Can a general aviation aircraft be forced to land when crossing the airspace of a country?

Question

I don’t know how to fly yet but my friend has a Cessna, he says it’s awesome to have and fly one and he also said he will take me for a flight one day.
I have been researching and reading online and I have a question because I’m a bit scared.
So in order to take your plane for a flight, you have to file a flight plan and when you are flying you have to, using the radio, let them know that you are on your way. Let’s say I’m flying from Italy to Germany by going over Austria and I have filled the flight plan and all the necessary paperwork.
Can the Austrians ask me to land in their country for any reason, even if I’m only going over their country to go to Germany and they have notified of this before the flight?
Will they shoot me down if I don’t comply with them and land in Austria?

Answer 1

So in order to take your plane for a flight, you have to file a flight plan and when you are flying you have to, using the radio, let them know that you are on your way.

Not necessarily. It's usually a good idea to file a flight plan for flights from point A to point B, but not all flights are like that. Quite a few flights, particularly in general aviation (GA), take off from some location, fly along some route which may or may not be predetermined, and then fly back to the original location. For those, filing a flight plan is not necessarily beneficial.

Also, a flight plan is typically only required if you will be flying under what is known as Instrument Flight Rules (IFR), or when you are flying internationally. While private pilots can get the ratings (and have the equipment) to fly IFR, I dare say that far more private flights are flown according to Visual Flight Rules, or VFR. VFR is largely similar to how you drive a car; you look out the window, avoid flying into terrain or other aircraft, and navigate by various landmarks. The only major differences are that you're working in three dimensions, and that there are far fewer road signs up at a few thousand feet above ground level and above.

For communications, both with people on the ground and with other aircraft, it's normal to use the radio for voice communications. Larger airplanes are sometimes equipped with text communications systems, similar to a fancy text messaging system on a cell phone, but I dare say very few aircraft owned by individuals are so equipped.

Let’s say I’m flying from Italy to Germany by going over Austria and I have filled the flight plan and all the necessary paperwork. Can the Austrians ask me to land in their country for any reason, even if I’m only going over their country to go to Germany and they have notified of this before the flight?

They certainly can, in principle.

About 17 years ago, there was an event in the United States which caused the grounding of all aircraft in the country all at once. It's not a completely unreasonable guess that any that didn't comply might have been dealt with by force. The US is somewhat different from the EU, being so large and having few neighboring countries, but there's no reason why something similar couldn't possibly happen in the EU. Countries have authority of their airspace, and can choose who flies through it and who doesn't, when and where.

That said, the question you should be asking is more along the lines of how likely is it? The answer to that is "very unlikely"; if you've had a flight plan approved before departure, it's very rare for it to be revoked half-way through the flight.

Will they shoot me down if I don’t comply with them and land in Austria?

Technically, they can. In practice, unless you pose an immediate threat, that is extremely unlikely to happen. Even if you do seem to pose a threat, you will be given multiple chances to sort things out before it gets close to such extreme measures.

If the Austrians do anything in such a situation, it seems more likely that they would deny you entry or require you to return to the country of origin; in your case, back past the border to Italy. Once you're back in Italian airspace, what you do is up to you and to Italian Air Traffic Control.

You might also want to check out ICAO's Manual concerning Interception of Civil Aircraft (hat tip to bogl for mentioning that one here).

But frankly, you are overthinking it. In practice, countries don't go around shooting down planes flying on filed and approved flightplans and which are in contact with air traffic control. It's unlikely that you'd even be making international flights without considerable practice, and by that time, you'd know what's expected of you in both controlled and uncontrolled airspace, and know how to comply with instructions.

If you want to fly, or even pursue a pilot's license of your own, then I encourage you to give it a try. Not everyone who tries will have what is required to get a pilot's license, but there's no way to know if you don't try. Worst case, you'll have gained a number of experiences.

Answer 2

So in order to take your plane for a flight, you have to file a flight plan

Usually incorrect. Flight plans are only needed for international and for IFR flights. But there are some countries where a FPLN is required for every flight, but not Italy, Austria or Germany.

when you are flying you have to, using the radio, let them know that you are on your way

Only if you've filed a Flight Plan. If you haven't, then there's no need to announce your flight.

Can the Austrians ask me to land in their country for any reason

They can, it's their country. But unless you're a criminal or a terrorist, there's probably no reason for them to actually do this.

Will they shoot me down if I don’t comply with them and land in Austria?

If they ask you to land (see above) and you don't, then they could shoot you down. It's their country and they're trying to protect it. But it hasn't happened yet.

Answer 3

Aviation in general is very much driven by safety. Most topics covered during training therefore directly or indirectly are intended to teach how to avoid „dying as a consequence of flying“.

There are many other hobbies where the risk of dying is much higher, I guess :)

The particular scenario you asked about is very unlikely, and there are quite a few other scenarios more plausible that have some risks associated with them. However, and that’s the important bit, risk mitigation is something that is trained right from the start, so if you’re interested, then go for it - simply make sure you get decent training, develop your competence and make safety a habit!