Narrative:

I was PIC of small transport X. While in a left bank level turn from crosswind to downwind leg in the traffic pattern, another aircraft was observed as it flashed from right rear to left front slightly below our place. The left rear passenger observed the top of the plane as it passed below our plane at an angle. The plane, an small aircraft Y, was then observed out the left front window to make a right turn from a 45 degree entry leg to the downwind leg. The tower instructed small aircraft Y to make a right 360 degree turn. Immediately I called out on the tower frequency, 'no! You are turning the airplane directly into us!' I immediately nosed over as small aircraft Y began a right turn. The small aircraft Y pilot announced on the tower frequency that he would then make a 360 degree left turn. I continued on in the traffic pattern and landed. One should review the tape of the tower conversation with the small aircraft Y to determine what his instructions were, but from my observation, small aircraft Y was entering on a 45 degree to the downwind leg at an improper point. He should have been at midfield where both airplanes would have been in level flight. I was blind to his entry, being in a turn. I believe that pattern discipline at renton airport is poor, some caused by the tower operators permitting the poor habits to continue. A scheduled evening meeting once a week for 4 weeks until all users of renton airport are fully briefed should be considered. An accident will undoubtedly occur, given the current situation. A dialogue is needed.

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Original NASA ASRS Text

Title: CLOSE PROX GA-SMT GA-SMA IN RNT ATA.

Narrative: I WAS PIC OF SMT X. WHILE IN A LEFT BANK LEVEL TURN FROM XWIND TO DOWNWIND LEG IN THE TFC PATTERN, ANOTHER ACFT WAS OBSERVED AS IT FLASHED FROM RIGHT REAR TO LEFT FRONT SLIGHTLY BELOW OUR PLACE. THE LEFT REAR PAX OBSERVED THE TOP OF THE PLANE AS IT PASSED BELOW OUR PLANE AT AN ANGLE. THE PLANE, AN SMA Y, WAS THEN OBSERVED OUT THE LEFT FRONT WINDOW TO MAKE A RIGHT TURN FROM A 45 DEG ENTRY LEG TO THE DOWNWIND LEG. THE TWR INSTRUCTED SMA Y TO MAKE A RIGHT 360 DEG TURN. IMMEDIATELY I CALLED OUT ON THE TWR FREQ, 'NO! YOU ARE TURNING THE AIRPLANE DIRECTLY INTO US!' I IMMEDIATELY NOSED OVER AS SMA Y BEGAN A RIGHT TURN. THE SMA Y PLT ANNOUNCED ON THE TWR FREQ THAT HE WOULD THEN MAKE A 360 DEG LEFT TURN. I CONTINUED ON IN THE TFC PATTERN AND LANDED. ONE SHOULD REVIEW THE TAPE OF THE TWR CONVERSATION WITH THE SMA Y TO DETERMINE WHAT HIS INSTRUCTIONS WERE, BUT FROM MY OBSERVATION, SMA Y WAS ENTERING ON A 45 DEG TO THE DOWNWIND LEG AT AN IMPROPER POINT. HE SHOULD HAVE BEEN AT MIDFIELD WHERE BOTH AIRPLANES WOULD HAVE BEEN IN LEVEL FLT. I WAS BLIND TO HIS ENTRY, BEING IN A TURN. I BELIEVE THAT PATTERN DISCIPLINE AT RENTON ARPT IS POOR, SOME CAUSED BY THE TWR OPERATORS PERMITTING THE POOR HABITS TO CONTINUE. A SCHEDULED EVENING MEETING ONCE A WK FOR 4 WKS UNTIL ALL USERS OF RENTON ARPT ARE FULLY BRIEFED SHOULD BE CONSIDERED. AN ACCIDENT WILL UNDOUBTEDLY OCCUR, GIVEN THE CURRENT SITUATION. A DIALOGUE IS NEEDED.

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.