AIP ENR 1.2
By day, when visual meteorological conditions (VMC) do not exist, the ATC unit responsible for a CTR may authorise, at pilot request, a special VFR flight in the CTR, or in a CTA next to the CTR for the purpose of entering or leaving the CTR, provided that (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 800 m (for helicopters)
- a helicopter will be operated at such a speed that the pilot has adequate opportunity to observe any obstructions or other traffic in sufficient time to avoid collisions
- the flight can be conducted in accordance with the requirements of CAR 157 with regards to low flying.