in Isfahan with a serial number of 90–05. It was registered to Sepahan Airlines with a registration code of EP-GPA. At the time of the accident, the aircraft had accrued a total of 1,370 flight hours and 1058 hours of flight cycles. The aircraft was equipped with two engines. The left engine was manufactured in 2007 and had accrued a total of 1,311 cycles. The right engine was manufactured in 2004 and had accrued a total of 1,329 cycles. The Antonov An-140 (upon which the HESA IrAn-140 is based) is a relatively recent development, with knock-down kits being delivered for domestic Iranian assembly as recently as 2007. Passengers and crew There were 42 passengers and a crew of six. Of the 42 passengers, 36 were adults and six were children. 34 passengers and all six crew members were killed in the accident. The pilot flying was a 63-year-old captain and had accumulated a total of more than 9,400 hours of flying, including 2,000 hours as a pilot on the Antonov An-140. He held a certificate for flying the Antonov An-140 since May 2014. Examination on the medical records revealed that he had no medical limitations and that he was not fatigued during the crash. The pilot not-flying was a 32-year-old captain and had accumulated a total flying time of 572 hours, 400 of which were on the Antonov An-140. He began his transition training as a Captain of Antonov An-140 in September 2005. Documents revealed that he was well-rested during the crash. Investigation Right engine failure Survivors recalled that the right engine of the aircraft malfunctioned during its take-off. Analysis on the aircraft's logbook revealed that numerous errors and failures had been recorded on the right engine. In April 2014, at least 2 engine failures were recorded. On 23 April and 24 April, while en route to Bandar Abbas, the right engine failed during the aircraft's cruising stage. On 28 April, the engine failure warning light was illuminated for a short time. On 29 April, during the inspection on both engines, a corrosion on the left engine's compressor blade was discovered by ground crews. Just 3 days before the crash, on 7 August, during its flight from Tabriz to Isfahan, a violent shaking was recorded on the right engine. The FDR recorded this shaking and the warning alarm was triggered. A sensor replacement was conducted to eliminate the problem. However,