Narrative:

Aircraft was on an IFR flight plan level at 6;000 ft enroute to ZZZ2. I had taken the radar hand off on the aircraft and was talking to him. When he was approximately 10 NM south of my airspace; northbound; reported picking up rime ice requesting lower. I coordinated with the controller of the sector he was in for lower and told him to descend and maintain 5;000 ft and to say flight conditions reaching. Reaching 5;000 ft he said he was picking up severe icing and needed to get lower. I told him to descend and maintain 4;000 ft and asked if he wanted to divert. He said he wanted to and I cleared him to ZZZ airport and put him on a vector to intercept the ILS approach. I also told him that there was a satellite airport (ZZZ1) approximately 5 miles northeast of his position that he could divert to as well if necessary. He said that he wanted to go there and I then cleared him and put him on a vector for the VOR approach. The ZZZ1 localizer approach was out of service. On the 300 assigned heading he appeared to be turning eastbound and I advised him as such and reiterated to fly the 300 heading. He was descending below 4;000 ft and I told him to maintain 3;700 ft (which was my lowest MVA). He descended to 3;400 ft and I told him that his altitude was indicating 3;400 ft and to maintain 3;700 ft. He said he was having difficulty and I asked if he was declaring an emergency. He said no and said that he saw a hole and wanted to descend down through it. I asked if he was declaring an emergency and he said no. Being that he was unable to maintain altitude and fly assigned headings while still on an IFR flight plan I told him I was declaring an emergency for him and altitude was his discretion. I advised the pilot of obstacles nearby and shortly after he said he was in VFR conditions and wanted to cancel his IFR flight plan and continue northwest bound toward his destination of ZZZ2. I asked his flight conditions and requested VFR altitude and he said the bases were around 2;000 ft MSL and that he would proceed northwest bound at approximately 1;500 ft. I advised him of terrain higher than his reported cloud bases and suggested that he land at a nearby satellite airport. He agreed and I suggested a vector to ZZZ1 airport. He said he could not continue eastbound because the clouds were too close to the terrain. I asked him if he saw the river below. He said he did and I told him he should follow that northeast bound and it would lead him to another satellite airport adjacent to the river. I kept pointing out obstacles along his flight path along the river and terminated his radar service approximately 5 miles from the satellite airport (ZZZ3). I monitored his VFR tag until it flew past ZZZ3 northbound approximately 4 miles and called him on the ZZZ3 unicom. I told him to contact approach on my frequency. When he came up on my frequency I told him it appeared he flew past ZZZ3 airport. He replied yes and that he had decided to continue on; northwest bound; along the river to see how far he could get. I asked if he wanted any additional services and he said no. Recommendation; I think a better understanding of the winter weather conditions along the proposed route of flight and deicing equipment would have helped this pilot more. I also think that a willingness to land and wait out the weather rather than pressing on when conditions are poor would have also helped.

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Original NASA ASRS Text

Title: Approach Controller details an account of the attempts to assist an IFR aircraft experiencing icing condition only to discover the aircraft elected to continue VFR to the original destination in questionable weather conditions.

Narrative: Aircraft was on an IFR flight plan level at 6;000 FT enroute to ZZZ2. I had taken the RADAR hand off on the aircraft and was talking to him. When he was approximately 10 NM south of my airspace; northbound; reported picking up rime ice requesting lower. I coordinated with the Controller of the sector he was in for lower and told him to descend and maintain 5;000 FT and to say flight conditions reaching. Reaching 5;000 FT he said he was picking up severe icing and needed to get lower. I told him to descend and maintain 4;000 FT and asked if he wanted to divert. He said he wanted to and I cleared him to ZZZ airport and put him on a vector to intercept the ILS approach. I also told him that there was a satellite airport (ZZZ1) approximately 5 miles northeast of his position that he could divert to as well if necessary. He said that he wanted to go there and I then cleared him and put him on a vector for the VOR approach. The ZZZ1 LOC approach was out of service. On the 300 assigned heading he appeared to be turning eastbound and I advised him as such and reiterated to fly the 300 heading. He was descending below 4;000 FT and I told him to maintain 3;700 FT (which was my lowest MVA). He descended to 3;400 FT and I told him that his altitude was indicating 3;400 FT and to maintain 3;700 FT. He said he was having difficulty and I asked if he was declaring an emergency. He said no and said that he saw a hole and wanted to descend down through it. I asked if he was declaring an emergency and he said no. Being that he was unable to maintain altitude and fly assigned headings while still on an IFR flight plan I told him I was declaring an emergency for him and altitude was his discretion. I advised the pilot of obstacles nearby and shortly after he said he was in VFR conditions and wanted to cancel his IFR flight plan and continue northwest bound toward his destination of ZZZ2. I asked his flight conditions and requested VFR altitude and he said the bases were around 2;000 FT MSL and that he would proceed northwest bound at approximately 1;500 FT. I advised him of terrain higher than his reported cloud bases and suggested that he land at a nearby satellite airport. He agreed and I suggested a vector to ZZZ1 airport. He said he could not continue eastbound because the clouds were too close to the terrain. I asked him if he saw the river below. He said he did and I told him he should follow that northeast bound and it would lead him to another satellite airport adjacent to the river. I kept pointing out obstacles along his flight path along the river and terminated his RADAR service approximately 5 miles from the satellite airport (ZZZ3). I monitored his VFR tag until it flew past ZZZ3 northbound approximately 4 miles and called him on the ZZZ3 UNICOM. I told him to contact Approach on my frequency. When he came up on my frequency I told him it appeared he flew past ZZZ3 airport. He replied yes and that he had decided to continue on; northwest bound; along the river to see how far he could get. I asked if he wanted any additional services and he said no. Recommendation; I think a better understanding of the winter weather conditions along the proposed route of flight and deicing equipment would have helped this pilot more. I also think that a willingness to land and wait out the weather rather than pressing on when conditions are poor would have also helped.

Data retrieved from NASA's ASRS site as of April 2012 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.