ICE AND RAIN PROTECTION
Operation
Aircraft Operations Manual
11.2
PAGE
10
Jun 01/19
CONDITIONS
NORMAL PROCEDURES
2.10 SUPERCOO-
LED LARGE
DROPLETS
(SLD)
Identification of Supercooled Large Droplets (SLD)
Substantial ice build
−
up on the spinner, further aft than normally observed,
might be an identification of SLD. If observed, increase scanning of the wing. If
accumulation of ice on the upper surface aft of the boots is observed, exit the
area with these conditions immediately to avoid extended exposure.
If the autopilot is engaged, hold the control wheel firmly and disengage the auto-
pilot. Keep the autopilot disengaged until the upper wing surface is free from
ice.
If an unusual roll response or uncommanded roll control movement is ob-
served, decrease the angle of attack.
For operators under the FAA legislation, triggers for being in SLD conditions are
either substantial ice buildup on the spinner, further aft than normally observed
and/or ice accumulation on the wing upper surface, aft of protected surface.
NOTE
2.11 VISUAL CUE
OF ICE
ACCUMU
−
LATION
Visual cue of ice accumulation
The windshield wiper arms give a visual cue of ice accumulation, although air-
frame ice can be present without any build
−
up on the wiper arms. Even though
the wiper arms are the primary visual cue, accumulation of ice shall be moni-
tored on all visible surfaces.
2.12 STALL WARN-
ING SYSTEM
With Mod. No. 3529 for
340B / 3530 for 340WT
(Improved stall warn-
ing system for icing
conditions)
With either of the Engine Anti
−
ice switches selected ON
, the improved stall
warning system, with increased stall warning speed trigger levels, will be
armed
if on ground, and
activated
in the air.
However,
activation is inhibited
until approximately 6 minutes after lift
−
off.
The activation is indicated by illumination of a blue ICE SPEED p/b on the cen-
ter instrument panel.
The increased stall warning level can be deactivated
−
After the engine anti
−
ice system has been switched OFF
and;
−
There is no ice observed on any part of the aircraft and it is certain that there
is no ice accumulated on the aircraft.
(Cont’d)