24.06.2021 Aviation law and defence

Legal aspects of Ryanair forced landing in Minsk

One of the events of the last decade of May which attracted the widest attention was the case of Ryanair flight 4978 from Athens to Vilnius. The plane on this flight was diverted from above the Belarus-Lithuania border and, as announced in the press, forced to land at the Minsk National Airport. This case, though not completely clear in many details, makes one ask some questions of a legal nature.

Let us remind the facts

On 23 May 2021, a Ryanair’s Boeing-737-8AS registered in Poland as an SP-RSM owned by the Polish subsidiary Ryanair Sun S.A. was on a regular flight no. 4978 from Athens to Vilnius. There were 6 crew members and 126 passengers on board the plane and among them the journalist Raman Protasiewicz, a well-known critic of actions of the authorities in Minsk, and his partner Sofia Sapiega. At 12.30 p.m. the plane flew into Belarusian airspace maintaining the designated corridor. A few minutes later a controller from Minsk, quoting a letter received by the Belarusian authorities, informed the crew that there might be a bomb on board.

At 12.45 p.m., when the Ryanair plane was 45 NM (83km) away from the destination airport in Vilnius, following instructions from the Belarusian traffic control the crew started to change plane’s heading and prepared to land at the airport handling the capital of Belarus. The Boeing was to be accompanied by a MiG-29BM from the 61. Baranovichi Air Base. The pilot of the Ryanair plane set transponder code 7700 meaning danger.

At 1.21 p.m. the Boeing landed in Minsk. It resumed its flight to Vilnius not earlier than at 8.47 p.m. after numerous interventions and requests to release both the plane, plane’s crew and the passengers made to the Belarusian authorities, among other things, by the Prime Minister of the Republic of Lithuania Ingrida Limonite. However, six individuals – Raman Protasiewicz, Sofia Sapiega and four Russian passengers – did not reappear on board. The oppositionist and his partner were detained and then put in prison.

As a side remark, it has to be noted that no explosives or other dangerous materials were found on Boeing’s board.

The reactions to this incident on the part of the EU and NATO member states were definitely negative. The International Civil Aviation Organisation announced detailed examination of the forced landing of flight 4978.

Incident in the light of aviation law

The incident which occurred on 23 May has, or may have, serious repercussions in the light of international aviation law which in this context should be considered from several perspectives. The issues to be analysed from the point of view of the applicable aviation standards may be divided into the following categories:

  • The issue of a potential threat to the aircraft, its crew and passengers
  • Genuineness of information about the bomb on Boeing’s board
  • Legitimacy of directing the plane to the Minsk airport
  • Legitimacy of use of a fighter aircraft
  • Legal consequences of the incident

Though each of the above is a separate legal issue which requires a proper and through analysis, nonetheless they jointly give the overall picture of the events which took place on 23 May 2021 in Belarusian airspace.

Freedoms and obligations

Belarus is a member of the International Civil Aviation Organisation, namely a UN specialised agency whose task is to develop and implement international regulations governing international air navigation safety. It is also a party to international agreements applicable in civil aviation, including, among other things, the Chicago Convention[1] and the Montreal Convention[2], which has particular consequences, and especially obligations aimed at ensuring efficient and safe aviation communication.

First of all, one has to pay attention to the so-called freedoms of the air, i.e. rules according to which carriers may fly using foreign airspace. In the described case of the flight from Athens to Vilnius across the territory of, among other things, Belarus we are dealing with a practical application of the first (the right to fly across the territory of a third country without landing) and the seventh freedom of the air (the privilege of transporting passengers and loads between territories of two different countries by aircrafts of a third country, without landing on the territory of that last country)[3].

On the other hand, one has to bear in mind that pursuant to Article 1 of the Chicago Convention every country has complete and exclusive sovereignty over the airspace above its territory (principle of sovereignty). This principle gives rise to certain rights and obligations which concern, in particular, organisation of air navigation.  The basic right of the country is to prohibit flying across its own airspace for safety reasons. A country may also make flights of foreign aircrafts across its own territory conditional on detailed rules determined by itself. It also has a possibility to divide its own airspace and regulate the manner in which it is used, as well as apply legal means of coercion with respect to aircrafts which do not follow instructions of relevant services.

Each country is responsible for regulating airspace above its own territory and ensuring air navigation safety.

A bomb threat?

Significant issues which affect evaluation of the incident of 23 May 2021 are those related to a potential threat to the aircraft, its crew and passengers caused by a bomb being possibly placed on Boeing’s board, as well as genuineness of information about such a bomb.

There is no doubt that placing a bomb or any other device or substance which may destroy the aircraft or cause damage, or pose a threat to its safety during flight constitutes an offence under Article 1 clause 1 letter c) of the Montreal Convention. On the other hand, in accordance with the Montreal Convention (Article 1 clause 1 letter e) communicating information which the communicating person knows to be false, thereby endangering the safety of an aircraft in flight, is also an offence.

