A B737-300 first officer reported that they were not cleared for the approach into las by L30.

Attributes
ACN	518140
Time
Date	200107
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : las.airport
State Reference	NV
Altitude	msl bound lower : 4200 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : zzz.tower
Operator	common carrier : air carrier
Make Model Name	B737-300
Flight Phase	descent : approach
Route In Use	approach : visual approach : traffic pattern
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 225 flight time total : 4200 flight time type : 800
ASRS Report	518140
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : published procedure non adherence : far non adherence : clearance non adherence : company policies
Resolutory Action	none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were approaching las from the south/southwest at 6000 ft when the approach controller told us to expect the visual to runway 19L. We were given a northerly heading to cross over the approach end of runway 25L and told to dscnd to 4200 ft. As we were now set up on this 6000 ft base to runway 19L, the captain (flying) started to configure on speed and continued the base/turn to final. During the turn we did receive a 'traffic' alert on the TCASII, but I immediately cleared. The patterns into las were very busy with lots of radio traffic and we were cleared the visual to runway 19L (acknowledged) but I honestly don't remember at exactly what pt on the base/turn to final we were cleared (with the subsequent descent out of 4200 ft). After turning to final, and being told to contact the tower, the captain flew a stabilized approach to an uneventful landing on runway 19L. After engine shutdown at the gate, the operations agent gave the captain a message to call TRACON.

Original NASA ASRS Text

Title: A B737-300 FO RPTED THAT THEY WERE NOT CLRED FOR THE APCH INTO LAS BY L30.

Narrative: WE WERE APCHING LAS FROM THE S/SW AT 6000 FT WHEN THE APCH CTLR TOLD US TO EXPECT THE VISUAL TO RWY 19L. WE WERE GIVEN A NORTHERLY HDG TO CROSS OVER THE APCH END OF RWY 25L AND TOLD TO DSCND TO 4200 FT. AS WE WERE NOW SET UP ON THIS 6000 FT BASE TO RWY 19L, THE CAPT (FLYING) STARTED TO CONFIGURE ON SPD AND CONTINUED THE BASE/TURN TO FINAL. DURING THE TURN WE DID RECEIVE A 'TFC' ALERT ON THE TCASII, BUT I IMMEDIATELY CLRED. THE PATTERNS INTO LAS WERE VERY BUSY WITH LOTS OF RADIO TFC AND WE WERE CLRED THE VISUAL TO RWY 19L (ACKNOWLEDGED) BUT I HONESTLY DON'T REMEMBER AT EXACTLY WHAT PT ON THE BASE/TURN TO FINAL WE WERE CLRED (WITH THE SUBSEQUENT DSCNT OUT OF 4200 FT). AFTER TURNING TO FINAL, AND BEING TOLD TO CONTACT THE TWR, THE CAPT FLEW A STABILIZED APCH TO AN UNEVENTFUL LNDG ON RWY 19L. AFTER ENGINE SHUTDOWN AT THE GATE, THE OPS AGENT GAVE THE CAPT A MESSAGE TO CALL TRACON.

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.