Small aircraft entering pattern has close proximity with another aircraft.

Attributes
ACN	184303
Time
Date	199107
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : cos
State Reference	CO
Altitude	agl bound lower : 800 agl bound upper : 1000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : cos
Operator	other
Make Model Name	Small Aircraft
Flight Phase	other
Flight Plan	VFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Person 1
Affiliation	government other
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 50 flight time total : 9000 flight time type : 200
ASRS Report	184303
Person 2
Affiliation	government other
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical conflict : airborne less severe non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 900 vertical : 250
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Had been following another aircraft to the airport from 19 mi out, was instructed by approach to follow the aircraft. Upon approaching air traffic area I lost sight of the other aircraft. I was told to turn left to heading 070 for left base to 35 and contact tower. I turned left to 070 then contacted tower. Was told other aircraft was on short left base, no factor cleared to land. I acknowledged clearance. At this time I noticed a second aircraft which appeared to be in a downwind about 250 ft below me and approximately 900 ft horizontal. The last and only transmission I heard was traffic on short left base no factor cleared to land. Upon landing tower asked if I had heard any of their xmissions since they had been calling. I told them negative. Probable cause of not hearing their subsequent xmissions was a stuck microphone. On a subsequent flight by another pilot in the same aircraft, the microphone button on a push-to-talk switch stuck twice.

Original NASA ASRS Text

Title: SMA ENTERING PATTERN HAS CLOSE PROX WITH ANOTHER ACFT.

Narrative: HAD BEEN FOLLOWING ANOTHER ACFT TO THE ARPT FROM 19 MI OUT, WAS INSTRUCTED BY APCH TO FOLLOW THE ACFT. UPON APCHING ATA I LOST SIGHT OF THE OTHER ACFT. I WAS TOLD TO TURN L TO HDG 070 FOR L BASE TO 35 AND CONTACT TWR. I TURNED L TO 070 THEN CONTACTED TWR. WAS TOLD OTHER ACFT WAS ON SHORT L BASE, NO FACTOR CLRED TO LAND. I ACKNOWLEDGED CLRNC. AT THIS TIME I NOTICED A SECOND ACFT WHICH APPEARED TO BE IN A DOWNWIND ABOUT 250 FT BELOW ME AND APPROX 900 FT HORIZ. THE LAST AND ONLY XMISSION I HEARD WAS TFC ON SHORT L BASE NO FACTOR CLRED TO LAND. UPON LNDG TWR ASKED IF I HAD HEARD ANY OF THEIR XMISSIONS SINCE THEY HAD BEEN CALLING. I TOLD THEM NEGATIVE. PROBABLE CAUSE OF NOT HEARING THEIR SUBSEQUENT XMISSIONS WAS A STUCK MICROPHONE. ON A SUBSEQUENT FLT BY ANOTHER PLT IN THE SAME ACFT, THE MICROPHONE BUTTON ON A PUSH-TO-TALK SWITCH STUCK TWICE.

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.