I’ve come across a couple of times recently where ATC can’t “invite” you to do something but could agree it to if you ask.
1) Special VFR. I had departed from the zone VFR, the weather deteriorated and when calling for return was informed that the airfield was now IFR. While I could have requested an instrument approach, I asked for Special VFR which was granted. Apparently it can’t just be offered.
2) Cancelling IFR. Pilots can elect to cancel IFR anytime and downgrade to VFR (if not in Class A airspace), but ATC can’t ask or instruct them to do so. This is not the same as being cleared for a Visual Approach when IFR.
Is this an exhaustive list? I’m sure I must have overlooked something.
ad 1) here in the US ATC cannot offer SVFR, you have to request it AND do so outside their control zone. This quite often throws pilots at my base (Class D), as SVFR conditions are a pretty regular occurrance here.
ad 2) again in the US, ATC do sometimes ask if you’d like to cancel, however AFAIK they cannot force you to do so
One more example would be the contact approach, which can also be requested only by the pilot. Not sure if that exists in Europe.
I had the impression IFR visual approach is just like SVFR you need to ask? I would add landing or take on opposite runway, opposite circuit, opposite approach, omni departures? and switching lights OFF at night
Also checking if customs want to see you 
172driver wrote:
ad 1) here in the US ATC cannot offer SVFR, you have to request it AND do so outside their control zone. This quite often throws pilots at my base (Class D), as SVFR conditions are a pretty regular occurrance here.
How does it work if you want to depart SVFR if you have to request it outside the control zone (I assume you mean “airspace associated with an airport that extends to the ground”). How does it work if you enter the “zone” in VMC, but conditions deteriorate so that you need Special VFR?
Ibra wrote:
I had the impression IFR visual approach is just like SVFR you need to ask?
ATC can initiate visual approaches by asking the pilot to “REPORT THE FIELD IN SIGHT”. If the pilot doesn’t want a visual approach, then (s)he simply never reports the field in sight. :-) But it would of course make life easier if the pilot stated at once that (s)he wants an instrument approach.
ATC cannot cancel IFR for you but they can make it impossible for you to continue with the flight unless you cancel IFR e.g. to descend below some bad wx.
Airborne_Again wrote:
How does it work if you want to depart SVFR if you have to request it outside the control zone (I assume you mean “airspace associated with an airport that extends to the ground”). How does it work if you enter the “zone” in VMC, but conditions deteriorate so that you need Special VFR?
If the surface controlled airspace is not VFR, you must obtain a clearance prior to entry. If you are already on the ground, you request the SVFR clearance before taxi. SVFR is one-in one-out type operation where the aircraft that has the clearance is expected to enter and land or exit and depart the airspace. We would often use SVFR when smoggy and below 3 SM, but no clouds and climb up to the smog layer top and cancel SVFR, usually 1000 to 2000 MSL. Also, before our towered airport got instrument approaches, we would fly the ILS to the nearby airport, and request SVFR once we were underneath the bases.
Airborne_Again wrote:
How does it work if you want to depart SVFR if you have to request it outside the control zone
On the ground you ask the tower. If untowered the controlling agency (e.g. the control tower of a class C airport if your untowered airport lies underneath their airspace).
In the air you have to be outside the (in my case) Class D. Leads to some hilarious exchanges on the radio when the tower controller – who is not allowed to suggest it – tries to explain to a pilot that he must tun around, fly a few miles, request SVFR and come back.
Peter wrote:
ATC cannot cancel IFR for you but they can make it impossible for you to continue with the flight unless you cancel IFR
How so?
How about every crossing of CAS in VFR? You need to ask for it to get a permission. Since you’re not in contact with the airspace owner in most cases while VFR, ATC cannot invite you to cross their airspace if you like. You need to ask.
172driver wrote:
How so?
By not giving you the IFR clearance you need. Sometimes this is forced on ATC by regulations. E.g. you can’t be cleared IFR below the minimum vector altitude unless you’re on an official approach. That’s pain if you need to do a cloud break to an airport without an IAP and the MVA is higher than the minimum IFR altitude.
