Iran Air Flight 655 was an international scheduled passenger flight from Tehran to Dubai via Bandar Abbas that was shot down on 3 July 1988 by two surface-to-air missiles fired by USS Vincennes, a United States Navy warship. The missiles hit the Iran Air 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, making it one of the deadliest airliner shootdowns of all time, the deadliest aviation incident involving an Airbus aircraft of any type, and the deadliest aviation incident in Iranian history.
The shootdown occurred during the Iran–Iraq War, which had been ongoing 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, Vincennes's crew misidentified the aircraft as an F-14 Tomcat, a US-made fighter jet part of the Iranian inventory, despite it transmitting civilian identification codes. They assert that Vincennes and other warships repeatedly tried to contact the aircraft on both civilian and military air distress frequencies, but received no response. Bandar Abbas acted as a joint civil/military airport, and Flight 655 had departed behind schedule. The Iranian government maintains that the US recklessly shot down the aircraft, violating international law, after repeatedly provoking the Iranian forces. Some analysts blamed the overly aggressive attitude of Vincennes's captain, William C. Rogers III, while others focused on more widespread issues and miscommunications on board. Despite the downing of the aircraft, Rogers received the Legion of Merit in 1990 for his "outstanding service as commanding officer".
The United States was criticized for the downing, especially in its initial response. Although not issuing a formal apology, US president Ronald Reagan issued a written diplomatic note to Iran, expressing deep regret. In 1996, both governments reached a settlement in the International Court of Justice in which the US agreed to pay US$61.8 million (equivalent to $127 million in 2025) on an ex gratia basis to the families of the victims and two A300B4-600 as compensation for Iran Air. As part of the settlement, the US did not admit liability for the shootdown.
Background
By 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 its oil. In 1987, a year preceding the shootdown, the Iraqi Air Force had attacked the US Navy frigate USS Stark, killing 37 American sailors, after misidentifying it as an Iranian warship. The Stark incident culminated in the widening of the US Navy rules of engagement in the Persian Gulf, allowing warships to attack aircraft before being attacked.
After a US oil tanker struck a mine in the Persian Gulf, additional warships were dispatched to the area; by late 1987, US forces had challenged and launched missiles at two Iranian fighter jets. In April 1988, the US engaged in Operation Praying Mantis in retaliation for mines, bringing significant damage to Iranian oil infrastructure and its military.
In response to the pattern of attacks on shipping, the US Joint Chiefs of Staff issued a 'Notice to Airmen' (NOTAM) on 8 September 1987, warning all Persian Gulf countries that civilian aircraft must monitor the International Air Distress frequencies and be prepared to identify themselves to US Navy ships and state their intentions; Iran disputed the validity and accuracy of these notices.
On the day of the incident, USS Vincennes, alongside USS Sides and USS Elmer Montgomery, had been assigned to take part in an escort traveling through the Strait of Hormuz. Vincennes was a Ticonderoga-class guided-missile cruiser, commissioned four years earlier, fitted with the then-new Aegis Combat System. With a crew of 400, it was under the command of Captain William C. Rogers III at the time of the shootdown. The Aegis system was capable of tracking multiple mobile targets simultaneously, both naval and airborne, and more importantly allowed rapid dissemination of information between different levels of the crew. Its crew was inexperienced in actual conflict, but had performed well in training scenarios.
At its narrowest point, the Strait of Hormuz is 21 nautical miles (39 km; 24 mi) wide. As a result, to traverse the strait, ships must stay within sea lanes that pass through the territorial waters of Iran and Oman. It is normal for ships, including warships, entering or leaving the Persian Gulf to transit Iranian territorial waters. During the Iran–Iraq War the Iranian forces frequently boarded and inspected neutral cargo ships in the Strait of Hormuz in search of contraband destined for Iraq. While legal under international law, these inspections added to the tensions in the area.
