Narrative:

On may/xx/93, I was working at ZHU center on the oceanic and offshore sectors combined. Oceanic provides separation services within the houston cta/fir. Offshore sector was created to provide separation for helicopter operations between the mainland and the numerous oil rigs located off the texas and louisiana coasts. The offshore sector is a completely non radar environment. Atx X departed an oil rig located at 2815N/9144W (EI314) en route to the LLA153/25 fix via the LLA153/80 fix, thence the LLA153R. At XA13 UTC, reported the LLA153/80, level at 3000 ft, and estimating the 25 mi fix at XA34 UTC called for clearance from the SM265 block to intercoastal city. The pilot explained that he was inbound to the rig and was about to land, and would be departing about XA30. He was requesting his clearance now because he would lose communications while on the platform. I issued a clearance to the LLA153/25 via the LLA153/30, thence the LLA153R, maintain 3000 ft, and issued a clearance void time of XA35 UTC. The pilot acknowledged and advised he would call on departure. At XA29 UTC, lafayette approach control (lft approach) called and asked the location of atx X. I advised him atx X was estimating the 25 mi fix at XA34 UTC, level at 3000 ft. Lft approach requested that he be descended to 2000 ft. I issued the clearance within the same min. At XA31:54 UTC, atx X reported the 30 mi fix, level at 2000 ft. I switched him to lft approach frequency. At XA32:31 UTC, atx Y reported his departure from SM265 as XA31 UTC, climbing to 3000 ft. At XA33:03 UTC, atx X reported the 27 mi fix, level at 2000 ft. I reissued the frequency change to lft approach. At XA34:58 UTC, atx Y reported level at 3000 ft, estimating the LLA153/30 at XA39 UTC, and the LLA153/25 at XA42 UTC. I acknowledged and requested him to report the 35 mi fix. He replied that he was direct to the 30 mi fix, so I instructed him to report passing 35 mi from lla. Atx Y said that he was already inside 35 mi from lla, which I asked him to verify, which he did. I then asked him to verify his departure block as SM265, and then his departure coordinates. He replied he departed 2911N/9157W. Since he had already reported level at 3000 ft, he was separated from atx Y. I immediately called lft approach, advised that atx Y was inbound at 3000 ft estimating the LLA153/30 at XA39 UTC, and said that I had received the wrong departure coordinates on the flight plan. Lft approach was able to approve the altitude, and I switched atx Y to them at XA37 UTC. Atx Y had airfiled his return flight plan with deridder AFSS (dri AFSS). They erroneously input 2811N/9157W as his departure point, which is 60 mi south of his actual departure rig. I issued that departure clearance thinking that was where atx Y would be on departure. As it turns out, atx Y departed only about 10 mi from the en route atx X. The atx Y pilot heard the atx X pilot report the 27 mi fix at 2000 ft, and leveled at 1500 ft. I can only surmise that atx Y figured that he was clear of the traffic, and so continued his climb to 3000 ft. (Atx Y never advised me that he leveled off at 1500 ft). Had the correct latitude/longitude of atx Y been in the center's flight plan, I would have never issued that departure clearance. I have recently been informed that our center's computer utilizes only about 10 percent of its available memory capacity. To avoid these type of problems in the future, I think we should adapt the latitude/longitude of the center of each individual offshore block and label them as airports (such as SM265, VM56, EI314, etc). Therefore, helicopter operators and pilots would be able to file departure blocks instead of departure coordinates, thereby reducing the chance for an error.

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Original NASA ASRS Text

Title: FSS CTLR ENTERED WRONG LATITUDE LONGITUDE COORDINATES. ATX Y HAD LESS THAN STANDARD NONRADAR SEPARATION FROM ATX X. SYS ERROR.

