When in Doubt
1.01 Frost, ice or snow on top of deicing or anti-icing fluids
(1) is not considered as adhering to the aircraft and a take-off may be made.
(2) must be considered as adhering to the aircraft and a take-off should not be attempted.
(3) is only considered as adhering to the aircraft when Vr speeds are below 100 kt.
(4) is not considered as adhering if the aircraft has been de-iced and then anti-iced.
Reference: WID (When in Doubt) Page 52 #77 Frost, ice or snow on top of deicing or anti-icing fluids must be considered as adhering to the aircraft and take-off must not be attempted.
1.02 Where conditions are such that frost, ice or snow may reasonably be expected to adhere to the aircraft, no person shall take-off or attempt to take-off in an aircraft unless...
(1) it has been de-iced.
(2) it has been inspected immediately prior to take-off to determine whether any frost, ice or snow is adhering to any of its critical surfaces.
(3) its skin temperature is warm enough to ensure that adhering frost, ice or snow will slide off on take-off.
(4) its power and runway length are sufficient to allow acceleration to Vr plus 10% before rotation.
Reference: CARS 602.11 page 452The aircraft has been inspected immediately prior to take-off to determine whether any frost, ice or snow is adhering to any of its critical surfaces.
1.03 Prior to take-off, the PIC cannot confirm that the aircraft is "clean". Take-off
(1) may be commenced provided the maximum holdover time has not been exceeded
(2) may be commenced provided the anti-ice fluid used was of the type that prevents ice or snow from sticking to the critical surfaces.
(3) may be commenced provided the amount of frost, ice, or snow does not exceed that specified in the company operations manual.
(4) must not be attempted until confirmation is obtained that the aircraft is clean.
Reference: WID Page 14 Therefore, if the Pilot-in-Command (PIC) cannot confirm that the aircraft is ―clean, takeoff must not be attempted until confirmation is obtained that the aircraft is free of frozen contaminants. This is called the “Clean Aircraft Concept.”
4. One engine is kept running during a quick turn around in icing conditions because you are unable to restart it with existing internal or external power. When taxiing for take-off, you are advised that there is a significant amount of wet snow on the aircraft. As your operating instructions require both engines to be shut down for deicing, you should...
(1) take off but delay rotation until Vr plus 10%.
(2) take off as wet snow will slide off as the aircraft becomes airborne.
(3) taxi back to the apron, shut down the engine you are able to restart and have the critical surfaces carefully de-iced.
(4) cancel the flight until proper equipment is available or necessary repairs made.
Reference: Cancel the flight.
1.05 The only positive assurance that an aircraft is "clean" prior to take-off can be achieved by
(1) confirmation from the crew chief that the fluid used has the required holdover time.
(2) ensuring the aircraft is not subjected to excessive ground delays.
(3) close inspection by the PIC or designated flight crew member.
(4) ensuring take-off is within the applicable holdover time table.
Reference: WID P.52 #74Pre-Take-Off Contamination Inspection: As required by regulations, immediately prior to take-off, a pre-take-off inspection shall be made to determine whether frost, ice or snow is adhering to any of the aircraft critical surfaces, except where the operator has established a program in accordance with GOFR 622.11 and complies with that program. The pilot may need the assistance of qualified personnel to perform this inspection.
1.06 Who may inspect an aircraft immediately prior to take-off to determine whether any frost, ice or snow is adhering to any of its critical surfaces?
The PIC and
A. a flight crew member of the aircraft designated by the PIC to carry out the inspection.
B. the operations officer.
C. the deicing crew.
D. a person designated by the operator who has received the required surface contamination training.
E. any Aircraft Maintenance Engineer.
(4) A, D.
Reference: CARS 602.11.5 The inspection referred to in subparagraph (4)(a)(i) shall be performed by
(a) the pilot-in-command;
(b) a flight crew member of the aircraft who is designated by the pilot-in-command; or
(c) a person, other than a person referred to in paragraph (a) or (b), who (i) is designated by the operator of the aircraft, and (ii) has successfully completed training relating to ground and airborne icing operations under Subpart 4 or relating to aircraft surface contamination under Part VII.
1.07 When a crew member of an aircraft observes frost, ice or snow adhering to the wings of an aircraft before take-off, the crew member
(1) shall immediately report that observation to the PIC.
(2) need not report that observation if the aircraft has recently been de-iced.
(3) shall immediately report that observation to the designated crew member.
(4) unless designated, need not report that observation.
Reference: CARS 602.11.6 Where, before commencing take-off, a crew member of an aircraft observes that there is frost, ice or snow adhering to the wings of the aircraft, the crew member shall immediately report that observation to the pilot-in-command, and the pilot-in-command or a flight crew member designated by the pilot-in-command shall inspect the wings of the aircraft before take-off.
1.08 Before commencing take-off the PIC is advised that there is frost, ice or snow adhering to the wings of the aircraft.
(1) may take off without a further wing inspection if the aircraft has been recently de-iced.2.
(2) shall request a go/no go decision from company operations.
(3) shall request the deicing crew to inspect the wings before take-off.
(4) or another flight crew member designated by the PIC shall inspect the wings before take off.
Reference: CARS 602.11.6 (2) No person shall conduct or attempt to conduct a take-off in an aircraft that has frost, ice or snow adhering to any of its critical surfaces.