude incident by a Qatar Airways Boeing 787 just after it had departed from Doha. On 10 January, Qatar Airways flight 161, bound for Copenhagen, dropped to about 800ft above the ocean before recovering and climbing again.
Of that incident, Flightradar 24 says, ”At points during the 28-second period, the aircraft was descending, it reached vertical rates of more than -3000 feet per minute.”