Narrative: ON MAY/XX/93, I WAS WORKING AT ZHU CTR ON THE OCEANIC AND OFFSHORE SECTORS COMBINED. OCEANIC PROVIDES SEPARATION SVCS WITHIN THE HOUSTON CTA/FIR. OFFSHORE SECTOR WAS CREATED TO PROVIDE SEPARATION FOR HELI OPS BTWN THE MAINLAND AND THE NUMEROUS OIL RIGS LOCATED OFF THE TEXAS AND LOUISIANA COASTS. THE OFFSHORE SECTOR IS A COMPLETELY NON RADAR ENVIRONMENT. ATX X DEPARTED AN OIL RIG LOCATED AT 2815N/9144W (EI314) ENRTE TO THE LLA153/25 FIX VIA THE LLA153/80 FIX, THENCE THE LLA153R. AT XA13 UTC, RPTED THE LLA153/80, LEVEL AT 3000 FT, AND ESTIMATING THE 25 MI FIX AT XA34 UTC CALLED FOR CLRNC FROM THE SM265 BLOCK TO INTERCOASTAL CITY. THE PLT EXPLAINED THAT HE WAS INBOUND TO THE RIG AND WAS ABOUT TO LAND, AND WOULD BE DEPARTING ABOUT XA30. HE WAS REQUESTING HIS CLRNC NOW BECAUSE HE WOULD LOSE COMS WHILE ON THE PLATFORM. I ISSUED A CLRNC TO THE LLA153/25 VIA THE LLA153/30, THENCE THE LLA153R, MAINTAIN 3000 FT, AND ISSUED A CLRNC VOID TIME OF XA35 UTC. THE PLT ACKNOWLEDGED AND ADVISED HE WOULD CALL ON DEP. AT XA29 UTC, LAFAYETTE APCH CTL (LFT APCH) CALLED AND ASKED THE LOCATION OF ATX X. I ADVISED HIM ATX X WAS ESTIMATING THE 25 MI FIX AT XA34 UTC, LEVEL AT 3000 FT. LFT APCH REQUESTED THAT HE BE DSNDED TO 2000 FT. I ISSUED THE CLRNC WITHIN THE SAME MIN. AT XA31:54 UTC, ATX X RPTED THE 30 MI FIX, LEVEL AT 2000 FT. I SWITCHED HIM TO LFT APCH FREQ. AT XA32:31 UTC, ATX Y RPTED HIS DEP FROM SM265 AS XA31 UTC, CLBING TO 3000 FT. AT XA33:03 UTC, ATX X RPTED THE 27 MI FIX, LEVEL AT 2000 FT. I REISSUED THE FREQ CHANGE TO LFT APCH. AT XA34:58 UTC, ATX Y RPTED LEVEL AT 3000 FT, ESTIMATING THE LLA153/30 AT XA39 UTC, AND THE LLA153/25 AT XA42 UTC. I ACKNOWLEDGED AND REQUESTED HIM TO RPT THE 35 MI FIX. HE REPLIED THAT HE WAS DIRECT TO THE 30 MI FIX, SO I INSTRUCTED HIM TO RPT PASSING 35 MI FROM LLA. ATX Y SAID THAT HE WAS ALREADY INSIDE 35 MI FROM LLA, WHICH I ASKED HIM TO VERIFY, WHICH HE DID. I THEN ASKED HIM TO VERIFY HIS DEP BLOCK AS SM265, AND THEN HIS DEP COORDINATES. HE REPLIED HE DEPARTED 2911N/9157W. SINCE HE HAD ALREADY RPTED LEVEL AT 3000 FT, HE WAS SEPARATED FROM ATX Y. I IMMEDIATELY CALLED LFT APCH, ADVISED THAT ATX Y WAS INBOUND AT 3000 FT ESTIMATING THE LLA153/30 AT XA39 UTC, AND SAID THAT I HAD RECEIVED THE WRONG DEP COORDINATES ON THE FLT PLAN. LFT APCH WAS ABLE TO APPROVE THE ALT, AND I SWITCHED ATX Y TO THEM AT XA37 UTC. ATX Y HAD AIRFILED HIS RETURN FLT PLAN WITH DERIDDER AFSS (DRI AFSS). THEY ERRONEOUSLY INPUT 2811N/9157W AS HIS DEP POINT, WHICH IS 60 MI S OF HIS ACTUAL DEP RIG. I ISSUED THAT DEP CLRNC THINKING THAT WAS WHERE ATX Y WOULD BE ON DEP. AS IT TURNS OUT, ATX Y DEPARTED ONLY ABOUT 10 MI FROM THE ENRTE ATX X. THE ATX Y PLT HEARD THE ATX X PLT RPT THE 27 MI FIX AT 2000 FT, AND LEVELED AT 1500 FT. I CAN ONLY SURMISE THAT ATX Y FIGURED THAT HE WAS CLR OF THE TFC, AND SO CONTINUED HIS CLB TO 3000 FT. (ATX Y NEVER ADVISED ME THAT HE LEVELED OFF AT 1500 FT). HAD THE CORRECT LATITUDE/LONGITUDE OF ATX Y BEEN IN THE CTR'S FLT PLAN, I WOULD HAVE NEVER ISSUED THAT DEP CLRNC. I HAVE RECENTLY BEEN INFORMED THAT OUR CTR'S COMPUTER UTILIZES ONLY ABOUT 10 PERCENT OF ITS AVAILABLE MEMORY CAPACITY. TO AVOID THESE TYPE OF PROBS IN THE FUTURE, I THINK WE SHOULD ADAPT THE LATITUDE/LONGITUDE OF THE CTR OF EACH INDIVIDUAL OFFSHORE BLOCK AND LABEL THEM AS ARPTS (SUCH AS SM265, VM56, EI314, ETC). THEREFORE, HELI OPERATORS AND PLTS WOULD BE ABLE TO FILE DEP BLOCKS INSTEAD OF DEP COORDINATES, THEREBY REDUCING THE CHANCE FOR AN ERROR.

Data retrieved from NASA's ASRS site as of July 2007 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.