B737 flight crew received a egpws 'terrain' warning during vectors for approach into las.

Attributes
ACN	595139
Time
Date	200310
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : las.vortac
State Reference	NV
Altitude	msl single value : 6000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : l30.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	approach : visual arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 218 flight time total : 20000 flight time type : 12000
ASRS Report	595139
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	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 : exited adverse environment flight crew : took precautionary avoidance action
Consequence	faa : reviewed incident with flight crew other
Supplementary
Problem Areas	Airspace Structure Flight Crew Human Performance ATC Human Performance ATC Facility
Primary Problem	Ambiguous

Narrative:

We were on approach control vectors to a visual for runway 1R at las, assigned heading of 280 degrees at 6000 ft MSL approximately 13 mi southwest of las. Traffic was fairly heavy and we thought approach control might be busy and forgot to turn us toward airport. We had terrain mapping on (I had 5 mi displayed and first officer had 10 mi) and were very aware terrain up to our altitude was closing in. Frequency was busy and I asked first officer to ask for a turn, but couldn't wait for a response from the busy controller, so I began a 30 degree bank turn to the right, when the first officer finally got through to them and approach control said to turn right to 360 degrees. I was about 1/2 way through the turn to that heading and received a 'terrain' or a 'terrain pull up' warning from egpws. I started a smooth, but positive climb. The first officer advised approach we received a warning and were climbing. Approach control told us to turn to 010 degree heading and climb to 7000 ft, which we did. A new controller came on and completed giving us clearance for a visual approach to runway 1R uneventfully. I discussed the event with the las vegas approach control supervisor and several employees at my company over the next 24 hours. I believe traffic congestion contributed to this event, as well as an unusual approach situation (runway 1R is not a very frequent approach), and high terrain in all quadrants from the airport. If we had not been monitoring the terrain on our mapping displays, we would not have been as situationally aware as we were and may have had to do a severe break away maneuver to miss the terrain, if we could have at all. I highly recommend use of the terrain mapping mode in all night and IMC conditions if not at all times to get in the habit of having it available when you don't think about using it in the 'heat of battle' if it is available. If there are WX considerations, 1 pilot still should use terrain and the other WX, if the airplane is so equipped (like the B737-700 is).

Original NASA ASRS Text

Title: B737 FLT CREW RECEIVED A EGPWS 'TERRAIN' WARNING DURING VECTORS FOR APCH INTO LAS.

Narrative: WE WERE ON APCH CTL VECTORS TO A VISUAL FOR RWY 1R AT LAS, ASSIGNED HDG OF 280 DEGS AT 6000 FT MSL APPROX 13 MI SW OF LAS. TFC WAS FAIRLY HEAVY AND WE THOUGHT APCH CTL MIGHT BE BUSY AND FORGOT TO TURN US TOWARD ARPT. WE HAD TERRAIN MAPPING ON (I HAD 5 MI DISPLAYED AND FO HAD 10 MI) AND WERE VERY AWARE TERRAIN UP TO OUR ALT WAS CLOSING IN. FREQ WAS BUSY AND I ASKED FO TO ASK FOR A TURN, BUT COULDN'T WAIT FOR A RESPONSE FROM THE BUSY CTLR, SO I BEGAN A 30 DEG BANK TURN TO THE R, WHEN THE FO FINALLY GOT THROUGH TO THEM AND APCH CTL SAID TO TURN R TO 360 DEGS. I WAS ABOUT 1/2 WAY THROUGH THE TURN TO THAT HDG AND RECEIVED A 'TERRAIN' OR A 'TERRAIN PULL UP' WARNING FROM EGPWS. I STARTED A SMOOTH, BUT POSITIVE CLB. THE FO ADVISED APCH WE RECEIVED A WARNING AND WERE CLBING. APCH CTL TOLD US TO TURN TO 010 DEG HDG AND CLB TO 7000 FT, WHICH WE DID. A NEW CTLR CAME ON AND COMPLETED GIVING US CLRNC FOR A VISUAL APCH TO RWY 1R UNEVENTFULLY. I DISCUSSED THE EVENT WITH THE LAS VEGAS APCH CTL SUPVR AND SEVERAL EMPLOYEES AT MY COMPANY OVER THE NEXT 24 HRS. I BELIEVE TFC CONGESTION CONTRIBUTED TO THIS EVENT, AS WELL AS AN UNUSUAL APCH SIT (RWY 1R IS NOT A VERY FREQUENT APCH), AND HIGH TERRAIN IN ALL QUADRANTS FROM THE ARPT. IF WE HAD NOT BEEN MONITORING THE TERRAIN ON OUR MAPPING DISPLAYS, WE WOULD NOT HAVE BEEN AS SITUATIONALLY AWARE AS WE WERE AND MAY HAVE HAD TO DO A SEVERE BREAK AWAY MANEUVER TO MISS THE TERRAIN, IF WE COULD HAVE AT ALL. I HIGHLY RECOMMEND USE OF THE TERRAIN MAPPING MODE IN ALL NIGHT AND IMC CONDITIONS IF NOT AT ALL TIMES TO GET IN THE HABIT OF HAVING IT AVAILABLE WHEN YOU DON'T THINK ABOUT USING IT IN THE 'HEAT OF BATTLE' IF IT IS AVAILABLE. IF THERE ARE WX CONSIDERATIONS, 1 PLT STILL SHOULD USE TERRAIN AND THE OTHER WX, IF THE AIRPLANE IS SO EQUIPPED (LIKE THE B737-700 IS).

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.