PPL » Air Law (A) & (H) » Clearances
4.62.2 State the requirements for complying with ATC clearances and instructions. CAR 91 & AIP ENR
91.241 Compliance with ATC clearances and instructions
(a) A pilot of an aircraft operating in a control area or control zone designated under Part 71 must—
(1) except when manoeuvring in accordance with an ACAS resolution advisory or a GPWS or TAWS alert, comply with any ATC clearance or instruction issued by the ATC unit responsible for the control area or control zone; and
(2) when a deviation from an ATC clearance or instruction is required for the safe operation of the aircraft, notify ATC of the deviation as soon as possible.
(b) A pilot of an aircraft need not comply with an ATC clearance or instruction if compliance would cause the pilot to breach any rule in this Part.
(c) A pilot of an aircraft who elects not to comply with an ATC clearance or instruction under paragraph (b) must immediately notify the appropriate ATC unit of the non-compliance.
AIP ENR 1.1-12
8 ATC CLEARANCES
8.1.1 CAR 91.245 and 91.247 prescribe that airspace in which an ATC clearance is required. Rule 91.225 prescribes the requirements for ATC clearances when operating at an aerodrome where ATC is in attendance.