Date: 201710
Local time of day: 1201-1800
Location: PCT.TRACON, VA
Flight conditions: Mixed
Weather elements / visibility: Icing; 10
Light: Daylight
Aircraft: SR22
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Cruise
Airspace: Class E PCT
ATC / advisory: TRACON PCT
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Commercial; Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Multiengine
Anomaly: ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Procedure; Weather
Primary problem: Weather

Narrative: I was at 10;000 ft MSL on an IFR flight plan. The OAT was approximately -8 Celsius; and I saw a cloud deck in front of me. I believed I would remain visual above the cloud; which was mandatory because my aircraft is not approved for known icing. However; as I was approximately 3 minutes from the cloud; I realized my altitude was on a conflicting course (I'd estimate tops of the stratus layer were 10;700 ft MSL). I immediately told ATC that I have a request. They were extremely busy. I made several more requests accompanied by 'assistance is needed.' At that time I may have been acknowledged and told to stand by. At this point I was one minute from entering the cloud. My further request for immediate altitude change to avoid icing got somewhat confrontational responses from the ATC facility. The replies were 'Negative; traffic above and traffic below'. Several times I thought the altitude approval was forthcoming; instead they gave me a frequency switch. I made several strong statements; 'Climbing to 12;000 ft now to avoid ice. Aircraft not approved for icing.' Unfortunately I was trying to bluff ATC believing I would get the climb approval. At this point I decided not to do a 180 degree turn and not to climb due to busy airspace traffic and pressure from ATC. I did not declare but thought I would momentarily skim the top of the cloud and that would be the safest course of action; all other factors considered. I turned on the aircraft's anti-icing and briefly tried to cheat up a few hundred feet to the top of the cloud without causing any conflict with other potential aircraft. As I did I finally got my climb clearance to 12;000 ft. My aircraft picked up moderate rime icing on the leading edges. Anticipating topping the layer or getting altitude deviation approval from ATC caused me to activate the system rather late; which may have led to increased ice accretion. Recognizing the PIC has final authority; I reflect perhaps I should have declared and deviated from ATC instructions. ATC's failure to acknowledge my serious situation was a strong contributor to the problem.




Synopsis: SR22 Pilot initiated a climb prior to receiving ATC approval in an attempt to avoid icing conditions.