The helicopter in the crash that killed Iranian President Ebrahim Raisi was a US-made Bell 212, a model introduced in 1968 during the Vietnam War and last produced in 1998.
Here is what we know about the Bell 212:

Decades-old helicopter
Brought into service in 1971, the civilian helicopter had a military version known as Twin Huey, which was used by US troops during the Vietnam conflict.
One of its variants, the Huey UH-1 Iroquois, gained notoriety in an iconic scene in the film Apocalypse Now during which US troops play Richard Wagner’s The Ride of the Valkyries on loudspeakers during a raid on a Vietnamese village.
The Bell 212 can carry 13 passengers plus two pilots and fly at more than 250km 156 miles per hour, with a range of more than 400km.
It features a two-blade propeller and is equipped with two Pratt and Whitney engines of 900 horsepower each.
The helicopter was first manufactured in Fort Worth, Texas, before production moved to Mirabel, outside Montreal, from 1988 until 1998, the last year it wast built. It was also made under license in Italy by Agusta.
As of last year, 704 Bell 212 or Bell 412 — its four-blade version — were still in service among armed forces, including in Angola, Argentina, Morocco, Turkiye and Zambia, according to the most recent annual report of industry publication FlightGlobal.

Flying under sanctions
As of 2023, Iran operated 10 Bell 212 helicopters — two used by the air force and the remainder by the navy, according to FlightGlobal.
Tehran was an important client for the American civilian and military aircraft industry under the Shah of Iran, a close US ally, until his ouster by the Islamic revolution in 1979.
Iran has sought to keep its ageing fleet in the air despite US sanctions that have it made very difficult for Tehran to obtain spare parts.
It still has around 40 F-14 Tomcat fighter jets, which became famous in the Tom Cruise film Top Gun in the 1980s and have been used by the US Air Force itself for two decades.
Iran also has a number of F5 fighters, purchased from the United States four decades ago and which first came into service 60 years ago.

The Bell maker
The Bell company, which was founded in 1935 and became a subsidiary of industrial group Textron in 1960, still produces helicopters.
The firm prides itself on having been the first to certify a helicopter intended for civilian use, in 1946.
A year later it was an experimental Bell X-1 aircraft that Chuck Yeager piloted as he became the first man to surpass the speed of sound in 1947.