About 50 U.S. drones of various types have crashed during operation in Iraq and Afghanistan, according to the Christian Science Monitor.
U.S. officials have consistently denied flying spy missions into Iranian air space, though Iranian officials have said since 2005 that they have been monitoring U.S. spy plane missions in their air space.
Drone crashed conveniently close to nuke sites
If the RQ-170 did lose contact with controllers, it crashed a little too close to Iranian nuclear facilities to be a complete coincidence. Iranian radio news reported the drone crashed near the eastern Iranian town of Kashmar, about 140 miles from the border with Afghanistan.
The RQ-170s are based in the southwestern Afghan city of Kandahar and fly missions all across the western part of Afghanistan, but not farther West into Iran, according to a Pentagon spokesperson.
Other U.S. sources told National Journal and NBC News the drone had flown previous missions over Iran, however, using its stealth capability to remain undetected as it shot pictures of Iran's nuclear development sites. The location of the crash in Kashmar is far north of a straight-line course between Kandahar and the cluster of Iranian nuclear facilities near Tehran (BBC map), which is in the country's far north.
A Pentagon spokesperson said there was no indication the drone was brought down by hostile action and repeated that the drone was on a scouting mission over Western Afghanistan; it was not tasked with entry into Iran.