Narrative:

I was giving training at the sectors this occurred at. Both aircraft came from sector 22 which is southwest of the sector we were working and were going to 2w6. Sector 22 called over and said that aircraft X was going to cancel IFR and wanted to join up in a formation flight with aircraft Y. We know that you could not do this with general aviation aircraft. We took radar on both aircraft; aircraft Y was at 17;000 feet in front of aircraft X who was assigned 14;000 feet but was climbing through his altitude. Aircraft X went up to 145 and 147 and then finally back down to 14;000 feet. My trainee verified with pilot to make sure he was level at 14;000 feet and aircraft X finally was level. Then the aircraft wanted higher because he couldn't hold altitude due to the weather and turbulence. So we climbed aircraft X to 16;000 feet and everything was ok for a couple minutes. Both aircraft Y and aircraft X were going to the same airport. Aircraft X was a little faster than aircraft Y; but aircraft Y was at 17;000 feet and aircraft X was at 16;000 feet. Then aircraft X jumped up a couple hundred feet again which caused us to lose separation with aircraft Y! Aircraft X came back and said his instruments were giving him conflicted reading and he had vertigo! Once we saw aircraft X could not hold altitude we turned aircraft Y 30 degrees to the left to keep the aircraft apart and separated. We did end up declaring an emergency for aircraft X and tried to ask him to land at nearest airport. The pilot wanted to stay at 16;000 feet because it was clear and he could see. Both aircraft ended up landing at their original airport. We coordinated everything with the proper sectors and approach facilities. The pilot seemed very nervous and somewhat confused but once he got his bearings back he was a lot better. He did not want to change altitude or a land at a closer airport. In the end it all ended up working out; but in my opinion aircraft X got instrument icing from the pitot tubes in front of the aircraft which gave him all the false readings on his instruments. Elms or actual class on what pilots experience with instrument icing and vertigo.

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Original NASA ASRS Text

Title: ZDC Instructor and Developmental report of a situation where two aircraft wanted to become a flight. The controllers did not allow this and one of the aircraft cannot keep altitude and continually climbs and descends. Controllers find out pilot is having icing and vertigo problems and then separate the aircraft even more. A loss of separation occurs when the pilot initially climbs out of assigned altitude.

Narrative: I was giving training at the sectors this occurred at. Both Aircraft came from sector 22 which is SW of the sector we were working and were going to 2W6. Sector 22 called over and said that Aircraft X was going to cancel IFR and wanted to join up in a formation flight with Aircraft Y. We know that you could not do this with general aviation aircraft. We took radar on both aircraft; Aircraft Y was at 17;000 feet in front of Aircraft X who was assigned 14;000 feet but was climbing through his altitude. Aircraft X went up to 145 and 147 and then finally back down to 14;000 feet. My trainee verified with pilot to make sure he was level at 14;000 feet and Aircraft X finally was level. Then the aircraft wanted higher because he couldn't hold altitude due to the weather and turbulence. So we climbed Aircraft X to 16;000 feet and everything was ok for a couple minutes. Both Aircraft Y and Aircraft X were going to the same airport. Aircraft X was a little faster than Aircraft Y; but Aircraft Y was at 17;000 feet and Aircraft X was at 16;000 feet. Then Aircraft X jumped up a couple hundred feet again which caused us to lose separation with Aircraft Y! Aircraft X came back and said his instruments were giving him conflicted reading and he had vertigo! Once we saw Aircraft X could not hold altitude we turned Aircraft Y 30 degrees to the left to keep the aircraft apart and separated. We did end up declaring an emergency for Aircraft X and tried to ask him to land at nearest airport. The pilot wanted to stay at 16;000 feet because it was clear and he could see. Both aircraft ended up landing at their original airport. We coordinated everything with the proper sectors and approach facilities. The pilot seemed very nervous and somewhat confused but once he got his bearings back he was a lot better. He did not want to change altitude or a land at a closer airport. In the end it all ended up working out; but in my opinion Aircraft X got instrument icing from the pitot tubes in front of the aircraft which gave him all the false readings on his instruments. ELMS or actual class on what pilots experience with instrument icing and vertigo.

Data retrieved from NASA's ASRS site 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.