The US Army has grounded about 1,100 helicopters for five days to refocus on safety procedures following a rash of fatal accidents in November.

The “safety stand-down” from 3-7 December grounded aviation units at 11 bases in the continental USA operating a mix of Boeing AH-64 Apaches and CH-47 Chinooks, and Sikorsky UH-60 Black Hawks.

“I have a duty to ensure that we are doing all that we can to prevent loss of life and aviation accidents, and that is why we’re standing down to review our procedures and reaffirm our commitment to operating our aircraft safely and effectively,” says Gen Robert Abrams, commander of US Army Forces Command.

Helicopter crews have already suffered 14 accidents in the nine weeks since the fiscal year began on 1 October, according to Army Safety Center statistics updated on 6 December.

That’s only two fewer accidents than reported in the whole of FY2015 and four fewer than logged during FY2014.

The incidents so far this fiscal year have also been more fatal. Accidents in the two preceding fiscal years caused only two deaths combined. But five Class A accidents reported since 1 October have killed eight soldiers already, the safety statistics show.

“We cannot allow tragedy to pass unacknowledged," Abrams says. "We must do whatever is needed to make certain that our soldiers are training and operating safely."

During the stand-down, the affected aviation units reviewed procedures such as flight pre-briefings and after-action debriefings. The army also will review aircraft co-ordination procedures, flight operations standards, pre-accident planning and aircraft maintenance training.