Special VFR
By day, when VMC do not exist, the ATC unit responsible for a control zone may issue, at pilot request, a special VFR clearance for flight in the CTR, or in controlled airspace next to the CTR for the purpose of entering or leaving the CTR, providing
(AIP ENR 1.2):
- the special VFR flight will not unduly delay an IFR flight
- the flight can be conducted clear of cloud
- the visibility is not less than
- 1600 m for aeroplanes
- 800 m for helicopters
- for balloons, not less than 100 m below 500 ft AGL and 1600 m at and above 500 ft AGL
- a helicopter is operated at such a speed that the pilot has adequate opportunity to observe any obstructions or other traffic in sufficient time to avoid collisions and
- the flight can be conducted in accordance with the requirements of CAR 157 regarding low flying.