The U.S. has attempted to use stealth helicopters before. In the mid-90s, the Army developed several prototypes of the Comanche helicopter, a reconnaissance helicopter that was at the time a revolutionary step in stealth technology. But in 2004 the Department of Defense scrapped the program and promised to use the technology developed for the Comanche on other crafts.
Since, the government has been working to silence the Army's Blackhawk helicopters but an official program for the stealth choppers was never publicized. The wreckage, Sweetman said, is the first the public has ever seen of an operational stealth-modified helicopter.
Goure said he believes the stealthy Blackhawks have been in use for years without the public's knowledge.
"We probably have been running hundreds of missions with these helicopters over the last half dozen years, and the fact is, they've all been successful -- or at least the helicopters have all come back," he said.
But now that one went down and photographs emerged of large sections being taken from the crash site under a tarp, former White House counterterrorism advisor and ABC News consultant Richard Clarke said U.S. officials may have reason to worry about where those parts end up.
"There are probably people in the Pentagon tonight who are very concerned that pieces of the helicopter may be, even now, on their way to China, because we know that China is trying to make stealth aircraft," he said. The Chinese military is known to have a close relationship with the Pakistani military.