Belarus’s ministry of transport has detailed the circumstances of the Ryanair Boeing 737-800 diversion to Minsk, releasing a transcript of the air traffic control exchange, in a bid to demonstrate that the crew was not pressured into its decision to land at the airport.

The ministry’s aviation division insists that its account is “proof” that the pilots of the Athens-Vilnius flight on 23 May were “not pressured, threatened or coerced”.

It claims that Minsk airport’s operator received a message in English, from an encrypted email service, purportedly from the Palestinian movement Hamas demanding an Israeli ceasefire following the recent hostilities in Gaza – although such a ceasefire had already been implemented by 21 May, two days before the Ryanair flight.

The message referred to a bomb on the aircraft, aimed at attendees returning from the previous week’s Delphi Economic Forum in Greece, and added that it would “explode…over Vilnius”.

Minsk airport’s operator sent the message to Belaeronavigatsia, the country’s air navigation service, says the ministry.

Cruising at 39,000ft the flight entered the Minsk flight information region at 12:30 local time – some 2h 20min after departing Athens – via the SOMAT waypoint on the border between Ukrainian and Belarusian airspace.

While the ministry has not stated when the email threat was received, the transcript indicates the crew was notified of the threat as soon as it was transferred to Belarus area centre controllers.

Ryanair SP-RSM-c-Andrzej Otrębski Creative Commons

Source: Andrzej Otrebski/Creative Commons

Ryanair was operating flight FR4978 from Athens to Vilnius on 23 May

“For your information we have information from special services that you have a bomb on board and it can be activated over Vilnius,” the radar controller stated, before repeating the message and advising the aircraft to divert to ‘UMMS’, the ICAO code for Minsk airport.

The transcript shows the pilot queried the source of the message, and was told that it was received by airport security personnel.

When the pilot asked whether the airport staff concerned were in Vilnius or Greece, the controller did not specify but stated: “This email was shared to several airports.”

This prompted the crew to ask for the Ryanair operational control frequency but the pilots were told to stand by.

Radio transmission clarity was only moderate and parts of the exchange were unintelligible. Still without the information they requested, the crew sought the IATA code of the diversion airport and was told ‘MSQ’ for Minsk.

“This recommendation to divert to Minsk, where did it come from? Company?” the pilot asked. “Did it come from departure airport authorities or arrival airport authorities?”

The controller simply responded: “This is our recommendation.”

Shortly afterwards the controller passed the Vilnius ground staff frequency of 131.75MHz to the crew, before pressing the pilots for a decision. The crew asked for a colour code – presumably to understand the seriousness of the security threat – and was told: “They say code is red.”

When the pilots responded by asking to hold position, they were told to maintain the aircraft’s altitude of 39,000ft and execute turns at their discretion. About 2min after being told about the ‘red’ colour code, the crew appears to have decided to divert to Minsk and declare an emergency, transmitting a ‘Mayday’ call, setting the transponder to squawk ‘7700’, and requesting a descent to 10,000ft.

The aircraft was cleared to descend and vectored via the KOLOS waypoint before being told to follow the KOLOS 2H arrival pattern for runway 31R.

Its crew requested a change of course for weather avoidance before advising of 133 occupants on board and being handed to Minsk approach control. The flight was then vectored for an ILS approach to the runway, with additional weather-avoidance manoeuvring.

After asking whether approach control was aware of the situation, and whether the aircraft would be parked in a specific area of the airport, the pilot added: “Just wanted to know if our company was informed about…this event.”

In response the approach controller said: “We will try to pass information to your company [in] five minutes.”

The purported transcript, which continues to the point where the crew is told to contact the tower, does not contain any reference to a military interception. The aircraft landed at 13:15, some 45min after entering the Minsk FIR.

Minsk area control centre had tried “several times” to call Ryanair’s office in Lithuania during the event, the ministry claims, but could not reach the airline’s representatives.

“Taking into account the crew decision, the air traffic control authorities of [Belarus] provided them with all the necessary priority assistance,” it adds. “A contingency plan was put into effect at [Minsk airport], all relevant services of the airport and other interested state bodies were notified and alerted in the prescribed manner.”

It says it is publishing the air traffic control exchange as “evidence…that the [captain] took his own decision to land at [Minsk] without any pressure from Belarusian side”.

The 737 was assigned to an isolated parking space where security inspections of passengers, crew and baggage were conducted. Procedures were completed by 16:20 and the flight subsequently departed for Vilnius, the ministry states.

It says that, according to its preliminary assessment, the various Belarusian parties “acted in accordance” with ICAO requirements. But it has set up a commission to look into the circumstances of the incident, and is extending an invitation to international air transport and regulatory representatives.