Narrative:

I was working sector 11;12;77 combined r-side. There was training on the RA position. Aircraft X departed VFR off of ZZZ airport. I gave aircraft X a code and ZZZ altimeter; maintain VFR. I asked aircraft X his altitude & position; saw his code where he reported; identified and cleared to ZZZ1 airport as filed; climb and maintain 170. Aircraft X advised he had a pressurization problem and said 'stand by one we have a problem here.' I cleared aircraft X to maintain 160. I said; 'do you require any assistance at this time?' I heard aircraft X say return to ZZZ. I cleared him back to the ZZZ airport. Aircraft X said ZZZ1. I questioned; 'which one do you want?' aircraft X said ZZZ1. I asked aircraft X; 'are you requesting direct ZZZ1?' aircraft X said 'stand by.' ( I knew the pilot was busy ) I waited a couple of minutes and asked aircraft X; 'when you get a chance...' aircraft X responded 'stand by one'. Aircraft X advised he had a pressurization problem and wanted to return to ZZZ airport. I cleared him to the; 'ZZZ airport via left or right; make it right turn maintain 16 thousand.' he read it back but the direction of turn was not heard clearly. (This is in an area of limited radar coverage and radios get hard to hear.) I lost the aircraft in radar and told aircraft X radar contact lost; and mileage from ZZZ airport. Aircraft X declared and emergency! Aircraft X had turned left; showed up in radar in a 16;400 ft. Mia at 16;000 ft. Approximately five miles in the corner of the MEA; heading out of the MEA heading towards ZZZ airport. I gave him radar contact. He asked for lower; I told him he could expect lower in two minutes. I advised aircraft X of the airport position and asked if he had the airport in sight. He responded airport in sight. I cleared aircraft X for visual approach to the ZZZ airport. I verified he had the weather and NOTAMS for ZZZ; then changed him to advisory frequency. Aircraft X then canceled IFR. Recommendation: at the time we all thought we heard the pilot say right turn; listened to the tape and it's very hard to hear what he said; could have been right or left. So I'd say if any question issue the direction of turn...again.

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Original NASA ASRS Text

Title: Enroute controller described an emergency event when an aircraft's turn instructions may have been missed and the aircraft entered an MIA lower than required.

Narrative: I was working sector 11;12;77 combined R-side. There was training on the RA position. Aircraft X departed VFR off of ZZZ airport. I gave Aircraft X a code and ZZZ altimeter; maintain VFR. I asked Aircraft X his altitude & position; saw his code where he reported; identified and cleared to ZZZ1 airport as filed; climb and maintain 170. Aircraft X advised he had a pressurization problem and said 'stand by one we have a problem here.' I cleared Aircraft X to maintain 160. I said; 'do you require any assistance at this time?' I heard Aircraft X say return to ZZZ. I cleared him back to the ZZZ airport. Aircraft X said ZZZ1. I questioned; 'which one do you want?' Aircraft X said ZZZ1. I asked Aircraft X; 'are you requesting direct ZZZ1?' Aircraft X said 'stand by.' ( I knew the pilot was busy ) I waited a couple of minutes and asked Aircraft X; 'when you get a chance...' Aircraft X responded 'stand by one'. Aircraft X advised he had a pressurization problem and wanted to return to ZZZ airport. I cleared him to the; 'ZZZ airport via left or right; make it right turn maintain 16 thousand.' He read it back but the direction of turn was not heard clearly. (This is in an area of limited radar coverage and radios get hard to hear.) I lost the aircraft in RADAR and told Aircraft X RADAR contact lost; and mileage from ZZZ airport. Aircraft X declared and Emergency! Aircraft X had turned left; showed up in RADAR in a 16;400 ft. MIA at 16;000 ft. approximately five miles in the corner of the MEA; heading out of the MEA heading towards ZZZ airport. I gave him RADAR contact. He asked for lower; I told him he could expect lower in two minutes. I advised Aircraft X of the airport position and asked if he had the airport in sight. He responded airport in sight. I cleared Aircraft X for visual approach to the ZZZ airport. I verified he had the weather and NOTAMS for ZZZ; then changed him to advisory frequency. Aircraft X then canceled IFR. Recommendation: at the time we all thought we heard the pilot say right turn; listened to the tape and it's very hard to hear what he said; could have been right or left. So I'd say if any question issue the direction of turn...again.

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.