PPL » Air Law (A) & (H) » Airspace
4.75.2 State the rules pertaining to operating VFR in the various classes of airspace. CAR 91 & AIP ENR
91.245 Operations in controlled airspace
(a) Except as provided in paragraphs (e) and (f), a pilot-in-command of an aircraft must not enter a control area or control zone designated under Part 71 unless the pilot-in-command obtains an ATC clearance to enter the control area or control zone.
(b) A pilot-in-command of an aircraft operating in Class A airspace must—
(1) operate the aircraft under IFR; and
(2) unless otherwise authorised by the ATC unit responsible for the class A airspace, maintain two-way communications with that ATC unit on the appropriate frequency.
(c) A pilot-in-command of an aircraft that operates in the following classes of airspace must maintain two-way radio communications with the ATC unit responsible for the airspace concerned on the appropriate frequency unless otherwise authorised by the ATC unit:
(1) Class B, C, or D airspace:
(2) Class E airspace under IFR.
(d) If different classes of airspace adjoin one above the other, a pilot operating at the common level may comply with the requirements of the less restrictive class of airspace.