Iraqi air defenses were never underestimated during the 2003 war, and coalition air forces went to great lengths to shut down any widespread use of missiles and guns against coalition aircraft. But the Iraqis had learned much about American SEAD (Suppression of Enemy Air Defenses) methods during the twelve years of low level warfare in the No-Fly Zones. One thing the Iraqis learned well was that U.S. radar detectors and anti-radiation missiles were a lethal combination for any Iraqi radar that switches its power on. So throughout the war, Iraqi radars were rarely turned on. They were attacked anyway, as were any missile launchers caught out in the open. The fiber optic communications system, illegally built over the last few years by Chinese firms, was also attacked, as this system was seen as meant mainly for the air defense system. Iraq fired its anti-aircraft missiles after visually detecting coalition targets, doing so without radar. The thousands of anti-aircraft guns, of course, usually fired without any help from radar. The Iraqis continued, as they had over the last 12 years, to place their missile launchers and guns in residential neighborhoods. These were not often attacked, because most of the coalition smart bombs were dropped from 10,000 feet or higher, beyond the range of most Iraqi anti-aircraft guns. Two helicopters (an AH-64 and a UH-60) and an A-10 were shot down by Iraqi fire. In addition, one British and one American fighter were accidentally shot down by American Patriot anti-aircraft missiles.