The American military deaths in helicopter warfare this week in Afghanistan are weighing heavily on Iowa Congressman Leonard Boswell, who served two tours of duty in Vietnam riding in and piloting helicopters. He says it’s very sobering and brings home how intense the fight is when Americans are making the “Supreme Sacrifice.”On Monday, seven U-S soldiers were killed in fighting in Afghanistan when enemy fire hit two Chinook helicopters. The Pentagon says six soldiers were killed when one of the two helicopters crash-landed. Another soldier was killed when he fell out of a copter that was retreating from heavy fire. Boswell says it’s difficult to watch the coverage of the war on terrorism. He says it’s gut wrenching to hear when a crew goes down.Boswell, a democrat from Davis City, says American soldiers “can’t put on your armaments…and load your weapons and go to where there’s fighting going on and not expect there to be conflict.”Boswell was a commanding officer during his second tour in Vietnam. After a 20-year military career, Boswell returned to southwest Iowa to farm, and later entered politics.