Skyhawk 172/Cutlass 172
Flight Crew Private; Flight Crew Instrument
Flight Crew Last 90 Days 37; Flight Crew Total 1008; Flight Crew Type 650
Human-Machine Interface; Confusion; Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Aircraft Equipment Problem Dissipated; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Clearance; Flight Crew Overcame Equipment Problem; Flight Crew Became Reoriented
Aircraft; Human Factors; Weather
Initially; cruised at 7;000 ft.  From ZZZ to about the ZZZZZ intersection on V185; I was between layers.  ATC requested that I change altitude to an even thousand because I was now westward bound and gave me a choice of up or down.  Up would have put me in the clouds.  So; I requested down to 4;000 ft. because I knew that should be below the freezing level and below the ceiling as I progressed.  Upon reaching 6;000 ft.; I requested to stay at that altitude because I was still between layers and 4;000 ft. would have put me in the clouds for some time before reaching the higher ceilings.  Eventually; the layers merged and I was in the clouds at 6;000 ft.  A short time later; rime ice began to form.  In about a minute; I lost my airspeed indicator.  Just prior to a red X appearing over the G5's airspeed partition; the G5's airspeed tape quickly unwound and a stall indication began flashing.  Also; the GFC 500 autopilot had disengaged.  I told ATC I was in icing and received clearance to descend.The stall indication did not make sense.  But; I was confused by what was happening and pushed forward on the yoke so as to not take any chances. A recovery from a rapid descent and 180 degree turn was executed as I realized a stall was not happening and the auto pilot had disengaged.  ATC offered a 2;000 ft. altitude to get out of the clouds and in warmer temperatures.  I had turned on the pitot heat and the airspeed was functioning on both the airspeed steam gauge and the G5.  The plane was iced but flying without difficulty and the ice was melting rapidly. I turned back on course and continued without further incident below the clouds.  In retrospect; I should have descended to 4;000 ft. instead of stopping at 6;000 ft.  This would have put me in the clouds for awhile; but beneath the freezing level.
Pilot flying C-172 aircraft reported inflight icing.