Icing bans: ground contamination & route icing
Two rules, two triggers:
| Rule | Trigger | Ban | Lifted when |
|---|---|---|---|
| Ground (CAR 602.11(2)) | Frost, ice, or snow adhering to any critical surface | No takeoff | Never for "thin enough to blow off"; only the exceptions below |
| Route (CAR 605.30) | Icing conditions reported or forecast along the route | No takeoff or continued flight | (a) PIC determines aircraft adequately equipped for icing conditions, to the airworthiness standards its type certificate was issued under; or (b) current weather reports or pilot reports show icing conditions no longer exist |
Ground rule details:
- Cold-soaked fuel exception: frost from cold-soaked fuel on wings allowed if takeoff follows manufacturer's instructions for it (602.11(3)).
- Crew duty: any crew member seeing frost, ice, or snow on wings before takeoff must report immediately to pilot-in-command; wings then inspected before takeoff (602.11(6)). Who may inspect:
aeronautics/pre-takeoff-contamination-inspection. - "Ice" defined (CAR 101.01(1)): water frozen on a surface. Includes:
- black ice
- compacted snow turned to polished ice surface
Hoar frost exemption (TP 10643):
| Aircraft | May take off with hoar frost | Condition |
|---|---|---|
| No rear-mounted engines | On fuselage only | Manufacturer's instructions approve it |
| Rear-mounted engines | Same (separate exemption to CAR 602.11(1) and (2)) | Hoar frost not mixed with any other contaminant |
Trap: icing reported or forecast along the route is CAR 605.30; ice already on the airframe on the ground is CAR 602.11. Swapping them (e.g. "no icing exception" answer for a route-forecast question, or vice versa) is the wrong rule.
References
- CAR 602.11(2) (no takeoff with frost, ice, or snow on a critical surface)
- CAR 602.11(3) (cold-soaked fuel exception)
- CAR 602.11(6) (crew report and inspection duty)
- CAR 101.01(1) (definition of "ice")
- CAR 605.30 (icing conditions reported or forecast along the route)
- TP 10643 (When in Doubt... Small and Large Aircraft)