What are the rules about flying in another nation’s airspac…

The principles of international air travel were agreed at the 1944 Chicago Convention. WW2 had revolutionised aircraft development and forward-thinking people realised that the rules needed to catch up to accommodate airline travel after the war.

Delegates from 54 countries attended (at considerable personal risk for some) to thrash out a treaty. They had to balance national sovereignty against the co-operation needed for this new means of rapid global transport to work.

Germany, Italy and Japan were not invited (it was 1944) but signed afterwards along with pretty much everyone else. There are now 193 members of ICAO (the body Chicago established) including Belarus.

https://t.co/7qMYlK5E0s

Article 1 of the Convention recognises that states have sovereignty over the airspace above them (although the development of another new technology: space means the rules need to catch up again and agree an upper limit).

In Article 3 states agree not to use weapons against civil aircraft in flight.

However, this is qualified by the UN Charter i.e. the right of self defence. This is why the RAF can intercept non-responding airliners & would be the legal basis for shooting down a hijacked aircraft about to carry out a 9/11-style attack (pic: legal intercept of Ryanair).

States may require an aircraft to land if (a) it doesn’t have permission to fly in their airspace or (b) it is ‘being used for any purpose inconsistent with the aims of this Convention’ i.e. peaceful air travel. Neither of these conditions applied to Ryanair 4978.

So what if an airliner is intercepted? The signals used by intercepting aircraft must be published and pilots should be familiar with them to avoid any misunderstanding. Under the Convention, pilots must comply (so the Ryanair crew had no choice).

However, interception of civil airliners by military aircraft may only take place if the aircraft is there without permission, or if a state has reasonable grounds to believe it is not engaged in peaceful air transport.

So in summary states have a sovereign right to decide who flies in their airspace, and to ensure that they do so safely. They do not have a right to force airliners to land so they can arrest political opponents. That's hijacking.

End.