Icing

[donv]

From NASA Callback:

Icy Aerobatics

While on vectors, this Aero Commander 500 became a live classroom when the pilot encountered icing conditions and experienced its effects first hand.

■ I was in cruise flight at 3,000 feet…following a radar vector…to the ILS. There was moderate to heavy rime icing. I had a high power setting, but my airspeed kept bleeding off until it got down to 120 knots. Turning became very sloppy, and it started to seem like I was in an uncommanded turn. It felt like there was no rudder response. I called…Approach and asked them if their radar showed that I was making a turn. Before they responded, the instruments showed the turn accelerating, and I realized…the symptoms of a stall spin scenario. I pushed in on the yoke and pressed opposite rudder to recover from the stall and climb back up to 3,000 feet. I lost about 700 feet of altitude before I recovered.

I was using [deicing] fluid to get rid of the ice, but I had to ration my fluid because I used it heavily on the initial trip [earlier] that night. There was freezing rain from 4,000 to 6,000 feet on that leg. I departed with 12 gallons of…[deicing] fluid out of the 20 gallon limit.… On this night I chose to go with the minimum quantity for dispatch into known icing conditions.

I learned a few good lessons from this flight.… For future flights, I plan to fly at higher altitudes above the cloud ceiling. Altitude gives you more options and time.… I had time to observe the slow decrease in my airspeed, and I should have requested the quickest approach since the winds were under 10 knots. The next time,… I am going to add…fluid.… It is better to be fully prepared for any scenario.… In the future, [I will] always trust my instruments and…[advise ATC] right away.