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What if ATC deny an "avoid due to wx" because of military airspace?

This is a different topic (Farnborough is not military) but Farnborough have for many years been asking traffic passing near at say 2200 or 2300ft to climb to 2400ft, for spacing for bizjet traffic. They have always (IME) done it politely, and of course you can decline. Nowadays, with the new CAA bust-them-all CAS bust policy, I would like to get the radio recorded before climbing to 2400ft, but I have stopped flying around that “2500ft LTMA” area anyway because it is way too risky. 10 secs on some Gatwick radar trace, in CAS, and you are busted regardless of what comms you have with Farnborough.

This is where I got the transit through the military area on the way back (they gave me a new squawk which looks like it broke the tracking)

The tracking for the original flight to LFSB shows nothing of note. I am sure the locals will know the area I am referring to. This is the track

Shoreham EGKA, United Kingdom


The big difference for ATC between VFR and IFR (airspace dependant) is that the ATCO is responsible for the separation of traffic.
The most usual form of military airspace is Delta, that is non-classified airspace →ATCO can’t separate IFR traffic in an airspace he/she can’t control and is unaware of the traffic flying there. That is why they are always very reluctant to even coordinate a cross of military airspace. Moreover, inside this airspace there might be +40 aircraft flying from 80kts to supersonic between 5000ft AGL and FL500 so if a “non-player” enters the Delta airspace the mission commander will call “knock it off” and the 40 aicraft will have to stop manouvering and fly a pre-briefed contingency plan.

Nevertheless, the PIC is the authority on board and his/her first priority is safety so if he decides to go inside a military airspace he should first notify and manouver as needed, squawking 7700 if necessary so mil ATCO can also pass the information to the military aicraft even before he receives it from his civilian colleague. Of course a report will be made but as I stated before, safety is paramount.


Don't get too slow

OK; this makes sense, especially for the 7700.

However, we now move to practicalities. Does Europe actually have 40 (forty) functioning military aircraft? I say this only slightly tongue in cheek. I have been told by German pilots (and recall such posts here) that Germany has barely single digit number of airworthy fast jets.

Shoreham EGKA, United Kingdom

Doesn’t matter. They have joint exercises with air forces from all over the world. Especially the Germans !

EBST, Belgium

Peter wrote:

If you are VFR in CAS then the “avoid wx” situation is the same as IFR in CAS

In Norway they tend to be pretty high, and in in controlled airspace almost all of them, so VFR or IFR makes no difference. Still there are other differences. Last fall we had these huge NATO maneuver. Then huge airspaces were closed all to the ground. I mean prohibited, “no-fly” under any circumstance. I don’t know what would happen if you flew into one of those, no one tried AFAIK

You can meet low flying military aircraft (down to 200 fr) at any time and any place though. They fly wherever they want, whenever they want. See and be ween is the only rule, but some of them got some fancy radars I guess


Peter wrote:

If you are VFR OCAS then ATC has no obligation beyond the ICAO FIS.

And the situation is exactly the same for IFR. (At least in class G airspace. In class F it is different.)

ESKC (Uppsala/Sundbro), Sweden

The interesting thing here is that ATC have less ability to grant an avoid due to wx if it goes into military airspace. But they still have to do it. It means more work for them.

I guess the bottom line is that they are likely (in some places, evidently) to make you press a lot harder.

Shoreham EGKA, United Kingdom

If you are VFR OCAS then you have no assurance of getting a CAS transit, to avoid wx or for any other reason. If you are VFR in CAS then the “avoid wx” situation is the same as IFR in CAS.

I dont see the difference?

An alteration due to weather is a request in either circumstances, although not a required request if OCAS, unless taking you into CAS. It surely can be denied (for example if it would result in a loss of seperation with other traffic) but there is always an expectation of an alternative contract being negotiated. Ultimately a pilot may well declare an emergency if all else fails.

OCAS the pilot may require a course that penetrates CAS or a military zone, and, in the same way, I think there is an expectation that AT will co-ordinate, obtain a clearance, squawk and handover. In my experience they do, and I cant think of a good reason why they wouldnt. In any case, the pilot has the same option of declarinng an emergency.

I also dont see why the pilots expectation at the start of a flight should be any different? The expectation is to complete the trip, in the case of a flight in CAS or OCAS it may well end up not being as filed or planned, but ATC are there to do their best to expedite the flight and provide the required clearances (of course a clearance through CAS may not be granted, and, in the same way, a clearance as filed may be denied).

The pilot is the only person that can decide whether a “diversion” due to weather is necessary; ATC are not in the cockpit. This is a primary command function and I think there should be no doubt in a pilot’s mind that the option is available, albeit it is up to ATC to provide all the necessary information in order for the pilot to make a judgement – for example, request 20 degrees left, aha, I have high speed military traffic in that sector not working me, unable, might leave you wanting to explore an alternative diversion. The answer surely must always be if you are going to grant me that heading to avoid weather, why not? I would be surprised if AT did not give an answer, and, perhaps, reflect on the answer if it was clearly in inadequate excuse, given there is now a record on the tape.

Last Edited by Fuji_Abound at 12 Sep 09:13

I guess ATC can accommodate pilot requests as long as you explicitly tell them you need XXXX and from then you will maintain your own traffic/terrain separation and they own airspace (if you deviate from planned IFR route/level), as you can’t have your “change of route/level” request accepted and expect them to bear traffic/terrain responsibility

In the other hand, they may not be able to clear you to others airspace (if that takes you out of your accepted IFR route/level)? or you are probably talking to the wrong person? for clearance to nearby airspace and terrain/traffic separation outside your assigned IFR route/level you are expected to just fly as any VFR flies…

ESSEX, United Kingdom

I think the reason ATC can be reluctant to allow an avoid into mil airspace is because they don’t “own” it.

In France, I have been told by French pilots, the military own all the air as a default position and allow civilian traffic use it. I don’t how it works in other countries.

Shoreham EGKA, United Kingdom
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