Iran Air Flight 655 was a scheduled passenger flight from Tehran to Dubai via Bandar Abbas that was shot down on 3July 1988 by two SM-2MR surface-to-air missiles fired by , a guided-missile cruiser of the United States Navy. The missiles hit the aircraft, an Airbus A300, while it was flying its usual route over Iran's territorial waters in the Persian Gulf, shortly after the flight departed its stopover location, Bandar Abbas International Airport. All 290 people on board were killed. The attack occurred during the Iran–Iraq War, which had been continuing for nearly eight years. Vincennes had entered Iranian territorial waters after one of its helicopters drew warning fire from Iranian speedboats operating within Iranian territorial limits.
The reason for the downing has been disputed between the governments of the two countries. According to the United States, the Vincennes crew had incorrectly identified the Airbus as an attacking F-14 Tomcat, a U.S.-made jet fighter that had been part of the Iranian Air Force inventory since the 1970s. While the F-14s had been supplied to Iran in an air-to-air configuration, the Vincennes crew had been briefed that the Iranian F-14s were equipped with air-to-ground ordnance. The U.S. military asserts that the Vincennes had made ten attempts to contact the aircraft both on military and civilian frequencies but received no response. According to Iran, the cruiser negligently shot down the aircraft, which was transmitting IFF squawks in Mode III, a signal that identified it as a civilian aircraft, and not Mode II as used by Iranian military aircraft. The event generated a great deal of criticism of the United States. Some analysts blamed the captain of Vincennes, William C. Rogers III, for overly aggressive behavior in a tense and dangerous environment. In the days immediately following the incident, President Ronald Reagan issued a written diplomatic note to the Iranian government, expressing deep regret. When Reagan was directly asked if he considered the statement an apology, he replied, "Yes." However, the U.S. continued to insist that Vincennes was acting in "self-defense".
In 1996, during the Clinton Administration, the governments of the U.S. and Iran reached a settlement at the International Court of Justice, which included the statement "...the United States recognized the aerial incident of 3July 1988 as a terrible human tragedy and expressed deep regret over the loss of lives caused by the incident..." As part of the settlement, even though the U.S. government did not admit legal liability or formally apologize to Iran, it agreed to pay US$61.8 million on an ex gratia basis in compensation to the families of the Iranian victims. The shootdown was the deadliest aviation disaster involving an Airbus A300 as well as the deadliest aviation disaster in 1988. It was also the deadliest airliner shootdown incident until 2014 when Malaysia Airlines Flight 17 was shot down over Ukraine.
Background
In 1984, the war between Iraq and Iran had expanded to include air attacks against oil tankers and merchant shipping of neighboring countries, some of whom were providing aid to Iraq by shipping Iraqi oil. The Flight 655 incident occurred a year after the USS Stark incident, during which the Iraqi Air Force attacked the U.S. Navy guided missile frigate on 17 May 1987, killing 37 American sailors. U.S. naval forces had also exchanged gunfire with Iranian gunboats in late 1987, and the guided missile frigate had struck an Iranian sea mine in April 1988. Two months before the incident, the U.S. had engaged in Operation Praying Mantis, resulting in the sinkings of the Iranian frigate Sahand, the Iranian fast attack craft Joshan, and three Iranian speedboats. Also, the Iranian frigate Sabalan was crippled, two Iranian platforms were destroyed, and an Iranian fighter was damaged. A total of at least 56 Iranian crew were killed, while the U.S. suffered the loss of only one helicopter, which crashed apparently by accident, killing its two pilots. Tensions were high in the Strait of Hormuz at the time of the incident with Flight 655.
In response to the pattern of attacks on shipping, the U.S. Joint Chiefs of Staff issued a NOTAM on 8September 1987, warning all Persian Gulf countries that civilian aircraft must monitor the 121.5 MHz VHF International Air Distress or the 243.0 MHz UHF Military Air Distress frequencies and be prepared to identify themselves to U.S. Navy ships and state their intentions.