A DC10 flight crew had to s-turn on final at las to maintain separation with preceding aircraft.

Attributes
ACN	453049
Time
Date	199910
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : las.airport
State Reference	NV
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : las.tower
Operator	common carrier : air carrier
Make Model Name	DC-10 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 25l
Flight Phase	descent : approach
Route In Use	approach : instrument precision
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : las.tower
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 25l
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 15000 flight time type : 5000
ASRS Report	453049
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	other anomaly other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	none taken : anomaly accepted
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

After dhigg on the nootn arrival into las, we were given a vector off course for spacing, then intercepted the runway 25L localizer. Inside tiffy (19.5 DME) descending from 8000 ft to 7000 ft, we were turned off to the left to follow B737 on base leg. Traffic was called in sight. Our clearance was to follow traffic and slow to 170 KTS. B737 overshot the final approach course. Being that I was established on final, I'm now catching the B737. We switched to tower, asked for runway 25R due to the spacing. It was denied. With only 2 - 2 1/2 mi separation and the obvious difference in approach speeds (I was at vref at this time), I opted to s-turn to the left a bit. Control tower wanted to know what I was doing. I was told to advise tower next time. The bottom line is, at no point was I allowed to be stabilized on the approach. I followed all instructions, except for not notifying tower about the s-turn. This airport is the worst. They just do not know how to sequence widebody transport aircraft with other aircraft. This happens all the time. We need help here.

Original NASA ASRS Text

Title: A DC10 FLC HAD TO S-TURN ON FINAL AT LAS TO MAINTAIN SEPARATION WITH PRECEDING ACFT.

Narrative: AFTER DHIGG ON THE NOOTN ARR INTO LAS, WE WERE GIVEN A VECTOR OFF COURSE FOR SPACING, THEN INTERCEPTED THE RWY 25L LOC. INSIDE TIFFY (19.5 DME) DSNDING FROM 8000 FT TO 7000 FT, WE WERE TURNED OFF TO THE L TO FOLLOW B737 ON BASE LEG. TFC WAS CALLED IN SIGHT. OUR CLRNC WAS TO FOLLOW TFC AND SLOW TO 170 KTS. B737 OVERSHOT THE FINAL APCH COURSE. BEING THAT I WAS ESTABLISHED ON FINAL, I'M NOW CATCHING THE B737. WE SWITCHED TO TWR, ASKED FOR RWY 25R DUE TO THE SPACING. IT WAS DENIED. WITH ONLY 2 - 2 1/2 MI SEPARATION AND THE OBVIOUS DIFFERENCE IN APCH SPDS (I WAS AT VREF AT THIS TIME), I OPTED TO S-TURN TO THE L A BIT. CTL TWR WANTED TO KNOW WHAT I WAS DOING. I WAS TOLD TO ADVISE TWR NEXT TIME. THE BOTTOM LINE IS, AT NO POINT WAS I ALLOWED TO BE STABILIZED ON THE APCH. I FOLLOWED ALL INSTRUCTIONS, EXCEPT FOR NOT NOTIFYING TWR ABOUT THE S-TURN. THIS ARPT IS THE WORST. THEY JUST DO NOT KNOW HOW TO SEQUENCE WDB ACFT WITH OTHER ACFT. THIS HAPPENS ALL THE TIME. WE NEED HELP HERE.

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.