TCASII RA and airspace entry without clearance in pdx class C airspace.

Attributes
ACN	471155
Time
Date	200005
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : pdx.airport
State Reference	OR
Altitude	msl bound lower : 4000 msl bound upper : 4500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : p80.tracon
Operator	common carrier : air carrier
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	arrival : on vectors
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : p80.tracon
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : atp
Experience	flight time last 90 days : 150 flight time total : 10000 flight time type : 2000
ASRS Report	471155
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : multi engine pilot : commercial
Events
Anomaly	airspace violation : entry conflict : airborne critical non adherence : far other anomaly other
Independent Detector	aircraft equipment : tcas other controllerb other flight crewa
Resolutory Action	controller : issued advisory controller : issued new clearance
Miss Distance	horizontal : 3000 vertical : 0
Supplementary
Problem Areas	Flight Crew Human Performance Airspace Structure ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While being vectored for visual, cessna VFR traffic was called out at 4000 ft MSL. We advised ATC that traffic was not in sight. He held us up at 4500 ft MSL and turned us in to pass behind traffic. We then received a TCASII alert and RA to descend immediately. After complying with that, we received an additional RA to monitor vertical speed to avoid commuter traffic. We complied with that. Only at last min did we see VFR cessna traffic, but had commuter traffic in sight at all times. Supplemental information from ACN471156: air carrier descending north of pdx on downwind. I called VFR traffic and stopped it at 4500 ft. At the time, the VFR traffic was at 4000 ft. The VFR traffic continued to climb northeast. The air carrier verified that the traffic was a correct altitude readout. This aircraft had a transponder with mode C readouts, but was not talking to pdx approach. The VFR aircraft was in the class C airspace. If pdx had a class B airspace this near miss could have been possibly avoided, because the VFR aircraft would be required to call us.

Original NASA ASRS Text

Title: TCASII RA AND AIRSPACE ENTRY WITHOUT CLRNC IN PDX CLASS C AIRSPACE.

Narrative: WHILE BEING VECTORED FOR VISUAL, CESSNA VFR TFC WAS CALLED OUT AT 4000 FT MSL. WE ADVISED ATC THAT TFC WAS NOT IN SIGHT. HE HELD US UP AT 4500 FT MSL AND TURNED US IN TO PASS BEHIND TFC. WE THEN RECEIVED A TCASII ALERT AND RA TO DSND IMMEDIATELY. AFTER COMPLYING WITH THAT, WE RECEIVED AN ADDITIONAL RA TO MONITOR VERT SPD TO AVOID COMMUTER TFC. WE COMPLIED WITH THAT. ONLY AT LAST MIN DID WE SEE VFR CESSNA TFC, BUT HAD COMMUTER TFC IN SIGHT AT ALL TIMES. SUPPLEMENTAL INFO FROM ACN471156: ACR DSNDING N OF PDX ON DOWNWIND. I CALLED VFR TFC AND STOPPED IT AT 4500 FT. AT THE TIME, THE VFR TFC WAS AT 4000 FT. THE VFR TFC CONTINUED TO CLB NE. THE ACR VERIFIED THAT THE TFC WAS A CORRECT ALT READOUT. THIS ACFT HAD A XPONDER WITH MODE C READOUTS, BUT WAS NOT TALKING TO PDX APCH. THE VFR ACFT WAS IN THE CLASS C AIRSPACE. IF PDX HAD A CLASS B AIRSPACE THIS NEAR MISS COULD HAVE BEEN POSSIBLY AVOIDED, BECAUSE THE VFR ACFT WOULD BE REQUIRED TO CALL US.

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.