reference gents:
QCAR - OPS 1.230 - Instrument departure and approach procedures
(a) An operator shall ensure that instrument departure and approach procedures
established by the State in which the aerodrome is located are used.
(b) Notwithstanding subparagraph (a) above, a commander may accept an ATC
clearance to deviate from a published departure or arrival route, provided
obstacle clearance criteria are observed and full account is taken of the
operating conditions. The final approach must be flown visually or in
accordance with the established instrument approach procedure.
(c) Different procedures to those required to be used in accordance with
subparagraph (a) above may only be implemented by an operator provided
they have been approved by the State in which the aerodrome is located, if
required, and accepted by the Authority.