Document ID: chunk:federal_register_of_legislation:F2006B07622:body:0:p2
Version: federal_register_of_legislation:F2006B07622
Segment Type: other
Provision Reference: 
Character Range: 2840–6023

visual cues exists, immediately request priority handling from Air Traffic Control (ATC) to facilitate a route or an altitude change to exit the icing conditions:

                  1. Unusually extensive ice accumulation on the airframe and windshield in areas not normally observed to collect ice.

b.        Accumulation of ice on the lower surface of the wing aft of the protected area.

c.         Accumulation of ice on the engine nacelles and propeller spinners farther aft than normally observed.

              Since the autopilot, when installed and operating, may mask tactile cues that indicate adverse changes in handling characteristics, use of the autopilot is prohibited when any of the visual cues specified above exist, or when unusual lateral trim requirements or autopilot trim warnings are encountered while the airplane is in icing conditions.

              All wing icing inspection lights must be operative prior to flight into known or forecast icing conditions at night. (NOTE: This supersedes any relief provided by the Master Minimum Equipment List)."

              3.        Revise the CAAC and FAA-approved AFM by incorporating the following into the Normal Procedures Section of the AFM:

                            "THE FOLLOWING WEATHER CONDITIONS MAY BE CONDUCIVE TO SEVERE IN FLIGHT ICING

                  1. Visible rain at temperatures below 0 degrees Celsius ambient air temperature.

b.        Droplets that splash or splatter on impact at temperature below 0 degrees Celsius ambient air temperature.

PROCEDURES FOR EXITING THE SEVERE ICING ENVIRONMENT:

              These procedures are applicable to all flight phases from takeoff to landing.

Harbin Y12 Series Aeroplanes

 AD/Y12/8 (Continued)

              Monitor the ambient air temperature. While severe icing may form at temperature as cold as -18 degrees Celsius, increased vigilance is warranted at temperatures around freezing with visible moisture present. If the visual cues specified in the Limitations Section of the AFM for identifying severe icing conditions are observed, accomplish the following:

                  1. Immediately request priority handling from Air Traffic Control to facilitate a route or altitude change to exit the severe icing conditions in order to avoid extended exposure to flight conditions more severe than those for which this airplane has been certificated.

b.        Avoid abrupt and excessive manoeuvring that may exacerbate control difficulties.

c.         Do not engage the autopilot.

d.        If the autopilot is engaged, hold the control wheel firmly and disengage the autopilot.

e.         If an unusual roll response or uncommanded roll control movement is observed, reduce the angle-of-attack.

f.          Do not extend flaps when holding in icing conditions. Operation with flaps extended can result in a reduced wing angle-of-attack, with the possibility of ice forming on the lower surface further aft on the wing than normal, possibly aft of the protected area.

                 g.        If the flaps are extended, do not retract them until the airframe is clear of ice.

                h.    Report these weather