Narrative:

The other aircraft was on a practice ILS approach to runway 14 and gave his position on the ILS. There were 4 aircraft in the pattern. I entered downwind at the 45 degree entry; south of ILS to active runway 1; at pattern altitude and reported my position. I had a visual on the piper aircraft until on downwind; I reported my position on downwind with my intent to make a full stop landing. While extending the gear and flaps; the piper pilot reported that he intended making a 270 degree turn and enter downwind for landing runway 1. After extending flaps to 20 degrees; I reported turning downwind to base runway 1; and started descending turn to base. During this turn the piper pilot reported that he was on left base landing runway 1. I raised the wing and observed the piper aircraft in a descending turn inside and below my position. I took evasive action while he continued his approach and landing. Cause: the flight instructor and student on a practice approach; at the middle marker; turned right; and climbed in the downwind traffic pattern. The instructor did not make the 270 degree turn as he stated; did not attain pattern altitude or maintain aircraft separation. Prevention: instructor pilots should teach and use standard procedures at uncontrolled airports.

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Original NASA ASRS Text

Title: A C210 PLT EVADED A PA28 ON A PRACTICE ILS IN A CTAF TFC PATTERN AT CXO.

Narrative: THE OTHER ACFT WAS ON A PRACTICE ILS APCH TO RWY 14 AND GAVE HIS POS ON THE ILS. THERE WERE 4 ACFT IN THE PATTERN. I ENTERED DOWNWIND AT THE 45 DEG ENTRY; S OF ILS TO ACTIVE RWY 1; AT PATTERN ALT AND RPTED MY POS. I HAD A VISUAL ON THE PIPER ACFT UNTIL ON DOWNWIND; I RPTED MY POS ON DOWNWIND WITH MY INTENT TO MAKE A FULL STOP LNDG. WHILE EXTENDING THE GEAR AND FLAPS; THE PIPER PLT RPTED THAT HE INTENDED MAKING A 270 DEG TURN AND ENTER DOWNWIND FOR LNDG RWY 1. AFTER EXTENDING FLAPS TO 20 DEGS; I RPTED TURNING DOWNWIND TO BASE RWY 1; AND STARTED DSNDING TURN TO BASE. DURING THIS TURN THE PIPER PLT RPTED THAT HE WAS ON L BASE LNDG RWY 1. I RAISED THE WING AND OBSERVED THE PIPER ACFT IN A DSNDING TURN INSIDE AND BELOW MY POS. I TOOK EVASIVE ACTION WHILE HE CONTINUED HIS APCH AND LNDG. CAUSE: THE FLT INSTRUCTOR AND STUDENT ON A PRACTICE APCH; AT THE MIDDLE MARKER; TURNED R; AND CLBED IN THE DOWNWIND TFC PATTERN. THE INSTRUCTOR DID NOT MAKE THE 270 DEG TURN AS HE STATED; DID NOT ATTAIN PATTERN ALT OR MAINTAIN ACFT SEPARATION. PREVENTION: INSTRUCTOR PLTS SHOULD TEACH AND USE STANDARD PROCS AT UNCTLED ARPTS.

Data retrieved from NASA's ASRS site as of January 2009 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.