Air Safety Institute Safety Spotlight
Cold RealityWinter can be a challenging season for flying. Even in the southern states, pilots can encounter ice in flight. Ice destroys the smooth flow of air over a wing, increasing drag while decreasing the ability to create lift. The airplane may stall at a much higher speed and lower angle of attack than normal. It can roll or pitch uncontrollably, and recovery may be impossible.
Case in point: On January 13, 2006, a Cirrus SR22 had an in-flight loss of control while climbing in icing conditions near Childersburg, Alabama. The pilot and two passengers survived the ordeal because, as they say, "chute happens."
The IFR flight departed Birmingham International Airport en route to Orlando at 3:44 p.m. Instructed to climb to 7,000 feet, the pilot entered the clouds at 5,000 feet, climbing at 120 knots. Upon reaching 7,000 feet, the airplane encountered icing conditions. The pilot received approval to climb to 9,000 feet. However, as the airplane emerged from the cloud tops at 8,000 feet, it began to buffet. The airspeed indicator read 80 knots. The airplane stalled and began spinning to the left.
The pilot reduced power, neutralized the flight controls, and applied right rudder. Unable to break the spin, he deployed the aircraft's ballistic parachute system. The airplane descended under the parachute canopy, struck trees, and came to rest about four feet above the ground. The aircraft received substantial damage, but the pilot and two passengers reported no injuries.
On the night before the accident, the 12,700-hour, ATP-certificated pilot obtained a full DUAT briefing. The briefing was not valid for the time of the accident. Before noon the next day, the pilot requested an abbreviated DUAT weather briefing for his route. The in-flight advisories were to expire at 3 p.m.--nearly an hour before his departure time.
The pilot stated he was not aware of Airmet Zulu update 3, which was issued an hour before he departed Birmingham and was broadcast over the XM Satellite Weather service available in the airplane. It warned of occasional moderate mixed icing in clouds between 3,000 and 8,000 feet.
The NTSB determined the probable cause of the accident was the pilot's inadequate preflight planning, failure to obtain a current weather briefing, and his decision to operate the airplane in a known area of icing outside the aircraft's certification standards.
Because most light aircraft are not approved for flight in known icing conditions, it is critical for pilots to consult the most recent weather information--especially when planning a flight through a cloud layer in winter months. It's also wise to avoid using the autopilot in potential icing conditions. An autopilot can mask the aerodynamic effects of ice and may fly the aircraft into a stall. Finally, remember to request pireps--and give some of your own--along your route if you suspect icing to be a potential problem.
For more information, take the AOPA Air Safety Foundation's new online course Weather Wise: Precipitation and Icing.
An aviation technical writer with the AOPA Air Safety Foundation, Carl Peterson creates interactive courses and other safety education materials for the aviation community. He has been flying since 1989.
By Carl Peterson