My brother and I went flying during Christmas holidays in 20 degree weather. In 4 days we had 4 servo failures on 3 airplanes. First was an elevator servo that stalled in the down position resulting in a total destruction of the plane. The servo was a new tower hobbies and had 6 flights on the plane before the crash. It was 21 degrees out. The 2 nd failure was a futaba aileron servo that was about 4 years old. The servo just started chattering and would not quit. Luckily the P51 did not crash. It was 24 degrees out. The 3 rd failure was in a new P51 sportster on the throttle. It was a hobbyking servo and after the 3 flight on the plane, I landed and was bringing the plane back to me when the servo went from a little above to wide open throttle and stalled. Luckily I nosed the plane over and killed the engine before it ran over me, his plane and his truck. It was 18 degrees. The 4 th failure was the other aileron servo on the P51. It got sluggish and really slow. It was a futaba servo about 4 years old. Were we flying in weather that was just too cold for the electronics or just a fluke we had 2 new and 2 older servos all fail? We have both been flying over 25 years and never had so many failures on servos.