B737-300 was vectored below the phx class B airspace at 4000 ft. They got a GPWS 'terrain' warning.

Attributes
ACN	577253
Time
Date	200303
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : pxr.vortac
State Reference	AZ
Altitude	msl single value : 4000
Environment
Flight Conditions	IMC
Weather Elements	Rain Turbulence
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : p50.tracon
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 26 other other vortac
Flight Phase	descent : approach
Route In Use	approach : traffic pattern arrival star : bruser
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 12500 flight time type : 5000
ASRS Report	577253
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	inflight encounter : weather non adherence : far non adherence : published procedure other anomaly other other spatial deviation
Independent Detector	aircraft equipment : gpws other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance flight crew : took evasive action none taken : detected after the fact other
Consequence	faa : reviewed incident with flight crew other
Supplementary
Problem Areas	ATC Human Performance FAA
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error
Situations
ATC Facility	procedure or policy : p50.tracon

Narrative:

While being vectored for an ILS runway 26 in phx from the bruser arrival, we were given a heading of approximately 080 degrees and an altitude of 4000 ft. Conditions were IMC. The downwind vector became unusually long. The frequency was jammed. We were unable to get a word in. We became concerned about our position in regards to known rising terrain to the east. At that moment, we got a 'terrain' alert from GPWS, followed by the 'pull up' message. Although the first officer was flying the aircraft, I executed a full power pull-up. Knowing the terrain was lower to the south, I also turned to 150 degrees. The alert silenced quickly and we broke out on top. Our call to ATC of the event was covered. ATC called us and assigned us heading 150 degrees, which we had previously turned to. We advised ATC of the event and his reply was that we 'should not have gotten one there.' the rest of the approach and landing were uneventful. I believe that ATC 'lost' us in the busy frequency and we were vectored out of class B airspace (4000 ft at 15 DME pxr) and ended up dangerously close to the mountains east of phx. Callback conversation with reporter revealed the following information: the captain reported the incident to his chief pilot. The air carrier ATC procedures specialist contacted the P-50 supervisor and briefed him on the incident. 3 days the supervisor said it was under investigation. The air carrier has heard nothing else. The captain said he grew up and learned to fly in the phx area. He knows the terrain there like the back of his hand.

Original NASA ASRS Text

Title: B737-300 WAS VECTORED BELOW THE PHX CLASS B AIRSPACE AT 4000 FT. THEY GOT A GPWS 'TERRAIN' WARNING.

Narrative: WHILE BEING VECTORED FOR AN ILS RWY 26 IN PHX FROM THE BRUSER ARR, WE WERE GIVEN A HDG OF APPROX 080 DEGS AND AN ALT OF 4000 FT. CONDITIONS WERE IMC. THE DOWNWIND VECTOR BECAME UNUSUALLY LONG. THE FREQ WAS JAMMED. WE WERE UNABLE TO GET A WORD IN. WE BECAME CONCERNED ABOUT OUR POS IN REGARDS TO KNOWN RISING TERRAIN TO THE E. AT THAT MOMENT, WE GOT A 'TERRAIN' ALERT FROM GPWS, FOLLOWED BY THE 'PULL UP' MESSAGE. ALTHOUGH THE FO WAS FLYING THE ACFT, I EXECUTED A FULL PWR PULL-UP. KNOWING THE TERRAIN WAS LOWER TO THE S, I ALSO TURNED TO 150 DEGS. THE ALERT SILENCED QUICKLY AND WE BROKE OUT ON TOP. OUR CALL TO ATC OF THE EVENT WAS COVERED. ATC CALLED US AND ASSIGNED US HDG 150 DEGS, WHICH WE HAD PREVIOUSLY TURNED TO. WE ADVISED ATC OF THE EVENT AND HIS REPLY WAS THAT WE 'SHOULD NOT HAVE GOTTEN ONE THERE.' THE REST OF THE APCH AND LNDG WERE UNEVENTFUL. I BELIEVE THAT ATC 'LOST' US IN THE BUSY FREQ AND WE WERE VECTORED OUT OF CLASS B AIRSPACE (4000 FT AT 15 DME PXR) AND ENDED UP DANGEROUSLY CLOSE TO THE MOUNTAINS E OF PHX. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE CAPT RPTED THE INCIDENT TO HIS CHIEF PLT. THE ACR ATC PROCS SPECIALIST CONTACTED THE P-50 SUPVR AND BRIEFED HIM ON THE INCIDENT. 3 DAYS THE SUPVR SAID IT WAS UNDER INVESTIGATION. THE ACR HAS HEARD NOTHING ELSE. THE CAPT SAID HE GREW UP AND LEARNED TO FLY IN THE PHX AREA. HE KNOWS THE TERRAIN THERE LIKE THE BACK OF HIS HAND.

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.