Near midair collision between 2 GA-small aircraft's on final approach to airport.

Attributes
ACN	83108
Time
Date	198803
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : gxy
State Reference	CO
Altitude	msl bound lower : 6000 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	None
Aircraft 2
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 30 flight time total : 850 flight time type : 800
ASRS Report	83108
Person 2
Function	flight crew : single pilot
Qualification	pilot : private
Events
Anomaly	conflict : nmac non adherence : published procedure other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action other
Consequence	Other
Miss Distance	horizontal : 50 vertical : 200
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other
Situations
ATC Facility	other physical facility

Narrative:

Greeley-weld county airport is an extremely busy uncontrolled field, with several major flight training schools operating 7 days/week. Called unicom for airport advisory approximately 10 mi out, monitored traffic and announced position entering downwind, base and final. No traffic ahead of me except a no-radio small aircraft X. Scanned up long final before turning final and saw no other traffic. After T/D, an small aircraft Y overflew me and called to complain that I'd cut him off an a straight in approach. Told him his radio was extremely weak and I hadn't heard him report or seen his aircraft (difficult viewing area with mottled background of city bldgs). An small aircraft Z in the pattern confirmed small aircraft Y radio weak, mostly static. Concensus of pilots who use that airport regularly is that it is foolhardy to make a straight in approach rather than fly full pattern from mid field downwind entry. This airport really needs an ATC tower.

Original NASA ASRS Text

Title: NMAC BETWEEN 2 GA-SMA'S ON FINAL APCH TO ARPT.

Narrative: GREELEY-WELD COUNTY ARPT IS AN EXTREMELY BUSY UNCTLED FIELD, WITH SEVERAL MAJOR FLT TRNING SCHOOLS OPERATING 7 DAYS/WK. CALLED UNICOM FOR ARPT ADVISORY APPROX 10 MI OUT, MONITORED TFC AND ANNOUNCED POS ENTERING DOWNWIND, BASE AND FINAL. NO TFC AHEAD OF ME EXCEPT A NO-RADIO SMA X. SCANNED UP LONG FINAL BEFORE TURNING FINAL AND SAW NO OTHER TFC. AFTER T/D, AN SMA Y OVERFLEW ME AND CALLED TO COMPLAIN THAT I'D CUT HIM OFF AN A STRAIGHT IN APCH. TOLD HIM HIS RADIO WAS EXTREMELY WEAK AND I HADN'T HEARD HIM RPT OR SEEN HIS ACFT (DIFFICULT VIEWING AREA WITH MOTTLED BACKGROUND OF CITY BLDGS). AN SMA Z IN THE PATTERN CONFIRMED SMA Y RADIO WEAK, MOSTLY STATIC. CONCENSUS OF PLTS WHO USE THAT ARPT REGULARLY IS THAT IT IS FOOLHARDY TO MAKE A STRAIGHT IN APCH RATHER THAN FLY FULL PATTERN FROM MID FIELD DOWNWIND ENTRY. THIS ARPT REALLY NEEDS AN ATC TWR.

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.