The US FAA is advising airlines to renew efforts to alert passengers of the potential for injury when not wearing seatbelts during turbulence.

An Information for Operators alert, issued on 6 January, is designed to increase public awareness "about the increased risk of injury to passengers and cabin crew members when passengers ignore the seatbelt sign", says the FAA.

The action comes after "three recent turbulence incidents" on air carriers, says the FAA, adding that its flight standards service analysis and information staff recently concluded that turbulence "is the leading cause of in-flight injuries".

Though the incidents are not identified, a search of NTSB incident reports from 2010 show nine turbulence-related reports where passengers and/or cabin crew received injuries.

In one case, 17 passengers and four cabin crew members were injured when a United Airlines Boeing 777 flew through an isolated thunderstorm cell en route from Washington to Los Angeles on 20 July. The aircraft diverted to Denver.

Along with developing scenarios to train crew members for a "quick response" to in-flight turbulence reports, the FAA recommends that carriers develop business card-sized warnings printed with "Turbulence Happens - Click it, don't risk it" to be handed out to passengers "that ignore crew member instructions" to buckle up.

Source: Air Transport Intelligence news