A pilot reported an near midair collision with a cessna in the fdk traffic pattern. The cessna pilot...

Narrative:

While approaching frederick muni (fdk) I checked ATIS several times beginning from 20 miles out. The wind was 030 at 4-9; favoring runway 5. I monitored the CTAF from 20 miles out; and all aircraft were using runway 5. Additionally; one landing aircraft called unicom for recommended runway; and was told runway 5. I reported ten and five miles out for a right downwind entry to runway 5; which is the standard pattern for this runway. I then heard a cessna report left base for runway 23; and no other calls from this aircraft. I reported entry to the right pattern for runway 5 and 'right midfield downwind; landing five.' at that point I heard the cessna report left downwind for runway 23 and immediately saw him pass from my 1:00; then off my right wingtip at less than 500 feet and at the same altitude of 1300 feet (standard pattern altitude for fdk). I radioed the cessna and asked him if he saw me as he passed. He stated he saw a helicopter on the other side of the field. I then radioed that he was flying opposite to the recommended winds for landing and that we had just had a near miss. He radioed 'okie-dokie.' a king air awaiting takeoff radioed asking the cessna 'why are you going the wrong way?' the cessna did not reply; was not heard on the frequency again; and did not land. I landed without further incident.

Original NASA ASRS Text

Title: A Pilot reported an NMAC with a Cessna in the FDK traffic pattern. The Cessna pilot had entered a left downwind for Runway 23; while the other aircraft in the pattern were making right traffic for Runway 5.

Narrative: While approaching Frederick Muni (FDK) I checked ATIS several times beginning from 20 miles out. The wind was 030 at 4-9; favoring Runway 5. I monitored the CTAF from 20 miles out; and all aircraft were using Runway 5. Additionally; one landing aircraft called Unicom for recommended runway; and was told Runway 5. I reported ten and five miles out for a right downwind entry to Runway 5; which is the standard pattern for this runway. I then heard a Cessna report left base for Runway 23; and no other calls from this aircraft. I reported entry to the right pattern for Runway 5 and 'right midfield downwind; landing five.' At that point I heard the Cessna report left downwind for Runway 23 and immediately saw him pass from my 1:00; then off my right wingtip at less than 500 feet and at the same altitude of 1300 feet (standard pattern altitude for FDK). I radioed the Cessna and asked him if he saw me as he passed. He stated he saw a helicopter on the other side of the field. I then radioed that he was flying opposite to the recommended winds for landing and that we had just had a near miss. He radioed 'okie-dokie.' A King Air awaiting takeoff radioed asking the Cessna 'why are you going the wrong way?' The Cessna did not reply; was not heard on the frequency again; and did not land. I landed without further incident.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	970521
Time
Date	201109
Local Time Of Day	1201-1800
Place
Locale Reference	FDK.Airport
State Reference	MD
Aircraft 1
Make Model Name	Experimental
Operating Under FAR Part	Part 91
Flight Phase	Landing
Route In Use	Direct
Flight Plan	None
Aircraft 2
Make Model Name	Cessna Single Piston Undifferentiated or Other Model
Person 1
Function	Single Pilot Pilot Flying
Qualification	Flight Crew Instrument Flight Crew Private
Experience	Flight Crew Last 90 Days 15 Flight Crew Total 1200 Flight Crew Type 350
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 500 Vertical 0

A pilot reported an near midair collision with a cessna in the fdk traffic pattern. The cessna pilot had entered a left downwind for runway 23; while the other aircraft in the pattern were making right traffic for runway 5.