Narrative:

Aircraft X departed tncm and was looking for higher altitude. I climbed him to FL320. Ask him to say the socco estimate; mach number and altitude request. He requested FL370 M.75 and gave an estimate of socco at XA28Z. My d-side told me that FL370 was not available and to stop him at FL340. I did and the pilot stated that he was a medical flight and that at FL340 he would not reach his destination. D-side informed me that next available was FL390. I asked if he was able and he said yes. I climbed him and told him to give me a good rate of climb for traffic cause he was climbing good and continued working the outbound push out of sju; stt; tncm and coy. Sector 6 was very busy but it was do able; when I continued my scan I saw aircraft X slowing his rate of climb. I did my calculations and knew it was going to be a factor with aircraft Y. I called him and assign a 360 heading with no reply from him. Told him to expedite; no reply. At this time he was floating FL361; next hit; FL362. My scope was filled with targets and he wasn't responding. When he finally responded was questioning if the heading assignment was for him. Sector 6 was getting busier by the minute and this guy wasn't responding. He was already in ZNY's airspace when I saw him turn leaving 366. I called the aircraft Y to verify his position; no luck. Told the d-side to contact commercial radio to put him on our frequency. Nothing. I continued working and never got a read back that the aircraft was leveled at FL390. I transmitted on the blind; no answer. I continued to call aircraft Y with no luck. He finally came on frequency 80 miles after. I radar identified him and kept working when he asked if he had traffic approaching socco. I explained to him that I had lost communications with him and that's when he told me that he had responded to a RA (resolution advisory). I never saw how close they got since it happened on non-radar. Our frequencies over the ocean are bad. We transmit constantly with no answer. Transmitters and receivers are constantly malfunctioning and is a daily headache. This situation could have been avoided with good frequencies.

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Original NASA ASRS Text

Title: ZSU Controllers report of a loss of separation over the ocean due to poor radio coverage and an aircraft not climbing with a good rate for traffic.

Narrative: Aircraft X Departed TNCM and was looking for higher altitude. I climbed him to FL320. Ask him to say the SOCCO estimate; Mach number and altitude request. He requested FL370 M.75 and gave an estimate of SOCCO at XA28Z. My D-Side told me that FL370 was not available and to stop him at FL340. I did and the pilot stated that he was a medical flight and that at FL340 he would not reach his destination. D-side informed me that next available was FL390. I asked if he was able and he said yes. I climbed him and told him to give me a good rate of climb for traffic cause he was climbing good and continued working the outbound push out of SJU; STT; TNCM and COY. Sector 6 was very busy but it was do able; when I continued my scan I saw Aircraft X slowing his rate of climb. I did my calculations and knew it was going to be a factor with Aircraft Y. I called him and assign a 360 heading with no reply from him. Told him to expedite; no reply. At this time he was floating FL361; next hit; FL362. My scope was filled with targets and he wasn't responding. When he finally responded was questioning if the heading assignment was for him. Sector 6 was getting busier by the minute and this guy wasn't responding. He was already in ZNY's airspace when I saw him turn leaving 366. I called the Aircraft Y to verify his position; no luck. Told the D-side to contact commercial radio to put him on our frequency. Nothing. I continued working and never got a read back that the aircraft was leveled at FL390. I transmitted on the blind; no answer. I continued to call Aircraft Y with no luck. He finally came on frequency 80 miles after. I radar identified him and kept working when he asked if he had traffic approaching SOCCO. I explained to him that I had lost communications with him and that's when he told me that he had responded to a RA (resolution advisory). I never saw how close they got since it happened on non-radar. Our frequencies over the ocean are bad. We transmit constantly with no answer. Transmitters and receivers are constantly malfunctioning and is a daily headache. This situation could have been avoided with good frequencies.

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.