ZLA radar controller may have misspoken and issued an incorrect crossing altitude to a B737 crew.

Attributes
ACN	582370
Time
Date	200305
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	intersection : amigo
State Reference	CA
Altitude	msl single value : 15000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla.artcc
Operator	common carrier : air carrier
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach descent : intermediate altitude
Route In Use	arrival star : paradise
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zla.artcc
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : instrument pilot : multi engine pilot : atp
Experience	flight time last 90 days : 200 flight time total : 13000 flight time type : 1200
ASRS Report	582370
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time total : 3000
ASRS Report	582496
Events
Anomaly	conflict : airborne less severe non adherence : published procedure other anomaly other
Independent Detector	atc equipment other atc equipment : radar mode c aircraft equipment : tcas other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance none taken : detected after the fact
Miss Distance	horizontal : 30000 vertical : 0
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

During descent on the PARADISE4 arrival into lax, air carrier X was given the crossing restr 'cross amigo at 15000 ft.' the first officer read back 'cross amigo at 15000 ft.' approximately 2 mins after we had leveled at 15000 ft, ZLA asked us what our altitude was. The first officer said 'our clearance was to cross amigo at 15000 ft,' and we were level at 15000 ft. ZLA said there was an air carrier Y jet at 15000 ft at our 10 O'clock position. ZLA gave air carrier Y a 20 degree turn for traffic separation. We did have a TA on the TCASII, but no RA. Traffic was estimated at our altitude at no closer than 5 mi. I believe the controller gave us an altitude assignment of 15000 ft in error.

Original NASA ASRS Text

Title: ZLA RADAR CTLR MAY HAVE MISSPOKEN AND ISSUED AN INCORRECT XING ALT TO A B737 CREW.

Narrative: DURING DSCNT ON THE PARADISE4 ARR INTO LAX, ACR X WAS GIVEN THE XING RESTR 'CROSS AMIGO AT 15000 FT.' THE FO READ BACK 'CROSS AMIGO AT 15000 FT.' APPROX 2 MINS AFTER WE HAD LEVELED AT 15000 FT, ZLA ASKED US WHAT OUR ALT WAS. THE FO SAID 'OUR CLRNC WAS TO CROSS AMIGO AT 15000 FT,' AND WE WERE LEVEL AT 15000 FT. ZLA SAID THERE WAS AN ACR Y JET AT 15000 FT AT OUR 10 O'CLOCK POS. ZLA GAVE ACR Y A 20 DEG TURN FOR TFC SEPARATION. WE DID HAVE A TA ON THE TCASII, BUT NO RA. TFC WAS ESTIMATED AT OUR ALT AT NO CLOSER THAN 5 MI. I BELIEVE THE CTLR GAVE US AN ALT ASSIGNMENT OF 15000 FT IN ERROR.

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.