As a result of growing tensions from Wednesday's downing of a U.S. military surveillance drone off the coast of Iran, the FAA issued an emergency order this morning prohibiting operations by all U.S. civil aircraft in the Tehran Flight Information Region (TFIR). The order creates a no-fly zone "until further notice due to heightened military activities and increased political tensions in the region, which present an inadvertent risk to U.S. civil aviation operations and potential for miscalculation or misidentification."

The unarmed reconnaissance RQ-4A Global Hawk was flying over the Straits of Hormuz when it was taken down by a surface to air missile (SAM) fired from within Iran. Iran’s account of the incident differs from that of the U.S., which said the UAV was over international waters. Iran claims it was within its airspace.

In a notice issued yesterday, aviation safety organization OpsGroup conceded the region has “always been an area of high military activity,” but warned that recently amplified diplomatic conflict between Iran and the U.S. dictate that the missile attack “crosses a threshold” and “aircraft operators overflying or using airports like Dubai, Abu Dhabi, Ras Al Khaimah, Muscat, and Fujairah” should take particular warning, citing the danger of misidentification, as well as intentional attacks.

Besides the dangers of aircraft misidentification, OpsGroup warned, "The missile system used by Iran was a domestically-built Raad anti-aircraft system, similar to the Russian Buk that was used [to bring down Malaysian Airlines Flight] MH17 [over Ukraine]. Any error in that system could cause it to find another target nearby—another reason not to be anywhere near this part of the Straits of Hormuz."

OpsGroup strongly recommends that operators monitor 121.5 whenever close to Iranian airspace, as Iranian ATC “will transmit on guard with [an] unidentified aircraft coordinates, altitude, squawk, direction of travel and then ask this aircraft to identify themselves as they are approaching Iranian ADIZ [air defense identification zone].”

OpsGroup further warned of the possibility of retaliation by the U.S. in the near future.