Narrative:

An A300 departed bwi runway 15R with a tower assigned heading of 330 degrees and climbing to 4;000 MSL. The aircraft filed the bwi TERPZ2 linden transition RNAV departure procedure. I radar identified the A300 and climbed the aircraft to 9;000 ft. When the aircraft was 2 miles south of bwi; I cleared the A300 'direct wonce; join the TERPZ2 departure' (wonce is the second way point; approximately 23 miles west of bwi on the TERPZ2). I subsequently re cleared the A300 to maintain 17;000 ft. After tending a few other tasks within the combined belay/wooly sectors; I scanned back to the A300 and noticed the aircraft was just slightly south of a direct track to wonce but the track history indicated a course towards wonce. I took care of a few other tasks and scanned back to the A300. At that time; the aircraft appeared to have turned westbound; still 10 miles from wonce; towards the krant sector responsible for iad/dca eastbound departures. I asked the A300 if he was still direct wonce; and the pilot responded 'affirmative'. When I traffic searched the krant sector; I noticed an A319; iad eastbound departure; slightly below and converging almost head on with the A300. I turned the A300 to a 310 heading and immediately called the traffic. The pilot reported the traffic in sight and then advised he had received a TCAS RA. I then noticed the A319 had immediately began descending and subsequently learned he had advised the washington center he was responding to a TCAS RA. The 310 heading was not enough to meet the lateral or visual separation requirements. When I queried the pilot as to why he wasn't direct wonce; he advised the aircraft's computer had started the turn. I have heard that boeing's and airbus's computer software are programmed differently when it comes to RNAV procedures. I've heard that incidents have occurred in the center structure where airbuses have turned early and tied up with other traffic. The A300 was not in center structure and only doing 260 KTS when his turned started. I clear aircraft direct wonce hundreds of times daily and; in my experience; no other aircraft; airbuses included; have ever turned that early. Additionally bwi has the ravnn RNAV arrival in which all the aircraft seem to cross over ravnn before turning to bwi. If this is truly an airbus software issue; then it needs to be addressed. If this is truly an airbus software issue; versus a pilot taking a shortcut; I would recommend that all airbus TERPZ2 departures be cleared direct to terpz instead of wonce to establish the aircraft on the departure procedure sooner. The flight track would be 1-2 miles away from the krant sector boundary and give a little more time to notice any flight deviation.

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Original NASA ASRS Text

Title: PCT Controller described a TCAS RA event allegedly caused by incorrect aircraft software route programming; the reporter suggesting Airbus software changes and filed route amendments.

Narrative: An A300 departed BWI Runway 15R with a Tower assigned heading of 330 degrees and climbing to 4;000 MSL. The aircraft filed the BWI TERPZ2 LINDEN transition RNAV departure procedure. I RADAR identified the A300 and climbed the aircraft to 9;000 FT. When the aircraft was 2 miles south of BWI; I cleared the A300 'direct WONCE; join the TERPZ2 departure' (WONCE is the second way point; approximately 23 miles west of BWI on the TERPZ2). I subsequently re cleared the A300 to maintain 17;000 FT. After tending a few other tasks within the combined Belay/Wooly Sectors; I scanned back to the A300 and noticed the aircraft was just slightly south of a direct track to WONCE but the track history indicated a course towards WONCE. I took care of a few other tasks and scanned back to the A300. At that time; the aircraft appeared to have turned westbound; still 10 miles from WONCE; towards the KRANT Sector responsible for IAD/DCA eastbound departures. I asked the A300 if he was still direct WONCE; and the pilot responded 'affirmative'. When I traffic searched the Krant Sector; I noticed an A319; IAD eastbound departure; slightly below and converging almost head on with the A300. I turned the A300 to a 310 heading and immediately called the traffic. The pilot reported the traffic in sight and then advised he had received a TCAS RA. I then noticed the A319 had immediately began descending and subsequently learned he had advised the Washington Center he was responding to a TCAS RA. The 310 heading was not enough to meet the lateral or visual separation requirements. When I queried the pilot as to why he wasn't direct WONCE; he advised the aircraft's computer had started the turn. I have heard that Boeing's and Airbus's computer software are programmed differently when it comes to RNAV procedures. I've heard that incidents have occurred in the Center structure where Airbuses have turned early and tied up with other traffic. The A300 was not in Center structure and only doing 260 KTS when his turned started. I clear aircraft direct WONCE hundreds of times daily and; in my experience; no other aircraft; Airbuses included; have ever turned that early. Additionally BWI has the RAVNN RNAV arrival in which all the aircraft seem to cross over RAVNN before turning to BWI. If this is truly an Airbus software issue; then it needs to be addressed. If this is truly an Airbus software issue; versus a pilot taking a shortcut; I would recommend that all Airbus TERPZ2 departures be cleared direct to TERPZ instead of WONCE to establish the aircraft on the departure procedure sooner. The flight track would be 1-2 miles away from the KRANT Sector boundary and give a little more time to notice any flight deviation.

Data retrieved from NASA's ASRS site as of April 2012 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.