Narrative:

14 NM north lhu began descent from 5500' MSL to 2000' MSL (1500' AGL). Heading 150 degrees. Called for unicom advisory on 122.7 10 NM north of lhu. Frequency congestion prevented hearing responses. Company advised wind calm along with temperature and altimeter (certified WX observation station). Also provides continuous traffic advisories along with unicom. We broadcast intentions on both 122.7 and 122.8. (Lhu recently switched from 122.8 to 122.7 to lessen congestion) 10 NM north stating who we were and that we intended to cross the airport at 2000' MSL (1500' AGL) to enter left downwind for runway 23. At approximately 4 NM north (area known as 'north shore') we made exact same traffic call on 122.7 and 122.8. At 1 NM north at 2000' MSL we initiated a pitch down maneuver to go under a converging aircraft. The aircraft was a single engine small aircraft at about 2000' MSL on a 230 degree heading. We had been converging on a 150 degree heading. After evading small aircraft we called our position as entering pattern. This we would have done at our evasion point had attention not been directed. Small aircraft was a left downwind departure from runway 5. He accused us of not listening, broadcasting and seeing for avoidance. We answered that we had made numerous xmissions and had never heard him. He was on correct frequency 122.7. We had not heard him and saw him at the very last. We were on an FAA approved pattern entry for lhu as per our poi at local FSDO. While both aircraft share equally in collision avoidance responsibility I believe the hazard lies in the high vol of traffic in the area with only unicom frequency and the resulting congestion and blocked xmissions. I believe the small aircraft did broadcast intentions but was covered. Small aircraft departed area to the west.

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Original NASA ASRS Text

Title: CLOSE PROX COMMUTER-LTT GA-SMA IN TRAFFIC PATTERN AT NON TWR ARPT USING UNICOM.

Narrative: 14 NM N LHU BEGAN DSCNT FROM 5500' MSL TO 2000' MSL (1500' AGL). HDG 150 DEGS. CALLED FOR UNICOM ADVISORY ON 122.7 10 NM N OF LHU. FREQ CONGESTION PREVENTED HEARING RESPONSES. COMPANY ADVISED WIND CALM ALONG WITH TEMP AND ALTIMETER (CERTIFIED WX OBSERVATION STATION). ALSO PROVIDES CONTINUOUS TFC ADVISORIES ALONG WITH UNICOM. WE BROADCAST INTENTIONS ON BOTH 122.7 AND 122.8. (LHU RECENTLY SWITCHED FROM 122.8 TO 122.7 TO LESSEN CONGESTION) 10 NM N STATING WHO WE WERE AND THAT WE INTENDED TO CROSS THE ARPT AT 2000' MSL (1500' AGL) TO ENTER LEFT DOWNWIND FOR RWY 23. AT APPROX 4 NM N (AREA KNOWN AS 'NORTH SHORE') WE MADE EXACT SAME TFC CALL ON 122.7 AND 122.8. AT 1 NM N AT 2000' MSL WE INITIATED A PITCH DOWN MANEUVER TO GO UNDER A CONVERGING ACFT. THE ACFT WAS A SINGLE ENG SMA AT ABOUT 2000' MSL ON A 230 DEG HDG. WE HAD BEEN CONVERGING ON A 150 DEG HDG. AFTER EVADING SMA WE CALLED OUR POS AS ENTERING PATTERN. THIS WE WOULD HAVE DONE AT OUR EVASION POINT HAD ATTN NOT BEEN DIRECTED. SMA WAS A LEFT DOWNWIND DEP FROM RWY 5. HE ACCUSED US OF NOT LISTENING, BROADCASTING AND SEEING FOR AVOIDANCE. WE ANSWERED THAT WE HAD MADE NUMEROUS XMISSIONS AND HAD NEVER HEARD HIM. HE WAS ON CORRECT FREQ 122.7. WE HAD NOT HEARD HIM AND SAW HIM AT THE VERY LAST. WE WERE ON AN FAA APPROVED PATTERN ENTRY FOR LHU AS PER OUR POI AT LCL FSDO. WHILE BOTH ACFT SHARE EQUALLY IN COLLISION AVOIDANCE RESPONSIBILITY I BELIEVE THE HAZARD LIES IN THE HIGH VOL OF TFC IN THE AREA WITH ONLY UNICOM FREQ AND THE RESULTING CONGESTION AND BLOCKED XMISSIONS. I BELIEVE THE SMA DID BROADCAST INTENTIONS BUT WAS COVERED. SMA DEPARTED AREA TO THE W.

Data retrieved from NASA's ASRS site as of August 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.