Hailstones the size of golf balls left some damaged helicopters out of action for more than three weeks

This article is more than 7 years old

This article is more than 7 years old

A freak hailstorm over one of the biggest Nato airbases in Afghanistan grounded more than 80 helicopters, putting several of them out of action for more than three weeks, it has emerged.

The half-hour storm in late April split rotor blades, cracked windows, ruptured the choppers' metal skin and damaged other parts. The hail was so intense that after an intensive repair programme eight of the choppers were still inoperable more than three weeks later, according to a Nato spokesman.

Videos show hailstones the size of golf balls pelting down on the airbase, which is at the edge of a desert and in summer endures temperatures that can climb above 50C.

The storm killed three Afghans in Kandahar, according to a local military blogger who posted pictures of picnic tables with holes punched through.

Replacement parts for the helicopters, mostly blades, had to be rushed to Kandahar from across Afghanistan, Kuwait and even from the US.

"The sheer number of airframe repairs required after the hailstorm provided five years' worth of experience for the airframe mechanics," Regional Command South, the coalition headquarters based in Kandahar, said in a news release about the repairs.

The damage did not affect troops on the ground, the statement said. "The enemy had no opportunity to take advantage of the impact on our aircraft," said Colonel Allan Pepin, commander of Task Force Falcon, 3rd Combat Aviation Brigade, the unit whose helicopters were hit by the storm.

The size of the fleet in Afghanistan and the frequency of operations means many helicopters and aeroplanes are stationed outside on runway aprons rather than sheltered in hangers.

Freak heavy hailstorms are not unprecedented in the region. Scientists recently said they believed a hailstorm had killed hundreds of pilgrims whose remains were discovered more than a millennium later at India's haunting "skeleton lake".