Narrative:

I was approaching pdx from the north. An air carrier flight was approaching from the south. I was told by ATC to expect runway 28L and follow air carrier X. I was about 2 mi east of the 'mill', a landmark used by ATC, when I decided to request runway 28R to expedite my arrival. I made my request with ATC and they granted it, with no conditions. The other flight was cleared for the mill visual. Mindful of the fact that the other air carrier will turn towards the airport over the columbia river, I planned my approach accordingly. I was high so I expedited my descent and turned directly towards runway 28R. This flight path will parallel the mill visual by about 1/2-3/4 mi on about a 240 degree heading, thus ensuring lateral separation. I was about 1/2 mi north of the mill established on my track, north of the north bank of the columbia river, when a crew member in the other air carrier flight made a query regarding my aircraft position with ATC. ATC called me asking if I had the aircraft in sight, which I replied, I did. ATC asked if I was familiar with the mill visual, I replied, I was. The air carrier crew commented with words to the effect that I perhaps did not. I made a statement to ATC that I was maintaining visual separation. The other crew said that I had set off their TCASII and 'various alarms.' both aircraft landed without incident. I maintain that a collision hazard was not caused, I had visual separation throughout the approach. To the best of my knowledge, when cleared for the visual, I was told to maintain visual separation. ATC gave me no special instructions or noise abatement protocols to comply with during the approach. I suspect ATC did not expect me to turn directly to the runway 28R threshold. Perhaps they thought I would turn behind the other air carrier, but a more typical right base to final would have put me on a final approach to runway 28R with other aircraft in front and to my right, thus they would have crossed my path. That's why I felt my direct turn to runway 28R, with an expedited descent, would remove the crossing dilemma by flying a parallel course. At night you only see the other aircraft's lights, so it is harder to determine the true flight path. This probably set up the illusion on the part of the crew that I was flying towards them, when in fact that was not the case. When the crew made their initial comment about me I was already on final and lower than them. They had not made their turn to final so there was probably the appearance that we were still converging which led to their concern. In the terminal environment with aircraft getting closer, the incidence of TCASII alarms increase. It was not my intent to cause alert or distress to the crew or ATC. To minimize this from occurring again I will plan to turn behind aircraft and also seek clarification from ATC if I think a separation issue might occur.

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Original NASA ASRS Text

Title: A B1900 APCHING PDX FROM THE N MAKES A VISUAL APCH TO RWY 28R AND PARALLELS AN ACR INBOUND FROM THE S ON THE MILL VISUAL TO RWY 28L.

Narrative: I WAS APCHING PDX FROM THE N. AN ACR FLT WAS APCHING FROM THE S. I WAS TOLD BY ATC TO EXPECT RWY 28L AND FOLLOW ACR X. I WAS ABOUT 2 MI E OF THE 'MILL', A LANDMARK USED BY ATC, WHEN I DECIDED TO REQUEST RWY 28R TO EXPEDITE MY ARR. I MADE MY REQUEST WITH ATC AND THEY GRANTED IT, WITH NO CONDITIONS. THE OTHER FLT WAS CLRED FOR THE MILL VISUAL. MINDFUL OF THE FACT THAT THE OTHER ACR WILL TURN TOWARDS THE ARPT OVER THE COLUMBIA RIVER, I PLANNED MY APCH ACCORDINGLY. I WAS HIGH SO I EXPEDITED MY DSCNT AND TURNED DIRECTLY TOWARDS RWY 28R. THIS FLT PATH WILL PARALLEL THE MILL VISUAL BY ABOUT 1/2-3/4 MI ON ABOUT A 240 DEG HDG, THUS ENSURING LATERAL SEPARATION. I WAS ABOUT 1/2 MI N OF THE MILL ESTABLISHED ON MY TRACK, N OF THE NORTH BANK OF THE COLUMBIA RIVER, WHEN A CREW MEMBER IN THE OTHER ACR FLT MADE A QUERY REGARDING MY ACFT POS WITH ATC. ATC CALLED ME ASKING IF I HAD THE ACFT IN SIGHT, WHICH I REPLIED, I DID. ATC ASKED IF I WAS FAMILIAR WITH THE MILL VISUAL, I REPLIED, I WAS. THE ACR CREW COMMENTED WITH WORDS TO THE EFFECT THAT I PERHAPS DID NOT. I MADE A STATEMENT TO ATC THAT I WAS MAINTAINING VISUAL SEPARATION. THE OTHER CREW SAID THAT I HAD SET OFF THEIR TCASII AND 'VARIOUS ALARMS.' BOTH ACFT LANDED WITHOUT INCIDENT. I MAINTAIN THAT A COLLISION HAZARD WAS NOT CAUSED, I HAD VISUAL SEPARATION THROUGHOUT THE APCH. TO THE BEST OF MY KNOWLEDGE, WHEN CLRED FOR THE VISUAL, I WAS TOLD TO MAINTAIN VISUAL SEPARATION. ATC GAVE ME NO SPECIAL INSTRUCTIONS OR NOISE ABATEMENT PROTOCOLS TO COMPLY WITH DURING THE APCH. I SUSPECT ATC DID NOT EXPECT ME TO TURN DIRECTLY TO THE RWY 28R THRESHOLD. PERHAPS THEY THOUGHT I WOULD TURN BEHIND THE OTHER ACR, BUT A MORE TYPICAL R BASE TO FINAL WOULD HAVE PUT ME ON A FINAL APCH TO RWY 28R WITH OTHER ACFT IN FRONT AND TO MY R, THUS THEY WOULD HAVE CROSSED MY PATH. THAT'S WHY I FELT MY DIRECT TURN TO RWY 28R, WITH AN EXPEDITED DSCNT, WOULD REMOVE THE XING DILEMMA BY FLYING A PARALLEL COURSE. AT NIGHT YOU ONLY SEE THE OTHER ACFT'S LIGHTS, SO IT IS HARDER TO DETERMINE THE TRUE FLT PATH. THIS PROBABLY SET UP THE ILLUSION ON THE PART OF THE CREW THAT I WAS FLYING TOWARDS THEM, WHEN IN FACT THAT WAS NOT THE CASE. WHEN THE CREW MADE THEIR INITIAL COMMENT ABOUT ME I WAS ALREADY ON FINAL AND LOWER THAN THEM. THEY HAD NOT MADE THEIR TURN TO FINAL SO THERE WAS PROBABLY THE APPEARANCE THAT WE WERE STILL CONVERGING WHICH LED TO THEIR CONCERN. IN THE TERMINAL ENVIRONMENT WITH ACFT GETTING CLOSER, THE INCIDENCE OF TCASII ALARMS INCREASE. IT WAS NOT MY INTENT TO CAUSE ALERT OR DISTRESS TO THE CREW OR ATC. TO MINIMIZE THIS FROM OCCURRING AGAIN I WILL PLAN TO TURN BEHIND ACFT AND ALSO SEEK CLARIFICATION FROM ATC IF I THINK A SEPARATION ISSUE MIGHT OCCUR.

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.