Narrative:

I was on an IFR flight plan. Up until the time of the event we had been in and out of the clouds picking up light rime icing. The autopilot was engaged. Occasional use of the aircraft's ice protection system (tks) was easily keeping the wings; prop; and windshield clear of ice buildups. Our initial cleared altitude was 9000 ft. Approximately 20 minutes into the flight I realized we would be right at the tops of the clouds at 9000 ft MSL and requested to climb to 10;000 ft MSL. Approach control cleared us to 10;000 ft MSL and handed us off to center. We were initially above the clouds at 10;000 ft; but soon realized we would again be in the clouds. Center gave us a climb to 11;000 ft MSL where we remained in IMC. The controller reported another aircraft ahead of us was in VMC at 13;000 ft MSL and offered a climb to 13;000 MSL.as I considered the options of climbing to 13;000 ft (we had supplemental oxygen on board); I first noted significant ice accumulating on the windshield and wings; and then the airspeed began to fluctuate and suddenly dropped to 60 KIAS on the pfd. I immediately recognized a pitot-static system failure; disconnected the autopilot and began hand flying using the attitude indicator and standby instruments as primary references. I also immediately noted that; although the ice-protection switch was on; the pitot heat switch was in the off position. I turned on the pitot heat; selected alternate static air and advised center. The center controller cleared me for a descent to 8000 ft; which I initiated slowly using only the attitude indicator as a reference. Within 2 minutes the airspeed and altimeter began indicating normally. I continued the descent using the attitude indicator and briefly referencing the altimeter. We broke out into VMC at approximately 8000 ft MSL and the controller cleared us to 6000 ft MSL as a final altitude. With all systems now working properly; and visual meteorological condition reported enroute to my destination; I elected to continue to [destination]. The rest of the trip was uneventful and a safe landing was completed.in hindsight I realized that I traditionally do not turn on the pitot heat because most of my personal flying is VFR. Although I consciously turned the ice protection on and off several times; I never noticed that the pitot heat switch; directly next to the ice protection switches; was in the off position. I will now break that habit pattern by always turning on the pitot heat before takeoff; regardless the flight conditions.

Related reports:

Google
 

Original NASA ASRS Text

Title: SR22 pilot reported he noted abnormal airspeed indications while flying in icing conditions and found the pitot heat had not been turned on.

Narrative: I was on an IFR flight plan. Up until the time of the event we had been in and out of the clouds picking up light rime icing. The autopilot was engaged. Occasional use of the aircraft's ice protection system (TKS) was easily keeping the wings; prop; and windshield clear of ice buildups. Our initial cleared altitude was 9000 ft. Approximately 20 minutes into the flight I realized we would be right at the tops of the clouds at 9000 ft MSL and requested to climb to 10;000 ft MSL. Approach Control cleared us to 10;000 ft MSL and handed us off to Center. We were initially above the clouds at 10;000 ft; but soon realized we would again be in the clouds. Center gave us a climb to 11;000 ft MSL where we remained in IMC. The controller reported another aircraft ahead of us was in VMC at 13;000 ft MSL and offered a climb to 13;000 MSL.As I considered the options of climbing to 13;000 ft (we had supplemental oxygen on board); I first noted significant ice accumulating on the windshield and wings; and then the airspeed began to fluctuate and suddenly dropped to 60 KIAS on the PFD. I immediately recognized a pitot-static system failure; disconnected the autopilot and began hand flying using the attitude indicator and standby instruments as primary references. I also immediately noted that; although the ice-protection switch was on; the Pitot Heat switch was in the Off position. I turned on the Pitot Heat; selected Alternate Static Air and advised Center. The Center controller cleared me for a descent to 8000 ft; which I initiated slowly using only the attitude indicator as a reference. Within 2 minutes the airspeed and altimeter began indicating normally. I continued the descent using the attitude indicator and briefly referencing the altimeter. We broke out into VMC at approximately 8000 ft MSL and the controller cleared us to 6000 ft MSL as a final altitude. With all systems now working properly; and visual meteorological condition reported enroute to my destination; I elected to continue to [destination]. The rest of the trip was uneventful and a safe landing was completed.In hindsight I realized that I traditionally do not turn on the pitot heat because most of my personal flying is VFR. Although I consciously turned the ice protection on and off several times; I never noticed that the Pitot Heat switch; directly next to the Ice Protection switches; was in the Off position. I will now break that habit pattern by always turning on the pitot heat before takeoff; regardless the flight conditions.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.