Medium large transport has TCASII RA on descent, probably false.

Attributes
ACN	299315
Time
Date	199503
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : btg
State Reference	WA
Altitude	msl bound lower : 10000 msl bound upper : 13000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zse artcc : zlc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent other
Route In Use	arrival other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 164 flight time total : 14300 flight time type : 4323
ASRS Report	299315
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : undershoot non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

En route to pdx we were cleared to pdx via moxee 3 arrival to cross flowr intersection at 10000 ft, 250 KIAS. Descending through 13000 ft, the TCASII suddenly advised of an RA. I immediately leveled at 12800 ft and followed the TCASII monitor vertical speed commands back up to 13000 ft. The first officer called center asking if we had traffic at 12 O'clock. The center told us we had been switched to approach a few mi back (a call we had not responded to) and to switch to 118.1. While switching to 118.1 the TCASII traffic disappeared. We checked in with pdx approach control reporting 13000 ft for 10000 ft. Approach control gave us a heading and lower altitude. The center frequency was busy and it was hard to get a word in to advise of the RA when it happened. The TCASII traffic showed between 400 ft and 500 ft below us at 12 O'clock. We were in VFR conditions at the time and both looking out to get visual contact. No visual contact was made leading me to believe this was a false RA because of the sudden appearance and disappearance of the traffic on the TCASII screen. There was no mention of any conflicting air traffic by ATC or any mention of the RA and leveloff at 13000 ft by us because air traffic control was busy.

Original NASA ASRS Text

Title: MLG HAS TCASII RA ON DSCNT, PROBABLY FALSE.

Narrative: ENRTE TO PDX WE WERE CLRED TO PDX VIA MOXEE 3 ARR TO CROSS FLOWR INTXN AT 10000 FT, 250 KIAS. DSNDING THROUGH 13000 FT, THE TCASII SUDDENLY ADVISED OF AN RA. I IMMEDIATELY LEVELED AT 12800 FT AND FOLLOWED THE TCASII MONITOR VERT SPD COMMANDS BACK UP TO 13000 FT. THE FO CALLED CTR ASKING IF WE HAD TFC AT 12 O'CLOCK. THE CTR TOLD US WE HAD BEEN SWITCHED TO APCH A FEW MI BACK (A CALL WE HAD NOT RESPONDED TO) AND TO SWITCH TO 118.1. WHILE SWITCHING TO 118.1 THE TCASII TFC DISAPPEARED. WE CHKED IN WITH PDX APCH CTL RPTING 13000 FT FOR 10000 FT. APCH CTL GAVE US A HDG AND LOWER ALT. THE CTR FREQ WAS BUSY AND IT WAS HARD TO GET A WORD IN TO ADVISE OF THE RA WHEN IT HAPPENED. THE TCASII TFC SHOWED BTWN 400 FT AND 500 FT BELOW US AT 12 O'CLOCK. WE WERE IN VFR CONDITIONS AT THE TIME AND BOTH LOOKING OUT TO GET VISUAL CONTACT. NO VISUAL CONTACT WAS MADE LEADING ME TO BELIEVE THIS WAS A FALSE RA BECAUSE OF THE SUDDEN APPEARANCE AND DISAPPEARANCE OF THE TFC ON THE TCASII SCREEN. THERE WAS NO MENTION OF ANY CONFLICTING AIR TFC BY ATC OR ANY MENTION OF THE RA AND LEVELOFF AT 13000 FT BY US BECAUSE AIR TFC CTL WAS BUSY.

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.