Checklist: Flying In Icing Conditions
Icing can accumulate on an aircraft quickly and can have a devastating effect when it does. Weather-related accidents have been on the decline, although there is still an average of two weather-related fatal accidents per month, says Richard McSpadden, senior vice president of Aircraft Owners and Pilots Association Air Safety Institute. McSpadden presented his tips at Sun 'n Fun 2021 in April.
Of those, the largest percentage is from VFR flights into weather conditions requiring pilots to fly under instrument flight rules rather than visual flight rules, he says.
McSpadden offers a number of tips and warnings when flying in icing conditions:
* Obtain the most updated weather briefing. Hours-old information can be dangerous.
* Icing is most prevalent in temperatures ranging from +35F to -04F. When weather conditions worsen, he advises pilots to have a “bail-out direction” – a direction to fly where the weather is better or improving.
* The tops of cumulus clouds often have more water, which means more rapid icing. Exit them horizontally.
* Icing in stratus clouds is usually 3,000 ft. thick. Climb or descend to exit.
* To navigate a front, penetrate the boundary quickly.
* An aircraft’s tail ices more quickly than the wings. If you haven’t seen ice on your wings, but your aircraft is behaving funny, there could be ice on the tail. Avoid using flaps to avoid tail stalls, fly higher approach speeds and be aware of buffeting.
* When encountering icing conditions, convey to ATC what is going on. Be assertive. Tell ATC that you need to get out of the icing conditions, need to fly as low as possible and need to fly direct to the airport. Declare an emergency if needed.
Watch Changes In Aircraft Performance
* Icing can increase stall speed.
* It can lead to ineffective control, loss of lift and increased drag, even with a thin layer of frost.
* It can block pitot-static systems, in which the airspeed acts like an altimeter and the attitude indicator freezes, giving a false sense of “on-attitude.”
* It can block or reduce forward visibility.
Stay On Guard
* Guard against a “plan continuation bias.” Once a decision is made, the tendency is to continue on the plan when it may be best to change course.
* Guard against overestimating your knowledge, skill and experience.
* Avoid complacency and a “been there, done that, got away with it” attitude.
* Think, decide and plan like a scientist. Consider your planned flight as a hypothesis and be willing to accept new, better or disproving data.