The AFM is likely more limiting on this subject.
From the CL-604 AFM Limitations Section:
3. OPERATION IN ICING CONDITIONS
During cold weather operations, the flight crew must ensure that the airplane fuselage, wings and tail surfaces are free from ice, snow or frost.
From the LR-60 AFM Limitations Section:
...requirement to assure that all critical surfaces of the airplane
(wing, vertical and horizontal stabilizers, flight control surfaces,
spoilers and flaps) are
free of frost, ice and snow for takeoff.
HS-125 was a little more agreeable, though: (This is several years old and may no longer be accurate).
�� The aircraft must be clear of snow, ice, and frost before
takeoff, with the exception of the following areas.
– Frost is allowable on underside of wings over the general
area of fuel tanks provided that the depth does not
exceed 0.125 inch (3 mm). If frost is present in this
region, the WAT limited takeoff weight must be reduced
by 1,000 lb (454 kg) and the net flight path reference and
fourth segment climb gradients must be obtained using a
weight 1,000 lb (454 kg) higher than the actual weight.
– Frost is allowable on the fuselage provided the layer is
thin enough to distinguish the surface features such as
paint lines or markings underneath, but all vents, probes,
and ports must be clear of frost.
Anyone ever actually polished frost? Do FBO's have Hand-Buffers available?
