The report said an investigation was underway as to what had caused the malfunction of the fighter jet Iran’s air force has an assortment of US-made military aircraft purchased before the 1979 Islamic Revolution TEHRAN, Iran: An Iranian fighter jet on Tuesday developed a “technical problem” that killed both of the aircraft’s pilots, state TV reported. The report said the incident happened in the country’s southwest, in the city of Dezful, 444 kilometers (270 miles) from the capital, Tehran and near the border with Iraq. The report said an investigation was underway as to what had caused the malfunction of the Iranian air force’s F-5 fighter jet. The TV said it happened before takeoff. It did not elaborate. The report, citing an informed source, identified the pilots as Kianoush Basati and Hossein Nami, without providing their rank. Authorities were investigating, it said. Iran’s air force has an assortment of US-made military aircraft purchased before the 1979 Islamic Revolution. It also has Russian-made MiG and Sukhoi planes. Decades of Western sanctions have made it hard to maintain the aging fleet.