The U.S. Air Force recently announced that it knew what had caused one of its RQ-170 UAVs to crash in Iran two months ago. But the air force would not reveal details, except to say that Iran had nothing to do with the UAV crash landing. The air force did say that because they had figured out what brought the RQ-170 down they were continuing to fly RQ-170s on reconnaissance missions. The air force also revealed that the RQ-170 lost in Iran was being operated by the CIA.
The RQ-170 first showed up in Afghanistan and South Korea two years ago. The U.S. Air Force then admitted that this was a high altitude reconnaissance UAV developed in secret by Lockheed-Martin during the previous decade. It has a 12 meter (40 foot) wingspan. The RQ-170 is believed to be a replacement for some of the U-2s and a supplemental aircraft for the larger Global Hawk (which has a 42 meter wingspan). RQ-170s have been operating over Afghanistan, Pakistan, and Iran for at least a year.
There are many mysteries surrounding the loss of the RQ-170 in Iran. For example, on December 8th Iran displayed what appeared to be an American RQ-170, which they claimed had landed intact in Iran two weeks earlier. Iran claimed they had hijacked the control signals for the RQ-170 and landed it themselves. This seemed highly unlikely but not impossible. Experts on Iranian military technology immediately suspected something else. First, the Iranians are constantly lying about their military exploits, especially when it comes to developing new weapons and technology. This is apparently done mainly for domestic propaganda as satellite photos never show more than a few prototypes of these wonder-weapons.
Then, many Americans familiar with the RQ-170 carefully studied the pictures of the "captured" RQ-170 and immediately suspected something was off. For one thing, the RQ-170 shown was the right size and shape but the wrong color. Not just a different color from that seen on many photos of the RQ-170s in Afghanistan but also a color unknown in American military service. A closer examination of the Iranian RQ-170 photos indicated that the Iranians had reassembled an RQ-170 that had crashed and broken into three or more pieces. Then the Iranians apparently gave the UAV a new paint job (which was obvious to anyone seeing those photos).
At the moment, the only things one can be sure of is that the American operators of the UAV lost the satellite signal connection with the RQ-170 and the aircraft eventually crashed. There was no indication of Iranians jamming the satellite signal. Iran has jammed satellite signals before but only with wide area entertainment programming, not encrypted UAV control signals. Thus many mysteries remain but some have been cleared up because the Iranians could not resist creating a photo opportunity.
Exactly why this UAV came down, and how damaging the loss of aircraft and sensor technology is, won't be known for years. Losses like this have occurred for decades and do have an impact. For example, U.S. cruise missiles that crashed in Pakistan (on their way to Afghanistan) in the 1990s clearly influenced the design of a Pakistani cruise missile. American warplanes that crashed in North Vietnam during the 1960s provided some tech for China and Russia but nothing decisive.