AIRLINE cabin crew have been warned to move quickly to buckle up during air turbulence after a series of incidents that left flight attendants injured.

The Civil Aviation Safety Authority says about a dozen air turbulence incidents are reported in Australia each year. Many cause injuries to passengers and crew.

It cites several recent incidents that demonstrate how even light to moderate turbulence can cause injury.

These include injuries to two cabin crew thrown to the floor on an Adelaide-Perth Boeing 767 flight; a flight attendant injured when light turbulence caused her to fall backwards on a bench; and two crew thrown to the floor on a Dash-8 while landing in moderate turbulence.

Planes can plunge as much as 300m during turbulence. Often there is little warning.

In the US, about 58 people are injured each year during turbulence because they are not wearing seatbelts, but only four people who had belts fastened have been injured between 1980 and 2003.

"Flight attendant injuries occur at a disproportionately high rate compared to others because flight attendants spend more time in the passenger cabin unseated and, therefore, unbelted," CASA said in its latest flight safety publication.

CASA emphasised the need for effective training and communication between the flight deck and cabin crew, as well as the need to comply with "fasten seat belt" signs.

The regulator said flight attendants should know the location of handholds throughout a plane and how to secure a service cart or galley (kitchen) as quickly as possible.

"While turbulence is normal and happens often, it can be dangerous," it said.

"Its roller-coaster ride can cause passengers and cabin crew who are not wearing their seat belts to be thrown about without warning."