Attempts at committing the above offence and cooperation with the person who commits or attempts to commit the offence are also penalised.

As mentioned at the beginning, a bomb or any other device which could destroy the plane or pose any other threat to flight safety was not found on Boeing’s board. Thus, one should focus on the second of the above issues, namely genuineness of information about a possible threat to aircraft’s safety provided to the crew of the Ryanair’s Boeing by the Belarusian air navigation services.

Evaluation is in this case more difficult, as obviously we have information coming from the participants of this event only, having no access to information about the bomb (if it really existed) provided to the Belarusian special services and/or relevant bodies of the air navigation services.

According to the provisions of Annex 17 to the Chicago Convention[4], each country is obliged to apply relevant preventive measures with respect to acts of unlawful interference (which encompasses, among other things, introducing weapon, explosives or other dangerous articles on board an aircraft), as well as properly react and communicate information when discovering an act of unlawful interference.


Correspondence between the air traffic service and Boeing’s crew with regard to the alleged bomb on board the aircraft gives rise to certain doubts in this case, and particularly the changing versions concerning the origin of information about the threat: initially, such information was to come from special services, while later on the controller talked about an e-mail sent to airport services of “several airports”.

If the authorities in Minsk had really received information about a bomb threat, they should have informed the countries concerned, i.e. in this case Lithuania as the country of the destination airport.

A subsequent search of the Ryanair’s Boeing showed that any information about a bomb had to be false. This gives rise to another question: was the person who on behalf of Belarusian air traffic services informed the aircraft crew about the bomb threat aware that the provided information was false?

If so, then we would be dealing with the offence set out in the Montreal Convention mentioned above. In such an event, according to the provisions of the Montreal Convention, also individuals who cooperated with the person who committed the above act would be subject to criminal liability.

What may help in evaluating existence of the prerequisites of the acts mentioned above are recently disclosed circumstances concerning an e-mail sent by a person calling himself a “Hamas soldier” to the authorities of the Minsk Airport. According to the latest findings, this e-mail was received by the airport several minutes after the Belarusian controller had informed the crew of the Boeing about the bomb threat.

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On a MiG to Minsk

A completely separate issue in the case under discussion are the events which occurred after the crew of Boeing 737-800 had been informed about the bomb, which resulted in plane’s landing on the Minsk international airport, and their potential legal consequences.

The Ryanair’s plane is known to have been diverted from its route when it was near the Belarus-Lithuania border and it had 45 NM (83 km) left to the destination airport in Vilnius. According to information from the popular website Flightradar24.com, the Boeing was above Lida when starting to change the course to approach the airport in Minsk.

In case of a bomb threat, as well as other threats to the safety of the aircraft and individuals on board, it is a rule to land at the nearest airport available, obviously if it is adjusted to receive a plane of a given type. In the discussed case the nearest airport was the one in Vilnius and it is there, according to applicable procedures, that the plane should head. So, why the commander of the aircraft eventually decided to land in Minsk?

Maybe his decision was influenced by information from the Belarusian air traffic controllers that the bomb would be detonated above Vilnius. Anyway, having been informed by the air traffic controllers about the “red code” threat degree, the crew decided to ask for the course for Minsk and information necessary to approach the airport, at the same time changing the transponder code to 7700 and sending out a “Mayday” message.

It is also worth to refer to information which in the Western countries set off a kind of a firestorm concerning Boeing’s interception by an armed MiG-29. In accordance with Article 3 bis letter b) of the Chicago Convention, every country, in the exercise of its sovereignty, is entitled to require the landing at some designated airport of a civil aircraft flying above its territory without authority or if there are reasonable grounds to conclude that it is being used for illegal purposes. On the other hand, pursuant to letter c) of this provision, every civil aircraft is obliged to comply with an order given in conformity with the above provision.

According to Appendix 2.1 to Annex 2 to the Chicago Convention, interception of a civil aircraft should be undertaken only as a last resort and should be limited to: a) determining the identity of the aircraft, unless it is necessary to return the aircraft to its planned track; b) directing it beyond the boundaries of national airspace; c) guiding it away from a prohibited, restricted or danger area; d) instructing it to affect a landing at a designated airport.

Unfortunately, we do not have any recordings of radio correspondence (if such was maintained) between the Boeing’s crew and the MiG’s pilot, thus not knowing whether the military plane gave any instructions to the aircraft of Ryanair or if their communication was limited to non-verbal signals. Also, one cannot exclude that the interception was limited to the Boeing being accompanied by the airplane of the Belarusian Air Forces only. There are many question marks at this stage. Maybe the coming days and ICAO’s examination of the case will shed a new light on the circumstances of this event.

Nonetheless, in my opinion, it is at least premature to claim that the Belarusian fighter aircraft posed any threat to the Boeing, its crew and passengers. The more so that the crew of the Ryanair plane do not confirm any contact with MiG at all. As a side remark, replying to the appearing voices of outrage that an armed plane was sent, it has to be stated that having armed fighter aircrafts on duty is a worldwide standard and it is absolutely groundless to seek here any signs of bad will on the part of the authorities in Minsk.

