Aircraft Y entered traffic pattern wrong had near midair collision with atx X. Pilot deviation.

Attributes
ACN	163997
Time
Date	199011
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zzz
State Reference	US
Altitude	agl bound lower : 1500 agl bound upper : 1500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : zzz
Operator	common carrier : air taxi
Make Model Name	Helicopter
Flight Phase	descent other
Flight Plan	VFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	other
Person 1
Affiliation	company : air taxi
Function	flight crew : single pilot
Qualification	pilot : atp
Experience	flight time last 90 days : 60 flight time total : 4000 flight time type : 500
ASRS Report	163997
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Events
Anomaly	conflict : nmac non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	none taken : insufficient time
Consequence	faa : investigated
Miss Distance	horizontal : 200 vertical : 0
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Town cleared atx X direct to the hospital downtown from the northeast. Tower pointed out 2 aircraft as traffic and I reported them in sight. Aircraft Y I had the incident with had reported 10 mi southeast for landing at ZZZ. He was told to report entering right downwind to runway 11. I knew there was a possible conflict at that time. Tower did not exchange traffic. Aircraft Y did not enter downwind on a 45 abeam the tower, but entered downwind straight. We met as he was entering downwind and I was descending to land at the hospital. After the incident, aircraft Y reported entering downwind. I informed tower that we had a near miss. Tower replied 'you are VFR.' hopefully this and other similar reports will help justify radar for ZZZ.

Original NASA ASRS Text

Title: ACFT Y ENTERED TRAFFIC PATTERN WRONG HAD NMAC WITH ATX X. PLTDEV.

Narrative: TOWN CLRED ATX X DIRECT TO THE HOSPITAL DOWNTOWN FROM THE NE. TWR POINTED OUT 2 ACFT AS TFC AND I RPTED THEM IN SIGHT. ACFT Y I HAD THE INCIDENT WITH HAD RPTED 10 MI SE FOR LNDG AT ZZZ. HE WAS TOLD TO RPT ENTERING R DOWNWIND TO RWY 11. I KNEW THERE WAS A POSSIBLE CONFLICT AT THAT TIME. TWR DID NOT EXCHANGE TFC. ACFT Y DID NOT ENTER DOWNWIND ON A 45 ABEAM THE TWR, BUT ENTERED DOWNWIND STRAIGHT. WE MET AS HE WAS ENTERING DOWNWIND AND I WAS DSNDING TO LAND AT THE HOSPITAL. AFTER THE INCIDENT, ACFT Y RPTED ENTERING DOWNWIND. I INFORMED TWR THAT WE HAD A NEAR MISS. TWR REPLIED 'YOU ARE VFR.' HOPEFULLY THIS AND OTHER SIMILAR RPTS WILL HELP JUSTIFY RADAR FOR ZZZ.

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.