Narrative:

2 conflicts occurred en route from galveston (gls) to hooks (dwh). The direct route between dwh and gls runs directly through the TCA, so visual flts have to skirt the TCA either to the west or east. The recent expansion of the TCA forced my route near the 2000 ft towers southwest of houston (near houston southwest airport). The towers were difficult to see in the haze and the 2000 ft floor of the TCA prevents going over them. I elected to make the return flight (gls-dwh) on the east side of the TCA. The first conflict occurred about 6 NM due east of efd. I was northbound at 1700 ft MSL and the traffic (a high wing) was sbound about 100-200 ft below my altitude. I spotted the traffic at only 1 mi (about 1 O'clock low) and we passed with a separation of less than 200 ft vertical and 1000 ft horizontal. No evasive action was necessary nor was there time for it. I proceeded north towards la porte. As I neared the airport, I had difficulty spotting the field. When I found the field I switched to the unicom frequency and announced I was overflying the field at 1700 ft. When I completed the call, I spotted the second conflict at my 9 O'clock low. It was a high wing, also northbound, which I had overtaken. I passed it with less than 200 ft vertical and less than 500 ft horizontal separation. No evasive action was taken since I was past him when spotted. I estimate the speed difference was 20-30 mph. I don't know if the other aircraft made a position call, but he heard mine because he asked if I saw him, which I had by that time. In hindsight, I should have been monitoring the unicom frequencys further out. However, the TCA tends to force traffic into close proximity because of the GA airports with pattern altitude of 1000 ft MSL and the floor of the TCA at 2000 ft MSL, traffic tends to fly between 1200-1800 ft MSL in all directions. I would suggest recommended rtes and altitudes for transiting aircraft, along with a separate common TA frequency with more named reporting points. Also, need to adjust TCA around the 2000 ft towers to allow safe passage over or around in limited visibility.

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Original NASA ASRS Text

Title: POTENTIAL CONFLICT AND NMAC EXPERIENCED BY PVT PLT IN ONE FLT IN PROX OF TCA ATA'S.

Narrative: 2 CONFLICTS OCCURRED ENRTE FROM GALVESTON (GLS) TO HOOKS (DWH). THE DIRECT RTE BTWN DWH AND GLS RUNS DIRECTLY THROUGH THE TCA, SO VISUAL FLTS HAVE TO SKIRT THE TCA EITHER TO THE W OR E. THE RECENT EXPANSION OF THE TCA FORCED MY RTE NEAR THE 2000 FT TOWERS SW OF HOUSTON (NEAR HOUSTON SW ARPT). THE TWRS WERE DIFFICULT TO SEE IN THE HAZE AND THE 2000 FT FLOOR OF THE TCA PREVENTS GOING OVER THEM. I ELECTED TO MAKE THE RETURN FLT (GLS-DWH) ON THE E SIDE OF THE TCA. THE FIRST CONFLICT OCCURRED ABOUT 6 NM DUE E OF EFD. I WAS NBOUND AT 1700 FT MSL AND THE TFC (A HIGH WING) WAS SBOUND ABOUT 100-200 FT BELOW MY ALT. I SPOTTED THE TFC AT ONLY 1 MI (ABOUT 1 O'CLOCK LOW) AND WE PASSED WITH A SEPARATION OF LESS THAN 200 FT VERT AND 1000 FT HORIZ. NO EVASIVE ACTION WAS NECESSARY NOR WAS THERE TIME FOR IT. I PROCEEDED N TOWARDS LA PORTE. AS I NEARED THE ARPT, I HAD DIFFICULTY SPOTTING THE FIELD. WHEN I FOUND THE FIELD I SWITCHED TO THE UNICOM FREQ AND ANNOUNCED I WAS OVERFLYING THE FIELD AT 1700 FT. WHEN I COMPLETED THE CALL, I SPOTTED THE SECOND CONFLICT AT MY 9 O'CLOCK LOW. IT WAS A HIGH WING, ALSO NBOUND, WHICH I HAD OVERTAKEN. I PASSED IT WITH LESS THAN 200 FT VERT AND LESS THAN 500 FT HORIZ SEPARATION. NO EVASIVE ACTION WAS TAKEN SINCE I WAS PAST HIM WHEN SPOTTED. I ESTIMATE THE SPD DIFFERENCE WAS 20-30 MPH. I DON'T KNOW IF THE OTHER ACFT MADE A POS CALL, BUT HE HEARD MINE BECAUSE HE ASKED IF I SAW HIM, WHICH I HAD BY THAT TIME. IN HINDSIGHT, I SHOULD HAVE BEEN MONITORING THE UNICOM FREQS FURTHER OUT. HOWEVER, THE TCA TENDS TO FORCE TFC INTO CLOSE PROX BECAUSE OF THE GA ARPTS WITH PATTERN ALT OF 1000 FT MSL AND THE FLOOR OF THE TCA AT 2000 FT MSL, TFC TENDS TO FLY BTWN 1200-1800 FT MSL IN ALL DIRECTIONS. I WOULD SUGGEST RECOMMENDED RTES AND ALTS FOR TRANSITING ACFT, ALONG WITH A SEPARATE COMMON TA FREQ WITH MORE NAMED RPTING POINTS. ALSO, NEED TO ADJUST TCA AROUND THE 2000 FT TWRS TO ALLOW SAFE PASSAGE OVER OR AROUND IN LIMITED VISIBILITY.

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.