Class F airspace entry rules

Class F airspace (restricted, advisory, danger) has its own entry rule per type (TC AIM RAC 2.8.6.1). Code decode (CYA113(A)): class-f-id-code.

Class F basics (RAC 2.8.6):

• Fourth category: military operations areas.
• Can be controlled, uncontrolled, or a mix of both.
• Unless stated otherwise, surrounding airspace's rules apply (CAR 601.04; RAC 2.8.6).
• Designated in the Designated Airspace Handbook (TP 1820). Restricted and advisory areas charted on HI or LO, as applicable, and VFR charts (RAC 2.8.6.1).

Altitudes (RAC 2.8.6.1):

• All Class F altitudes inclusive unless otherwise indicated.
• "below" or "above" before an altitude = that altitude NOT included.

Restricted (CYR):

• Entry needs authorization from the user agency (person named in the DAH). May delegate to a controlling agency, often ATC (CAR 601.04(2)).
• Definition: airspace of defined dimensions above land or territorial waters, flight restricted per specified conditions, designated for safety purposes (RAC 2.8.6.4).
• User agency must be identified for restricted airspace, and where possible advisory (RAC 2.8.6.4).
• NOTAM-only designation only for a relatively short, specified period (hours or days), issued at least 24 hours before activation (RAC 2.8.6.6).

Advisory (CYA): activity may be under way, enter with caution (RAC 2.8.6.3).

• Avoidance encouraged, not required. Non-participating pilot may enter at own discretion, with extra vigilance.
• Participating aircraft and pilots flying through are equally responsible for collision avoidance.
• ATC normally keeps IFR aircraft in controlled airspace 500 ft vertically clear of an active advisory area, or 1 000 ft where wake turbulence minima apply.
• Pilots encouraged to monitor an appropriate frequency and broadcast intentions; 126.7 MHz if uncontrolled.
• Military operations in Class F airspace may use UHF-only communications (RAC 2.8.6.3 Note).

Danger, international waters (CYD): hazardous activity (RAC 2.8.6.2).

• ATC will not clear a non-participating flight in. Avoid unless taking part.
• Distinct from the DAH-designated danger area over Canadian land/territorial waters (airspace-structure).

ATC separation (RAC 2.8.6.1): ATC keeps IFR traffic clear of active Class F airspace, unless pilot:

• states user-agency permission was obtained, or
• holds an altitude reservation approval (ALTRV APVL), or
• is cleared for a contact or visual approach.

Joint-use airspace: Class F where the controlling agency may authorize other traffic whenever user agency isn't using it (RAC 2.8.6.5).

Not a NOTAM restriction:

• NOTAM can also close airspace over a forest fire (CAR 601.16, prohibited by CAR 601.15(b)), or wherever the Minister deems necessary for safety or security (Aeronautics Act s.5.1).
• Neither is Class F restricted: unclassified airspace closed by notice (RAC 2.8.6.4).

Trap: forest-fire or s.5.1 NOTAM isn't Class F, no CYR code, not "restricted airspace"; CYD (international waters, ATC won't clear you in) is Class F, domestic DAH danger area (airspace-structure) is not.

Practice