The plane was forced to land in Austria after France and Portugal abruptly canceled air permits for it while en route from Moscow on Tuesday, apparently due to fears fugitive ex-U.S. spy agency contractor Edward Snowden could be on board.Official Government transports typically obtain 'diplomatic clearance' to transit other countries airspace. They are clearances that have 'time frames' attached to them. For example, you may be cleared to transit the airspace anytime within a 24 hour period. These 'dip clearances' are arranged well in advance. If your flight delays or your flight plan doesn't allow you to transit within the designated dip clearance times, you have to re-submit the dip clearance request. This could delay a flight 24+ hours depending on the country response to your new request. Sometimes, a flight is delayed and the timing of the flight plan will be very close to causing the plane to transit the country at the very last moments of the clearance time and the plane will depart 'hoping' for direct routing (request radar control for direct from point a to point b, in affect, cutting out some of their flight plan points saving time) to allow them to shave time to make their dip clearance window. If they ran out of time, their dip clearance would be void and transition of the airspace (unless emergency), would be illegal.
FORCED to land, as mentioned above, meant the plane was forced to land because they likely didn't have the fuel to go around the airspace of the 2 countries and still reach their destination, didn't have dip clearances to transit other airspace not originally on their fight plan, or, the couldn't re-file their flight plan in flight to be able to 'fly around' the 2 countries that revoked their dip clearances. They likely weren't intercepted by the French or Portuguese.
Once the plane landed in Austria, immigration likely searched the airplane. Now understand normally an aircraft (government) is sovereign territory and can't be boarded without permission of the aircrew. This is why Austria was 'allowed' to search. Plus, if the prez wanted to go into the terminal, flight crew wanted to go in the terminal to file a new flight plan, and if they wanted to get fuel without a hassle from the Austrians, it was in their best interest to be boarded.
Remember, Austria wasn't aware the plane was coming. In fact, they likely landed there so they could re-file, put in new request for dip clearances, and get fuel. Also, all their other dip clearances were likely going to expire since they were delayed.
I could go on but why? It's all purely speculation as to why their dip clearances were a problem with France and Portugal.
I just wanted to add some things to consider based on 20+ years of international, government travel.... as an aircrew member.
![happy :D](./images/smilies/happy_002.gif)
I don't get mad at the people, I get mad at the situation!