Date: 201511
Local time of day: 0601-1200
Location: ZDV.ARTCC, CO
Flight conditions: Mixed
Weather elements / visibility: Rain; Snow; Turbulence; Windshear; Icing; 1
Light: Daylight
Aircraft: Small Aircraft; High Wing; 1 Eng; Fixed Gear
Operator: FBO
Operating under: Part 91
Flight plan: VFR
Mission: Training
Flight phase: Cruise
Airspace: Class E ZDV
ATC / advisory: Center ZDV
Reporter organization: FBO
Reporter function: Instructor; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Flight Instructor; Flight Crew Commercial
Human factors: Situational Awareness
Anomaly: Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Contributing factors: Human Factors; Weather
Primary problem: Weather

Narrative: After getting a weather briefing the night before and the morning of the flight. The ceilings were forecasted from 1400-3800 feet AGL. We departed ZZZ1 to fly about 25 miles toward where the weather was; just to see if there was any way around or under the weather. Icing was forecasted at 11;000 feet MSL. We saw what looked like a way around the weather and got around it and then started to fly further north to see if we could continue. We soon realized that the weather was getting worse quickly. We started to turn around and the weather had dropped too low to continue back to our departure point. We then saw clear skies above and proceeded to climb to 12;500 feet. We were able to get above about 80% of most of the weather. We continued north over a broken layer of clouds. About 30 mins into the flight the clouds below started to close in and rise up. At this point we contacted ATC and asked for an IFR clearance to [destination] airport. Once we entered the clouds after getting our clearance; we started to ice up and it was freaking out my student. So I [advised] ATC and started a 180 turn to get back to the better weather behind us. We got back to where the sky was clear above and informed ATC that we were going to circle to try to shed about 1/4 inch of mixed/rime ice that was on the aircraft. ATC then asked us to climb to 14;000 feet. We tried and could only get the aircraft to about 13;650 feet and then called ATC and informed them that was all we had. ATC then had us turn more south to stay out of high terrain. About this time our first bottle of oxygen ran out and we had to buddy breath on our second bottle of oxygen. At this point we had to try for [the destination airport] and re-enter the icing conditions. With outstanding help from ATC we worked to aircraft down slowly as it built up more ice. I was able to keep the aircraft about 300-500 feet above most of the lower altitudes that ATC informed us of. We finally broke out about 20 miles from [the destination airport] and landed safely.




Synopsis: A general aviation flight instructor and student departed in marginal weather in an attempt to fly around or under the weather. When this did not work out; the instructor obtained an IFR clearance and entered instrument conditions; but then began to pick up ice. After turning around and shedding the ice; ATC assisted with continued flight with intermittent icing conditions until locating VFR conditions.