Confusion and contradictory statements over the cause of the accident surround Wednesday morning’s plane crash in Iran, which killed 176 people.
A Boeing 737-800 NG operated by Ukrainian International Airlines crashed shortly after taking off from Tehran, killing all on-board.
The cause of the crash is unclear and various theories have been put forward by analysts and commentators from inside and outside of the aviation industry. Investigations are being complicated by the current tensions between the US and Iran.
A series of contradictory statements and theories have confused matters in what is an already complex situation, given the hightened tensions between Iran and the US, where the plane was manufactured.
Iran has refused to hand over black box flight recorders to Boeing or US investigators but has said it will work alongside Ukraine on the investigation.
Iran's Civil Aviation Organisation (CAO), Ali Abedzadeh, told Mehr news agency: “We will not give the black box to the manufacturer and the Americans. This accident will be investigated by Iran's aviation organisation but the Ukrainians can also be present.”
But Ukrainian International Airlines promised a full investigation involving Ukraine, Iran and Boeing.
The US’ National Transportation Safety Board, which would usually have a role to play in Boeing incidents, said it has not yet been invited to participate.
Canada has offered its technical assistance and said it expects to be involved in the investigation. 63 Canadians were listed on the plane when it crashed.
Boeing issued a statement saying: “We are ready to assist in any way needed.”
But the Aviation Safety Network (ASN) said that black boxes are never 'handed over' to a manufacturer.
It added: “Per international (ICAO) agreements Iran is responsible for the investigation since the accident happened in that country and therefore for the process to decode and analyse the voice and data recorder information.”
Technical issues and engine failure were theories initially put forward by Ukraine and local media reporting in Iran.
There is speculation in the media and on social media that the plane may have been shot down. But so far there is no evidence to suggest a link to the crash and US-Iran tensions, which saw Iran launch missiles at American personnel in Iraq earlier this week.
Ukraine’s government website initially ruled out terrorism or a rocket attack but later retracted the statement, saying it was too early to draw conclusions.
ASN said that it is “too soon to speculate” on the cause of the accident. It added: “The investigation has only just started and there are too many uncertainties to draw any conclusions on what caused the accident.”
It was also reported that there was no distress message from the flight, suggesting the aircraft may have been shot down.
But ASN said that this by itself “does not prove anything”. It said: “In case of an in-flight emergency, flight crew are taught to aviate, navigate, communicate in that order. Maintaining control over the aircraft and navigating towards an airport are prioritised over making radio calls.”
Details on the aircraft and pilots
The flight crew comprised of three pilots, including Captain Volodymyr Gaponenko (11600 hours on Boeing 737), instructor pilot Oleksiy Naumkin (12000 hours on Boeing 737) and first officer Serhii Khomenko (7600 hours on Boeing 737).
Ukrainian International Airlines’ VP operations, Ihor Sosnovsky, said: “Tehran airport is anything but a simple one. Therefore, for several years UIA has been using this airport to conduct training on Boeing 737 aircraft aimed at evaluating pilots' proficiency and ability to act in emergency cases.
“According to our records, the aircraft ascended as high as 2400 meters. Given the crew's experience, error probability is minimal. We do not even consider such a chance."
- The aircraft involved was a Boeing 737-800. Its first flight was on 21 June 2016
- The aircraft operated a round trip (Ukraine International Airlines flight PS751/752) from Kyiv, Ukraine to Tehran and back
- The airline has passed the IATA Operational Safety Audit (IOSA) benchmark for global safety management
- Weather was fine with no clouds
- ADS-B data stopped three minutes after take-off
- The aircraft impacted the ground and disintegrated about 8 minutes after take-off
- All 167 passengers and nine crew members were killed. This makes the accident the:
- worst accident involving a Boeing 737-800
- second worst accident involving a Boeing 737 (all series)
- third worst accident in Iran
- 42nd worst accident in aviation history
- worst accident involving a Ukrainian aircraft
Boeing is already embroiled in the 737 Max saga, with all such models being grounded since March following two fatal crashes involving the aircraft. The grounding dealt a major blow to Boeing and its airline customers.
Many airlines rely heavily on Boeing 737 NG aircraft and more than 7,000 have been built since production began in 1998.
Investigators will take months to establish the cause of the crash, and there is no evidence to suggest that manufacturing issues contributed to the crash, but if technical issues are found to be the cause it would have huge implications for Boeing and the airline industry, which relies so heavily on 737s.
Ukraine’s President said that the country’s entire civil aviation fleet would be checked.