Date: 201404
Local time of day: 1201-1800
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Weather elements / visibility: Cloudy; Icing
Light: Daylight
Aircraft: Small Aircraft; High Wing; 1 Eng; Retractable Gear
Operator: Personal
Operating under: Part 91
Flight plan: VFR
Mission: Personal
Flight phase: Cruise
Airspace: Class A ZZZ; Class E ZZZ
ATC / advisory: Center ZZZ
Reporter organization: Personal
Reporter function: Single Pilot; Pilot Flying
Reporter qualification: Flight Crew Instrument
Human factors: Communication Breakdown; Situational Awareness; Workload; Training / Qualification
Anomaly: Airspace Violation All Types; Deviation / Discrepancy - Procedural Clearance; 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; Flight Crew Took Evasive Action
Contributing factors: Procedure; Weather; Airspace Structure
Primary problem: Weather

Narrative: Prior to departure I contacted FSS automated service and received Outlook Briefing and evaluated Duats weather radar and other related data early that morning. Early afternoon I contacted FSS again and received a full Standard Briefing in addition to consulting the Duats data. The briefing at that time related that the weather; icing conditions would clear out of the area by our expected arrival time; and that flight towards the southern part of the state would enable VFR conditions. We departed mid afternoon and flew the route of flight as planned; climbing VFR until reaching cruise altitude at 17;500. Cloud density increased with us flying on top. The cloud tops appeared to be reasonably level with clear conditions above and were layered and varied from approximately 15;000 up requiring deviation from course to remain VFR. Mid flight; I estimated the cloud elevation to enable VFR all the way until our destination.At cruise to the west; the cloud tops were higher than estimated. Restricted flight areas to the north and south of our course intimidated me from deviating from course. The aircraft is equipped with prop de-ice and pitot heat; but is not equipped for flight into known icing conditions. When it became apparent that I needed to deviate from the VFR altitude to remain clear of clouds and safe from potential icing conditions; I began a climb which required a deviation into Class A airspace and simultaneously established Freq for ATC. I contacted ARTCC and was instructed to Standby. During the standby; I was required to climb to approximately 19;300 to remain clear of clouds. Upon ATC re-establishing contact; I informed them of altitude; conditions and requested clearance. ATC was helpful in providing vectors; and on the IMC descent we encountered moderate icing conditions build up in a short time; until breaking clear of clouds to establish visual approach to the airport. After the event and upon reflection; I should have established 7700 on the transponder and established contact with ATC prior to entering the Class A space. At the time the load of flying the airplane with control; clear of icing conditions; near restricted airspace with mountain terrain and two passengers prevented me from taking that clear action. Alternatively I could have turned the plane around and returned to my departure airport.




Synopsis: A Pilot departed a mountainous area VFR in VMC and climbed to 17;500 feet. He climbed to 19;500 feet before contacting ATC for clearance because the cloud tops rose.