The downing of American helicopters by ground fire is not new.

He arrived there a few minutes before the American helicopters did.

It is not clear, thus, whether the American helicopters will fly again.

They are the first American helicopters to be developed under a military contract.

It was the third loss of an American helicopter in about a month.

It was the third crash of an American helicopter this month.

Word had spread that an American helicopter had been shot down west of the city.

Less than a week ago, another American helicopter was shot down in the area.

It is the only known case of friendly artillery fire shooting down an American helicopter during the war.

American helicopters landed in her village when she was 12 years old.