During some general aviation flights, pilots can plan a flight rule change in their flight plan. When one part of the flight is going to be conducted in IFR and the other one in VFR, or the other way round, pilots must inform the appropriate ATS (Air traffic services).
Pilot shall use Y or Z flight rules to specify this special situation.
Y flight rules means that the first part of the flight is IFR, thereafter the flight is conducted in VFR.
Z flight rules means that the first part of the flight is VFR, thereafter the flight is conducted in IFR.
In summary, the letters will denote the category of flight rules which the pilot intends to comply:
The pilot should specify in the appropriate route item the point or points where that change of flight rules is planned.
Where there is more than one change in the type of flight rules, the code to be used is to reflect the first rule, i.e., use "Z" for VFR/IFR/VFR.
When the Flight Rule is Y, then the IFR route has to be filled until the last IFR point.
MAG UZ20 MOSEK VFR DCT
This means the flight will depart IFR and remain IFR till MOSEK, after MOSEK the flight will continue VFR
When the Flight Rule is Z, then the VFR route has to be filled until the first IFR point.
KLF DCT TADUV/N0280F140 IFR T172 DEJAB L665 TOK
This means the flight will depart VFR and remain VFR till TADUV, after TADUV the flight will continue IFR at FL140 with true airspeed 280 Knots.
A pilot can change his flight plan and his flight rules during his flight. This must be negotiated with the air traffic controller.
The controller shall prescribe conditions and/or limitations with respect to the submission of flight plans during the flight to ATC units.
A pilot electing to change the conduct of his flight from compliance with the instrument flight rules (IFR) to compliance with the visual flight rules (VFR) shall:
- notify the appropriate air traffic services unit specifically that the IFR flight is cancelled
- communicate thereto the changes to be made to his current flight plan
The change from an instrument flight rules (IFR) flight to a visual flight rules (VFR) flight is only acceptable when a message initiated by the pilot-in-command containing the expression "CANCELLING MY IFR FLIGHT", together with the changes from IFR flight to VFR flight, is sent.
No reply, other than the acknowledgement "IFR FLIGHT CANCELLED AT", should normally be made by the controller.
When the controller knows that instrument meteorological conditions are likely to be encountered along the route, a pilot changing from IFR to VFR flight shall be advised: "INSTRUMENT METEOROLOGICAL CONDITIONS REPORTED (or FORECAST) IN THE VICINITY OF ".
The pilot in command has the responsibility to maintain VMC along his remaining route.
An ATC unit receiving notification of an aircraft's intention to change from IFR to VFR flight shall inform the next controllers to whom the IFR flight plan was addressed for the remaining route. (On the IVAO network, only the next ATC should be informed as there is no flight plan following along the route).
A pilot operating in accordance with the visual flight rules who wishes to change to compliance with the Instrument Flight Rules shall:
- communicate the necessary changes to be effected to his current flight plan
- submit a flight plan to the air traffic services unit and obtain a clearance prior to proceeding IFR when in controlled airspace
This change (from VFR to IFR flight rules) should be asked when the pilot suddenly faces bad weather conditions below VFR minima in order to continue his flight.
If your flight plan is IFR and you want to take off from a non-controlled and non IFR airfield, you can make a VFR departure under VMC conditions from this airfield. When climbing to your first route point, you shall call the en-route controller (if connected) in order to get your IFR clearance in the air.
The en-route controller can only give IFR clearance to an aircraft above MRVA. The MRVA is the lowest altitude or flight level that may be assigned by a radar controller to an IFR aircraft.
The pilot shall climb to a safe altitude as soon as possible like the minimum sector altitude if published, or the minimum en-route altitude applicable at the first en-route point.
We recommend calling the en-route controller before take-off in order to negotiate the first contact point and altitude.