Western intelligence agencies believe that a Ukrainian plane that crashed Wednesday in Iran suffered a technical malfunction and was not shot down, the Reuters news agency reported.
The Ukraine International Airlines Boeing 737-800 crashed less than three minutes after taking off from Tehran’s airport, killing 176 people, mostly Iranians and Canadians.
The report quoted five unnamed security sources — three American, one European and one Canadian — as saying the initial assessment is that Tehran’s explanation is accurate. The Canadian source was quoted as saying there was evidence one of the aircraft’s engines had overheated.
Qassem Biniaz, a spokesman for Iran’s Road and Transportation Ministry, said it appeared a fire erupted in one of its engines and the pilot lost control of the plane, according to the state-run IRNA news agency. The news report did not explain how Iranian authorities knew that.
The pilot apparently couldn’t communicate with air-traffic controllers in Tehran in the last moments of the flight, said Hassan Razaeifar, the head of the air crash investigation committee. He did not elaborate.
However, an aviation expert has expressed skepticism about the immediacy in which Iran claimed a mechanical problem was the cause of disaster.
“I don’t see how they would have known that so quickly,” said John Hansman, an aeronautics professor at MIT. “They hadn’t had time to look at the flight data recorder. They probably hadn’t had time to investigate the physical wreckage of the engines. How do you know it was a mechanical issue versus a surface-to-air missile that went in the engine?”
Many planes have systems that send huge amounts of technical data, including potential problems with the engines or other key systems, to the airline and the manufacturer. But it was unclear whether Ukraine International had paid to download that information automatically during flights, or how much data from such a short flight would tell.
Ukraine International Airlines President Yevhen Dykhne, said the aircraft “was one of the best planes we had, with an amazing, reliable crew.” In a statement, the airline went further, saying: “Given the crew’s experience, error probability is minimal. We do not even consider such a chance.”
A Boeing spokesman declined to say whether the company obtained any information about the jet during its ill-fated flight.
While clear international rules govern investigations into air crashes, in this case they could fall victim to heightened tensions between Tehran and Washington.
Tehran has already indicated it will not hand over to Americans the recovered flight recorders, the so-called black boxes, for investigation.
The rules on probes into air crashes are set down in the 1944 Chicago Convention on International Civil Aviation, and the responsibility for the investigations is assigned to the countries where they occur.
This puts Iran in charge of the investigation, but the country that manufactured the aircraft and the country of the airline that operated the plane are also supposed to have representatives involved in the probe.
In theory this means that the US National Transportation Safety Board (NTSB), which is the body charged with investigating air accidents, would be involved as Boeing is based in the United States, and would likely rely on experts from the manufacturer.
“That could be a little complicated,” noted Jean-Paul Troadec, former head of France’s BEA airline safety agency.
The crash came on the same day that US-Iranian tensions hit new heights as Iran fired a volley of missiles at Iraqi bases housing US and other foreign troops, the Islamic Republic’s first physical response since the US killed top Iranian general Qassem Soleimani.
Boeing said it was in contact with Ukraine International Airlines and that it was “ready to assist in any way needed.”
However, the head of Iran Civil Aviation Organization head, Ali Abedzadeh, said while the Ukrainians were free to participate in the probe into the crash, “we will not give the black boxes to the manufacturer (Boeing) and the Americans,” according to the Mehr news agency.
An NTSB spokesman told AFP the group was tracking developments and would follow normal procedures regarding international accidents.
The NTSB was also in contact with the US State Department to determine the best way to proceed with respect to Iran, the spokesman said.
In Washington, US Secretary of State Mike Pompeo said in a statement: “The United States calls for complete cooperation with any investigation into the cause of the crash.”
Reading information from the cockpit voice recorder and flight data recorder is not in itself difficult, according to Troadec.
“The difficulty is if the recorders are in very poor condition, then you need labs which have the experience and equipment” in recovering data, he said.
Besides the NTSB, Troadec said the BAE and its counterparts in Britain and Germany have the know-how to handle data recovery in such situations, and possibly the Russians.
The BEA said it has yet to receive any request for assistance from the Ukrainian authorities.
The Chicago Convention also allows a country to let another country take charge of a probe.
Dutch authorities carried out the investigations into the 2014 crash of a Malaysia Airlines that crashed in Ukraine as it returned home from Amsterdam, killing 298 people including 193 Dutch nationals.