These planesVideo footage by Iran's ISNA news agency purports to show the plane on fire in the seconds before it crashes into the ground, which is corroborated by Qassem Biniaz, a spokesman for Iran's Road and Transportation Ministry, who said it appeared a fire struck one of its engines.
Hassan Razaeifar, the head of air crash investigation committee, said it appeared the pilot couldn't communicate with air-traffic controllers in Tehran in the last moments of the flight and witnesses said the pilot steered the plane towards a football field to avoid a residential area.
'https://en.wikipedia.org/wiki/Boeing_73 ... Generation
have French or US built engines, see below
The engine failures have been related to fan blades. One was the famous one where debris flew threw a passenger window and killed one passenger while being sucked outAccording to the Aviation Safety Network, the Boeing 737 Next Generation series has been involved in 15 hull-loss accidents and 10 hijackings, for a total of 590 fatalities. The worst occurrence involving the 737NG was Ukraine International Airlines Flight 752 on January 8, 2020, with 176 fatalities, surpassing the 2010 accident of Air India Express Flight 812. An analysis by Boeing on commercial jet airplane accidents in the period 1959–2017 showed that the Next Generation series had a hull loss rate of 0.17 per million departures versus 0.71 for the classic series and 1.75 for the original series.
https://en.wikipedia.org/wiki/CFM_Inter ... 6-7_series
It had fan blade issues since 1989 when all engines were rebuilt
The 1989 crash was famous for its confusion of engines. The flight crew failed to tell the captain which side the smoke was coming from. If they had known which engine to shut down the plane would have landed safely.Less than a month after (1989) grounding, the fleet was allowed to resume operations once the fan blades and fan disc were replaced and the electronic engine controls were modified to reduce maximum engine thrust to 22,000 lbf (98 kN) from 23,500 lbf (105 kN). The redesigned fan blades were installed on all CFM56-3C1 and CFM56-3B2 engines, including over 1,800 engines that had already been delivered to customers.