Flight and shootdown
The plane, an Airbus A300 (registered as EP-IBU), was under the control of 38-year-old Captain Mohsen Rezaian, a US-educated veteran pilot with 7,000 hours of flight time, including over 2,000 in an Airbus A300. The first officer was 31 years old and the flight engineer was 33 years old. All had at least 2,000 flight hours.
Flight 655 left Bandar Abbas at 10:17 Iran Standard Time (UTC+03:30), 27 minutes after its scheduled departure time due to an immigration issue. It should have been a 28-minute flight. Before takeoff from runway 21, it was directed by the Bandar Abbas tower to turn on its transponder and proceed over the Persian Gulf. The flight was assigned routinely to commercial air corridor Amber 59, a 20-mile-wide (32 km) lane on a direct line to Dubai airport. The short distance made for a simple flight pattern: climb to 14,000 feet (4,300 m), cruise, and descend into Dubai. The airliner was transmitting the correct transponder squawk code typical of a civilian aircraft and maintained radio contact in English with appropriate air traffic control facilities throughout the flight (see § Radio communication).
On the morning of 3 July 1988, Vincennes was passing through the Strait of Hormuz, returning from an oil tanker escort duty. A helicopter deployed from the cruiser reportedly received small arms fire from Iranian patrol vessels as it observed from high altitude. Vincennes moved to engage the vessels, in the course of which both sides violated Omani waters and left after being challenged by a Royal Navy of Oman patrol boat. Vincennes continued to pursue the Iranian gunboats, entering Iranian territorial waters. Two other US Navy ships, Sides and Elmer Montgomery, were nearby.
In the meantime, Flight 655, proceeding along its scheduled route, was on an ascending flight path towards Vincennes. In the time that followed (the details of which are debated, see below), Vincennes incorrectly assumed the aircraft to be hostile and issued 10 challenges to the airliner, seven on the Military Air Distress (MAD) frequency, and three on the International Air Distress (IAD) frequency. Sides additionally made one challenge on the civilian frequency after those of Vincennes. The aircraft was not equipped to receive military transmissions, and the civilian challenges received no responses. Subsequently, the crew of Vincennes commenced the process to engage the aircraft. Flight 655 made its final transmission at 10:24:11 to acknowledge a hand-off from Bandar Abbas approach controllers:
10:24:07 – Bandar Abbas Approach: "Iran Air 655 roger, contact Tehran Control 133.4, have a nice flight."
10:24:11 – IR655: "Thank you, good day."
Eleven seconds later, at 10:24:22, with the aircraft at a range of 10 nautical miles (19 km; 12 mi), Vincennes fired two SM-2MR surface-to-air missiles. The first missile intercepted the airliner at 10:24:43 at a range of 8 nautical miles (15 km; 9.2 mi), and the second missile intercepted the airliner shortly after. The plane exploded, and immediately disintegrated into three pieces (cockpit, wing section, and the tail section) and soon crashed into the water. None of the 290 passengers and crew on board survived. Much of the wreckage, including the cockpit voice recorder and flight data recorder, was never recovered.
At the time the missiles were launched, Vincennes was located at 26°30′47″N 56°00′57″E / 26.51306°N 56.01583°E, placing it within the twelve-nautical-mile (22 km; 14 mi) limit of Iranian territorial seas. The location of Vincennes in Iranian territorial waters at the time of the incident was admitted by the US government in legal briefs and publicly by Chairman of the Joint Chiefs of Staff, Admiral William J. Crowe, on Nightline in 1992.
Radio communication
The official International Civil Aviation Organization (ICAO) report stated that 11 attempts were made to contact Iran Air Flight 655 from Vincennes and Sides, seven on military frequencies and four on commercial frequencies, addressed to an "unidentified Iranian aircraft" and giving its speed as 350 knots (650 km/h; 400 mph), which was the ground speed of the aircraft their radar reported. Flight 655's crew, however, would have seen a speed of 300 knots (560 km/h; 350 mph) on their cockpit instruments, which was their indicated airspeed, possibly leading them to conclude that Vincennes was talking to another aircraft. Both Sides and Vincennes tried contacting Flight 655 on several civilian and military frequencies. The ICAO concluded that Flight 655's crew assumed the three calls they received before the missiles struck must have been directed at an Iranian P-3 Orion, which was also taking off from Bandar Abbas.
