Narrative:

While flying in the traffic pattern with my student in small aircraft X, I heard an aircraft calling downwind entry. The small aircraft Y was coming tight and fast, and our small aircraft X was just starting to turn base leg. I told my student to lose altitude fast so the Y would fly above us if a conflict came about. We continued a normal pattern and called final approach. The Y immediately called final, and I began to scan west/O success. When we were over the threshold (about 30' AGL), I heard the engine of the Y and then saw the aircraft as it veered to the right and upward. It was dusk, and we had every light on. Note: I plugged the microphone into the wrong jack prior to this flight, therefore we were not transmitting--a fact not apparent until after the incident due to no traffic available in the pattern for a radio check. While reliable transmission would have contributed to flight safety, it should not be viewed as a crutch replacing the see and avoid concept. This was a simple case of a faster aircraft overtaking a slower aircraft while not exhibiting see and avoid.

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Original NASA ASRS Text

Title: SMA TRAINER IN TRAFFIC PATTERN BUT NOT TRANSMITTING ANNOUNCEMENTS DUE MIC JACK PLUGGED IN WRONG IS OVERTAKEN BY HIGHER PERFORMANCE ACFT RESULTING IN NMAC.

Narrative: WHILE FLYING IN THE TFC PATTERN WITH MY STUDENT IN SMA X, I HEARD AN ACFT CALLING DOWNWIND ENTRY. THE SMA Y WAS COMING TIGHT AND FAST, AND OUR SMA X WAS JUST STARTING TO TURN BASE LEG. I TOLD MY STUDENT TO LOSE ALT FAST SO THE Y WOULD FLY ABOVE US IF A CONFLICT CAME ABOUT. WE CONTINUED A NORMAL PATTERN AND CALLED FINAL APCH. THE Y IMMEDIATELY CALLED FINAL, AND I BEGAN TO SCAN W/O SUCCESS. WHEN WE WERE OVER THE THRESHOLD (ABOUT 30' AGL), I HEARD THE ENG OF THE Y AND THEN SAW THE ACFT AS IT VEERED TO THE RIGHT AND UPWARD. IT WAS DUSK, AND WE HAD EVERY LIGHT ON. NOTE: I PLUGGED THE MIC INTO THE WRONG JACK PRIOR TO THIS FLT, THEREFORE WE WERE NOT XMITTING--A FACT NOT APPARENT UNTIL AFTER THE INCIDENT DUE TO NO TFC AVAILABLE IN THE PATTERN FOR A RADIO CHK. WHILE RELIABLE XMISSION WOULD HAVE CONTRIBUTED TO FLT SAFETY, IT SHOULD NOT BE VIEWED AS A CRUTCH REPLACING THE SEE AND AVOID CONCEPT. THIS WAS A SIMPLE CASE OF A FASTER ACFT OVERTAKING A SLOWER ACFT WHILE NOT EXHIBITING SEE AND AVOID.

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.