From the opening post sounds like a storm in a teacup (apologies if it is more serious) like not paying a fee, not doing something on the ground they wanted you to do, etc. If that is the case I doubt they have any authority to require any aircraft pretty much anywhere in the world to do anything once it has departed. Of course they can make a report to the authorities and can persue a civil action if money and or damage is involved, but once in the air I would be inclined to agree with earlier posters, the only authority is the Government of the State concerned, who can order any aircraft to land, and presumably order them to land anywhere, as long as it doesnt endanger the aircraft.
A good line to remember in such circumstances is something along the lines of “under whose authority are you giving this order, and under which regulation”?
lmsl1967 wrote:
can an ATC order a PIC to return to the airport
Well, maybe not directly, but in my understanding, in CAS they can technically give you a clearance that gets you on the ground on the runway, and deny you any other clearance. That effectively forces you to return to the airport.
due to alleged fail to comply with their instructions?
Whether they can do it for this reason is a different question. I don’t know, but my gut feeling is that I doubt that case has been “thought of” in the write up of their powers and instructions, so I expect nothing makes it their job to do so. I expect all they can do is a report. AFAIK their job is to ensure safety, expeditious flow of traffic, etc. So calling you “back” for not following their instructions is not part of their job and could be abuse of authority.
what_next wrote:
Peter wrote: BTW if you are intercepted and refused entry into UK airspace, but would run out of fuel otherwise, what is the correct procedure?I wouldn’t know how that works because the international protocol for interceptions does not have “refusal of entry” as an option. There is no way a fighter pilot could signal that to an intercepted aircraft in unambiguous way.
My understanding is that an intercepting aircraft will try to talk to you over radio. They can easily convey that over radio. Unless you have an electrical/radio failure… or you are an ultralight / vintage aircraft flying without radio :)
Interesting question… I had an experience on the controlled airport where I had a problem with the radio after my take-off clearance see post here
When radio contact was re-established I was threatened of being ordered to come back and land. I must say I was surprised that this could be done by ATC but I was not going to continue the dispute over the tower frequency….
I would also believe that they can provide or deny clearance and that if you do not comply you should have a good explanation (emergency, for safety of flight,…) but that they can not order you to land. Obviously I am interested should someone else have another opinion.
ATC could certainly tell you that you do not have a clearance to fly onwards (issuing a “clearance limit” is standard phraseology here in the UK, in Class G 
) but what would that achieve? You would just exercise the captain’s authority to protect the safety of the aircraft and continue with the flight. You could tell them directly, or you could create some useful ambiguity in your replies (“G-XXXX request radio check”) until you are close to the CAS boundary, or better still close to the border with another country and then they can’t do anything. Just because ATC have witheld a clearance would not IMHO force most aircraft on the ground.
I have never heard of the situation in the OP, but at the same time I am sure most PPL holders would obey any instruction from ATC, short of one telling them to fly into the ground. The training system ensures pilots are scared of ATC.
Also I don’t see how the international interception procedure works in IMC – what are the possible rules of engagement in peacetime? The interceptions we read about are nearly all on airliners which flew out of the last station’s range, but at FL300+ they are nearly always VMC. This is anyway digressing…
Peter wrote:
Also I don’t see how the international interception procedure works in IMC – what are the possible rules of engagement in peacetime?
Is an IMC intercept really impossible? This FAA doc mentions night and IMC intercepts. Military aircraft certainly fly in formation in IMC.
jfw wrote:
I was not going to continue the dispute over the tower frequency….
That’s an interesting and probably more relevant point than all the discussion on the exact rules. At the end of the day, you want to defuse the situation. Coming back to land is pretty drastic, but if it’s a choice between that and an ongoing vendetta with an airfield that you perhaps rely on, I would probably land back and talk it over.
The training system ensures pilots are scared of ATC
That may be true in certain places/countries/airspaces but it certainly isn’t a global truth. In fact I’d not be surprised if it turned out to be just another UK oddity.
I was always thought ATC was there to help.
Ref’ interception in IMC, John Cunningham and “Jimmy” Rawnsley managed it in 1943, holding short of the blip until they broke cloud to make a visual identification before opening fire. I’m reading Rawnsley’s book Night Fighter this week and very good it is too.
Peter wrote:
The training system ensures pilots are scared of ATC.
Another “No” vote to that! At our place we try to visit the control tower with the students to show them what the evil controllers look like in real life
Maybe “scared” was putting it too strongly, but I am sure everyone knows exactly what I meant. Private pilots are taught to take ATC very seriously. This theme is repeated everywhere, including many posts here by others. The whole issue of keeping decisionmaking in the cockpit (or not) is wrapped up with many fatalities, too.
There is also the matter raised by jwoolard in post #15 i.e. not obeying ATC could get you kicked off your airfield. For many pilots, especially owners, that is the end of their flying, due to the distance they have to drive. Airfield politics tends to be the overriding factor anywhere near your base.
