Head-slamming turbulence on jetliners eludes easy safety fix

Accidents on U.S. airlines have become increasingly rare except for one category of in-flight mishap that has remained stubbornly prevalent: turbulence that leads to serious injuries.

More than 65% of severe injuries—or 28 of 43—logged by U.S. accident investigators from 2017 through 2020 on airliners resulted from planes encountering bumpy skies, triggered by atmospheric conditions that could be worsening due to climate change.

Because they have to be on their feet far more than passengers, flight attendants are the most vulnerable, according to U.S. National Transportation Safety Board data compiled by Bloomberg News. They’ve been slammed off ceilings, walls and floors, suffering broken vertebrae and other fractured bones as well as head injuries.

“This is a major source of occupational injury,” Sara Nelson, president of the Association of Flight Attendants-CWA union, said in an interview. “Addressing the issues with turbulence has been an issue for us for a long time.”

The NTSB on Tuesday is releasing a safety study identifying trends and a series of recommendations for how the Federal Aviation Administration and air carriers can help prevent them.

The NTSB report comes as evidence is growing that global warming is increasing the risks of jets encountering air turbulence. A 2019 study in the journal Nature found so-called wind shear—sudden changes in wind speed or direction—had increased 15% over the North Atlantic since 1979.

The U.S. skies have enjoyed an unprecedented period of safety for more than a decade. There have been only two U.S. passenger deaths since 2009, a woman on a Southwest Airlines Co. flight on which an engine blew apart and a man on a small turboprop plane in Alaska who was hit by a broken propeller blade.

The industry has essentially wiped out entire categories of crashes, such as those caused by icing and wind-shear.

But turbulence, which can buffet a jet even in clear skies and has proved difficult to accurately predict, has been far tougher to contain.

A Feb. 13, 2019, Delta Air Lines Inc. flight from Orange County, California, to Seattle is typical.

Pilots on the northbound flight, operated by Delta partner Compass Airlines Inc., kept the seatbelt sign illuminated because of an earlier report of “occasional light chop,” but allowed flight attendants to begin serving drinks.

Out of nowhere, the Embraer SA ERJ 175 hit a band of severe turbulence that lasted eight seconds. Two flight attendants were flung into the ceiling and back down to the floor, the NTSB said.

One of the two attendants broke her arm, which constitutes a serious injury under NTSB’s definition. Such injuries also include cases with severe bleeding and a hospital stay two days or longer.

A passenger who had been in the lavatory on the flight also suffered a head wound.

The FAA, which sets safety rules and whose air-traffic controllers guide airline flights, has been working on multiple fronts to reduce the risk, it said in an emailed statement. It’s developing a system to allow pilots to share turbulence reports digitally, for example.

Since many injuries occur at lower altitudes, the government and industry should look at requiring attendants to be seated for longer periods during those conditions, Nelson said.

Increasing communication about existing weather conditions would help, Nelson said. Airlines should improve how they share information with each other and between pilots and flight attendants, she said.

“There needs to be greater emphasis when information changes in the air,” she said.