Narrative:

I was flying a PA31-310 (navajo) on a visual approach to runway 8. My flight plan was to fly V15 from bis to mot at 6000 ft MSL. At 20 mi from mot; the controller had me fly a heading of 320 degrees; then 310 degrees; then 340 degrees; then 040 degrees and intercept the final approach course of 080 degrees to land on runway 8. At the same time a DC9 was vectored over the mot VORTAC and entered a right downwind for runway 8. I reported I had the DC9 in sight. I then lost the DC9 and asked the tower where the DC9 was. Tower said 'on base.' I told him I didn't have the DC9 in sight. A few moments later; I saw the DC9 about 500 ft below me and off to my 2 O'clock position. We were both about 4 mi out; on final. I immediately turned from 080 degrees to 330 degrees and climbed from 4000 ft MSL to 5000 ft MSL. The DC9 did a right 360 degree turn and came back in to land ahead of me. He was about 500 ft below. I called the tower after landing and expressed my concern and confusion over what happened. I wonder if I didn't understand a vector; or missed a call from ATC or what. It scared me.

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Original NASA ASRS Text

Title: IFR PA31 ON VISUAL APCH TO MOT RWY 8 EXPERIENCED CONFLICT WITH PRECEDING DC9 ON APCH TO SAME RWY.

Narrative: I WAS FLYING A PA31-310 (NAVAJO) ON A VISUAL APCH TO RWY 8. MY FLT PLAN WAS TO FLY V15 FROM BIS TO MOT AT 6000 FT MSL. AT 20 MI FROM MOT; THE CTLR HAD ME FLY A HDG OF 320 DEGS; THEN 310 DEGS; THEN 340 DEGS; THEN 040 DEGS AND INTERCEPT THE FINAL APCH COURSE OF 080 DEGS TO LAND ON RWY 8. AT THE SAME TIME A DC9 WAS VECTORED OVER THE MOT VORTAC AND ENTERED A R DOWNWIND FOR RWY 8. I RPTED I HAD THE DC9 IN SIGHT. I THEN LOST THE DC9 AND ASKED THE TWR WHERE THE DC9 WAS. TWR SAID 'ON BASE.' I TOLD HIM I DIDN'T HAVE THE DC9 IN SIGHT. A FEW MOMENTS LATER; I SAW THE DC9 ABOUT 500 FT BELOW ME AND OFF TO MY 2 O'CLOCK POS. WE WERE BOTH ABOUT 4 MI OUT; ON FINAL. I IMMEDIATELY TURNED FROM 080 DEGS TO 330 DEGS AND CLBED FROM 4000 FT MSL TO 5000 FT MSL. THE DC9 DID A R 360 DEG TURN AND CAME BACK IN TO LAND AHEAD OF ME. HE WAS ABOUT 500 FT BELOW. I CALLED THE TWR AFTER LNDG AND EXPRESSED MY CONCERN AND CONFUSION OVER WHAT HAPPENED. I WONDER IF I DIDN'T UNDERSTAND A VECTOR; OR MISSED A CALL FROM ATC OR WHAT. IT SCARED ME.

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.