Narrative:

After completing 3 successful patterns and making the necessary radio calls, we called 'boca traffic (small aircraft X), left downwind runway 5 boca raton.' as we approached approximately midfield left downwind runway 5, the small transport Y requested TA, he received 'runway 5, left traffic.' we then proceeded to set up for the touch-and-go. Abeam the numbers, we began our descent. As we began to turn left base to runway 5, I made the call, 'boca traffic (small aircraft sel X) turning left base runway 5 boca raton.' at approximately 600 ft we began the turn to final, 'boca traffic (sel X) turning final runway 5 boca raton.' after this transmission, the small transport reported 'small transport number, left downwind runway 5 at boca.' at this point, I found it strange that the small transport had entered a left downwind so quickly after his initial radio call. I looked for him on downwind but could not see him. Approximately 10 seconds later he called 'final runway 5 at boca.' no base leg call. At this point, a radioed 'boca, small aircraft short finals runway 5 at boca, small transport position reports.' no answer. I frantically looked to the rear in the small transport sel to see him approach overhead at not more than 5 ft. Luckily, my student had dropped slightly low on the glide path. If not, a midair collision would definitely have resulted. I believe this exacerbated the situation: 1) pilots do not make their TA calls far enough from uncontrolled fields. 2) make wrong entries. 3) do not monitor CTAF well enough. He also broke far 91.113(G) landing aircraft. Several witnesses also found the same fault with the small transport.

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Original NASA ASRS Text

Title: NMAC. SMT TWIN ENG ACFT OVERTAKES AN SMA SEL TRAINING ACFT ON SHORT FINAL AT AN UNCTLED ARPT.

Narrative: AFTER COMPLETING 3 SUCCESSFUL PATTERNS AND MAKING THE NECESSARY RADIO CALLS, WE CALLED 'BOCA TFC (SMA X), L DOWNWIND RWY 5 BOCA RATON.' AS WE APCHED APPROX MIDFIELD L DOWNWIND RWY 5, THE SMT Y REQUESTED TA, HE RECEIVED 'RWY 5, L TFC.' WE THEN PROCEEDED TO SET UP FOR THE TOUCH-AND-GO. ABEAM THE NUMBERS, WE BEGAN OUR DSCNT. AS WE BEGAN TO TURN L BASE TO RWY 5, I MADE THE CALL, 'BOCA TFC (SMA SEL X) TURNING L BASE RWY 5 BOCA RATON.' AT APPROX 600 FT WE BEGAN THE TURN TO FINAL, 'BOCA TFC (SEL X) TURNING FINAL RWY 5 BOCA RATON.' AFTER THIS XMISSION, THE SMT RPTED 'SMT NUMBER, L DOWNWIND RWY 5 AT BOCA.' AT THIS POINT, I FOUND IT STRANGE THAT THE SMT HAD ENTERED A L DOWNWIND SO QUICKLY AFTER HIS INITIAL RADIO CALL. I LOOKED FOR HIM ON DOWNWIND BUT COULD NOT SEE HIM. APPROX 10 SECONDS LATER HE CALLED 'FINAL RWY 5 AT BOCA.' NO BASE LEG CALL. AT THIS POINT, A RADIOED 'BOCA, SMA SHORT FINALS RWY 5 AT BOCA, SMT POS RPTS.' NO ANSWER. I FRANTICALLY LOOKED TO THE REAR IN THE SMT SEL TO SEE HIM APCH OVERHEAD AT NOT MORE THAN 5 FT. LUCKILY, MY STUDENT HAD DROPPED SLIGHTLY LOW ON THE GLIDE PATH. IF NOT, A MIDAIR COLLISION WOULD DEFINITELY HAVE RESULTED. I BELIEVE THIS EXACERBATED THE SIT: 1) PLTS DO NOT MAKE THEIR TA CALLS FAR ENOUGH FROM UNCTLED FIELDS. 2) MAKE WRONG ENTRIES. 3) DO NOT MONITOR CTAF WELL ENOUGH. HE ALSO BROKE FAR 91.113(G) LNDG ACFT. SEVERAL WITNESSES ALSO FOUND THE SAME FAULT WITH THE SMT.

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.