Small transport has near midair collision with small aircraft in traffic pattern.

Attributes
ACN	314980
Time
Date	199509
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : 4ac
State Reference	NM
Altitude	msl bound lower : 6600 msl bound upper : 6600
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : corporate
Make Model Name	PA-31 Navajo Chieftan/Mojave/Navajo T1020
Operating Under FAR Part	Part 91
Flight Phase	other
Flight Plan	None
Aircraft 2
Operator	general aviation : instructional
Make Model Name	Cessna Aircraft Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	other
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : atp
Experience	flight time last 90 days : 50 flight time total : 9000 flight time type : 2000
ASRS Report	314980
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Events
Anomaly	conflict : nmac other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 300 vertical : 200
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I called coronado airport for an airport advisory, I stated I was 10 mi north. They responded 'winds were light and variable -- landing runway 35, left traffic.' within 30 seconds I heard a cessna call crosswind for runway 35. He then called downwind for runway 35 about 30 seconds later. At this time I was about 8 mi north. A few mins later I called on 122.8 that I was 2 mi northwest entering a left downwind for runway 35. I was looking for cessna to be well on the downwind or on base by this time. As I was approaching the north end of runway 35 on downwind I saw him under me and to my left. At this time he called me and said that I went right over him. I checked my altitude and was at 6600 ft. I was turning base, he called me and asked why I didn't report position. I told him that I had reported 2 mi northwest after he had called downwind. As I was on final he called reporting he was leaving the pattern to the west. This airport has a lot of student traffic and I am quite aware of this as I fly into this airport once a week for the last 9 yrs. I have found that student/instructors will turn the volume down until they need to talk on the radio. This is a very unsafe condition and not good practice to teach students if this was the case.

Original NASA ASRS Text

Title: SMT HAS NMAC WITH SMA IN TFC PATTERN.

Narrative: I CALLED CORONADO ARPT FOR AN ARPT ADVISORY, I STATED I WAS 10 MI N. THEY RESPONDED 'WINDS WERE LIGHT AND VARIABLE -- LNDG RWY 35, L TFC.' WITHIN 30 SECONDS I HEARD A CESSNA CALL XWIND FOR RWY 35. HE THEN CALLED DOWNWIND FOR RWY 35 ABOUT 30 SECONDS LATER. AT THIS TIME I WAS ABOUT 8 MI N. A FEW MINS LATER I CALLED ON 122.8 THAT I WAS 2 MI NW ENTERING A L DOWNWIND FOR RWY 35. I WAS LOOKING FOR CESSNA TO BE WELL ON THE DOWNWIND OR ON BASE BY THIS TIME. AS I WAS APCHING THE N END OF RWY 35 ON DOWNWIND I SAW HIM UNDER ME AND TO MY L. AT THIS TIME HE CALLED ME AND SAID THAT I WENT RIGHT OVER HIM. I CHKED MY ALT AND WAS AT 6600 FT. I WAS TURNING BASE, HE CALLED ME AND ASKED WHY I DIDN'T RPT POS. I TOLD HIM THAT I HAD RPTED 2 MI NW AFTER HE HAD CALLED DOWNWIND. AS I WAS ON FINAL HE CALLED RPTING HE WAS LEAVING THE PATTERN TO THE W. THIS ARPT HAS A LOT OF STUDENT TFC AND I AM QUITE AWARE OF THIS AS I FLY INTO THIS ARPT ONCE A WK FOR THE LAST 9 YRS. I HAVE FOUND THAT STUDENT/INSTRUCTORS WILL TURN THE VOLUME DOWN UNTIL THEY NEED TO TALK ON THE RADIO. THIS IS A VERY UNSAFE CONDITION AND NOT GOOD PRACTICE TO TEACH STUDENTS IF THIS WAS THE CASE.

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.