The crew likely were monitoring the civilian international air-distress (IAD) frequency at the time of the shootdown. In its report, the ICAO found, according to The New York Times, that "American warships in the Gulf had no equipment that allowed them to monitor civilian air traffic control radio frequencies", and had they had such capabilities air traffic control transmissions would have identified the flight. In its ICJ statement, Iran disputed this by claiming that the Department of Defense's report explicitly mentioned the Vincennes's VHF radio equipment that would have allowed it to monitor civilian air traffic control frequencies, as well as other US surveillance activities in the Persian Gulf region that would have alerted them of the aircraft's nature. The US objected to this claim, saying that most of its military vessels were only equipped with VHR radios capable of listening to the IAD frequency.
Victims
The aircraft was carrying 290 people: 274 passengers and a crew of 16. Of these 290, 254 were Iranian, 13 were Emirati, 10 were Indian, six were Pakistani, six were Yugoslavian, and one was Italian. 65 of the passengers were children.
US government accounts
According to the US government, Flight 655 was first detected immediately after take-off by Vincennes, transmitting IFF mode 3 (civilian). As the flight had originated at Bandar Abbas, which served both as a base for Iranian F-14 Tomcat operations and as a hub for commercial flights, all departing aircraft were by default "assumed hostile". When the identification supervisor responsible, Petty Officer Andrew Anderson, interrogated the aircraft again soon after with his IFF radio, he neglected to reset the range and received a short IFF mode 2 transmission (indicative of a military aircraft), likely from unrelated ground aircraft taking-off at Bandar Abbas. As a result, Flight 655 was erroneously tagged by Anderson with this military classification and squawk code. The mistagged squawk code corresponded to an F-14 that had flown out of Bandar Abbas a week before, leading the crew of Vincennes to believe the airliner was an Iranian fighter jet. For the entirety of its journey Flight 655 solely squawked civilian IFF codes. Due to the flight's slight delay, the dark environment of the Combat Information Center (CIC), and confusion over time zones, Anderson missed Flight 655 in commercial flight listings.
Escalations began when Vincennes's helicopter received warning fire after approaching close to Iranian gunboats, in contravention of the US rules of engagement at the time. According to the US, the gunboats had been following merchant ships in an aggressive manner and the helicopter had been deployed after they had been sighted by Montgomery. While Vincennes engaged with the gunboats, it entered Iranian territorial waters, with sharp turns causing disruption inside. In what the US government later termed "scenario fulfilment" – a form of confirmation bias in which personnel carry out a training scenario, believing it to be reality – information was erroneously communicated that not only was the aircraft squawking military codes, but that it was also descending on an attack profile. The Aegis system continued to correctly record the aircraft as climbing past 12,000 feet (3,700 m), instead, and this was reflected on the CIC's numerical displays. Captain Rogers had earlier acknowledged a remark that the aircraft was "possible COMAIR [commercial aviation]". Following the misidentification and unreciprocated radio challenges, the aircraft was shot down (see § Flight and shootdown).
Department of Defense (DoD) officials initially said that Vincennes had shot down an Iranian F-14, but issued a retraction within hours and confirmed Iranian reports that the target was instead a civilian Airbus. According to the DoD, Vincennes mistakenly identified the airliner as an attacking military fighter and misidentified its flight profile as being similar to that of an F-14A Tomcat during an attack run; however, the cruiser's Aegis Combat System recorded the plane's flight plan as climbing (not descending as in an attack run) at the time of the incident. Alongside the vague nature of the challenges issued by Vincennes, confusion may have arisen as the hailed speed stated in the transmissions was the ground speed, while the pilot's instruments displayed airspeed, a 50-knot (93 km/h; 58 mph) difference.