The Iranian Civil Aviation authority released the report, citing witnesses. It said the plane also changed directions after a problem and turned back toward the airport. The Boeing 737 crashed shortly after takeoff from Tehran early Wednesday, killing all 176 people aboard.At first, Iranian state media blamed technical issues on the crash while Ukraine ruled out rocket attacks. But officials in both countries have since walked back their statements and declined to speculate on the cause.Given the level of the crew's experience, it's unlikely the crash was the result of error, Ukraine International Airlines said. Tehran's airport is complicated and the pilots required several years of training to use it, said Yevhenii Dykhne, president of Ukraine International Airlines. The captain had 11,600 hours of flying on a Boeing 737 aircraft while the pilot had 12,000 hours on the aircraft. The crash came hours after Iran fired missiles at two Iraqi bases housing US troops in retaliation for the killing of its general, leading to speculation over the timing of the incident.

A fireball in the sky

The Boeing 737 jet was operated by Ukraine International Airlines. It took off early Wednesday headed to the Ukrainian capital of Kiev with 167 passengers and nine crew members. Witnesses have described seeing a fireball in the sky before the plane crashed. Images of the wreckage show charred parts of the plane strewn over a field. The victims are from several nations, including 82 Iranians, 63 Canadians, 11 Ukrainians, 10 Swedes, four Afghans, three Germans and three British nationals, Ukrainian officials said. Ukrainian President Volodymyr Zelensky has declared Thursday a day of national mourning.

Iran refuses to work with US

As authorities work to determine the cause of the crash, tensions between the United States and Iran are threatening to complicate the investigation.Hostilities between Tehran and Washington have escalated after Iran fired missiles at Iraqi bases housing American troops. The missiles were in retaliation for a US strike that killed Iran's top commander, Qasem Soleimani, on Iraqi soil last week. While it's unclear whether the incidents are related to the plane crash, tensions between the two adversaries are spilling over to the investigation. Searchers have found the plane's black boxes — a cockpit voice recorder and flight data recorder — which could offer crucial evidence about what happened to the plane leading up to the crash, the Tehran prosecutor told Iranian state media. But Iranian officials don't plan to share information from the black boxes with the plane's manufacturer, US company Boeing, as is usual in crash investigations. "We will not give the black box to the manufacturer or America," Ali Abedzadeh, the head of Iran's Civil Aviation Authority, told the semi-official Mehr news agency.The US will not be involved aRead More – Source