Thirty-eight people were injured on a United Airlines flight that was headed this week to Washington, D.C., from Lagos, Nigeria, officials in Nigeria said, after the plane experienced what the airline described as “a technical issue and an unexpected aircraft movement.”
Six people were treated at a hospital for their injuries, the Nigerian authorities and the airline said.
United described the injuries to the six people as “minor,” though the Nigerian authorities described them as “serious.” The Nigerian authorities also said 32 others on the flight had minor injuries.
Video and images on social media show the distress and disarray on the plane, with passengers speaking over one another as food and meal trays are strewed throughout the cabin.
United did not offer more details on what it said was a “technical issue” or about the extent of the movement or any potential causes, but said the matter was being investigated.
“We are working with aviation authorities in the U.S. and Nigeria to understand the cause,” the airline said.
The Federal Aviation Administration referred questions to the airline and the authorities in Nigeria.
The flight, which left Nigeria on Thursday night for Washington Dulles International Airport, was forced to return to Lagos for an emergency landing early on Friday. The aircraft, a Boeing 787 Dreamliner, had 245 passengers and 11 crew members on board.
The aircraft was flying over Ivory Coast when it returned to Nigeria, according to information from FlightRadar24, a site that compiles public information about aircraft locations, flight paths and altitude.
The Federal Airports Authority of Nigeria said on social media that four passengers and two crew members sustained serious injuries. An additional 27 passengers and five crew members had minor injuries, the statement said. The nature of the injuries was not disclosed.
“Those with minor injuries received first aid and were discharged immediately, while those with serious injuries were stabilized and transferred to the Duchess Hospital in Ikeja,” which is in the state of Lagos, the authority said. It said the plane did not sustain any major damage.
In an emailed statement on Saturday, a representative for United Airlines said the four passengers and two flight attendants had been discharged from the hospital.
The episode happened about 90 minutes after takeoff, according to data from FlightRadar24, when the jet descended abruptly.
Jeff Guzzetti, a former accident investigator for the Federal Aviation Administration and National Transportation Safety Board, on Saturday noted the similarities between the United flight and an episode in March when a Latam Airlines plane suddenly plunged during a flight to Auckland, New Zealand, injuring dozens of passengers.
“The public may not know for a couple of weeks to a month but the investigators are going to know within a couple of days,” Mr. Guzzetti said of the cause. “They’re going to download the flight data recorder and they’re going to interview the flight crew and also listen to the cockpit voice recorder.”
Anthony Brickhouse, a professor of aerospace safety at Embry-Riddle Aeronautical University in Daytona Beach, Fla., said the episode “highlights the fact that passengers need to stay in their seatbelts as much as possible on aircrafts, even when the captain turns off the seatbelt light.”