Defense officials are concerned about the withering effect hot engine exhaust has on the tail of the aircraft in the Marine Corps' H-1 program, which is developing upgrades for aging attack and utility helicopters. The problem could delay the program's schedule by four months and cost tens of millions of dollars to fix, said a Pentagon source, who endorsed that approach. Navy spokesman John Milliman confirmed the problem recently led the Navy to temporarily ground its fleet of five H-1...