However, if Boeing’s interception by MiG-29 is really the case and the pilot of the latter gave instructions to land in Minsk, then the commander of the passenger plane should comply with such a request.

Anyway, in my opinion, the issue of Ryanair’s plane landing in Minsk rather than in Vilnius needs to be thoroughly examined by ICAO from the perspective of Minsk’s potential violation of safety procedures in case of a bomb threat.

Possible consequences

If it is confirmed that the Belarusian authorities committed a prohibited act referred to in the Montreal Convention, then Poland as the country of Boeing’s registration could bring an action against Belarus to the International Court of Justice in Hague. However, there is a problem at this point, since Belarus (still as Byelorussian Soviet Socialist Republic) filed an objection to Article 14 of the Convention establishing jurisdiction of the International Court of Justice. Thus, even if the case was brought to ICJ, then the court would certainly discontinue the proceedings due to the lack of jurisdiction.

However, it seems that the case could be referred for settlement to the ICAO Council under Article 87 of the Chicago Convention. In such an event the parties would be able to appeal against the decision of the Council to ICJ.

What is more, it may turn out that Belarus also violated Article 10 clause 2 of the Montreal Convention by keeping the plane, crew and passengers at the airport in Minsk for over seven hours making it impossible for them to continue the journey. The discussed provision refers to the need “to make it easier, as soon as possible, for the passengers and the crew to continue the journey”. Thus, if it is proven that plane’s stay in Minsk, and consequently the break in the journey, lasted longer than it was necessary due to the suspected bomb threat, it may form another basis of an action against Belarus.

Thus, potentially in the case of the events of 23 May we would be dealing with a blatant violation of two separate international agreements by one country, which happens rather rarely nowadays. Such a case could be brought to the International Court of Justice, either directly or as a result of an appeal against the decision of the ICAO Council, with all consequences of this.

The authorities in Minsk, in case of an unfavourable judgment, would face the need to pay damages to Poland as the country of aircraft’s registration and the injured party in the light of international law.

Possible request for Protasiewicz’s release?

What is more, referring to a precedent from the decision of the Permanent Court of International Justice (ICJ’s predecessor) on the Chorzów nitrogen factory of 1928, Belarus could be made to “remove all consequences of illegal conduct and restore the situation to a condition which would take place if the violation of international law had not occurred”. In other words, on this basis it would be possible to request that Raman Protasiewicz and Sofia Sapiega be released and be able to continue their journey to Vilnius, just as it would happen, if Belarus did not violate international provisions of aviation law. And Protasiewicz’s nationality or citizenship is of no importance here, as shown by the precedent in the Arctic Sunrise case of 2013 when the Russian Federation was obliged by ICJ to release the Dutch Greenpeace ship with the crew which included Russian citizens.

Serious consequences

If it is confirmed that Belarus intentionally procured a false bomb alarm only to force flight 4978 to land and arrest Raman Protasiewicz, this would constitute a dangerous precedent and a significant breach of the existing legal order governed by aviation law standards, and could hypothetically encourage other countries to act in a similar way. Such conduct, which may consequently threaten the safety of journeys by air, cannot be tolerated.

I believe that it is the European Union that will have a lot of work in this particular case. Flight 4978 was an intra-EU flight of an EU carrier on an aircraft registered in the EU. Brussels should find an answer to the question about what the EU can do in order to protect its carriers and passengers against similar conduct of authorities of third countries, especially the ones which take international opinion into account to an unsatisfactory degree.

The first steps taken by the EU are promising – the strong reaction of the President of the European Commission and summons to the Belarusian ambassador make one hope that the case will have some consequences. One of the effects of the incident of 23 May was closure of EU’s airspace for Belarusian aircrafts.

Any further consequences will most likely depend on the results of the explanatory procedures before the ICAO bodies.


Piotr Dudek
Director of the New Technologies, Defence & Aerospace, Advocate
TGC Corporate Lawyers

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  • [1] Convention on international civil aviation signed in Chicago on 7 December 1944, adopted and ratified by the Council of the Polish People’s Republic on 20 November 1958 (Dz. U. of 1959, No. 35, item 212)
  • [2] Convention for the suppression of unlawful acts against the safety of civil aviation executed in Montreal on 23 September 1971, signed and ratified by the Council of the Polish People’s Republic on 14 November 1974 (Dz. U. 1976, No. 8, item 37)
  • [3] The first five freedoms of the air stem directly from the Chicago system, while the next ones – from the sixth one on have not been officially included in the treaty framework so far
  • [4] Annex 17 to the Convention on International Civil Aviation “Safeguarding International Civil Aviation Against Acts of Unlawful Interference”

See also

13.03.2024 Aviation law and defence
14.12.2023 Aviation law and defence
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