Page 20 - Oct24

AVIATION ISSUES
What Can You Do?
= When operating in icing conditions, use
the autopilot only as directed by checklists and aircraft manuals, which might call for periodically disconnecting the autopilot to better feel changes in the handling qualities of the aircraft.
= Maintain the recommended airspeed for flight in icing conditions as specified in the POH.
= Activate leading-edge deice boots and pitot heat in accordance with the POH.
= While icing conditions exist, continue to manually cycle the deice system unless the system has a provision for continuous operations.
= Review your POH for specific operational requirements to determine the most effective means of shedding ice.
= Closely monitor windshield, windshield wiper, engine air inlets and wings for ice accumulation, and do not hesitate to leave icing conditions as soon as possible to avoid ice accumulation.
= Be aware of the potential for icing conditions and use all checklists associated with operations in such conditions.
Source: National Transportation Safety Board
Deicing Safety Alert
The National Transportation Safety Board issued Safety Alert SA-097 ahead of winter in the Northern Hemisphere, reminding operators that flying in icing conditions can present operational risks, including the adverse effects of airframe and propeller icing on aircraft performance, which can make managing the airplane’s flightpath and airspeed more difficult and can prevent the airplane from maintaining level flight.
As little as 1⁄4-inch of wing leading-edge ice accumulation can increase the stall speed by 25 to 40 knots and cause sudden departure from controlled fight, according to the alert, which adds: Ice accumulation on pitot tubes can cause flight instruments to cease operating and can affect airspeed, altimeter and vertical speed indicators.
The NTSB says: Some pilots have been taught to wait for a prescribed accumulation of leading-edge ice before activating deice boots to alleviate ice accumulation on flight control surfaces because of the believed threat of ice bridging. However, performance degradation could develop if the deice boots are not activated as soon as icing is encountered.
The notice also warns that many pneumatic deice boot systems have no provision for continuous operation and require pilots to manually cycle the systems. Continuous use of the autopilot in icing conditions can deprive the pilot of the opportunity to detect the buildup of ice on the airframe through changes in longitudinal trim requirements and control forces.
18 • KING AIR MAGAZINE
OCTOBER 2024