A B757-200 flight crew attempts to sort out some call sign confusion on the part of the ARTCC radar ...

Attributes
ACN	460445
Time
Date	200001
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : trm.vortac
State Reference	CA
Altitude	msl bound lower : 24000 msl bound upper : 29000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla.artcc
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Navigation In Use	other other vortac
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zla.artcc
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Navigation In Use	other other vortac
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : atp pilot : commercial pilot : flight engineer pilot : instrument
Experience	flight time last 90 days : 250 flight time total : 7500 flight time type : 2500
ASRS Report	460445
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : separated traffic controller : issued advisory controller : issued new clearance
Consequence	faa : investigated faa : reviewed incident with flight crew
Supplementary
Problem Areas	Environmental Factor Flight Crew Human Performance ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Deviation Pilot Deviation

Narrative:

The problem I believed occurred due to a misunderstanding of controller instructions and not listening to the pilot readback. Our aircraft was following another turbojet (A320?). I am used to paying attention to all radio calls that use our company call sign 'xyz' and then listening for my particular number. In this case, I think the controller used another company call sign followed by my flight number. 'Xyy 1234, climb and maintain FL290.' since I didn't hear 'xyz' there was a long pause and I called the controller and asked 'ZLA, was that for xyz 1234?' his response was 'roger xyy 1234, climb and maintain FL290' again a pause (no other aircraft responding, so I thought he had confused 'xyy' with 'xyz' so I replied 'xyz 1234 climbing FL290' pause, no response from other aircraft. We then began a climb to FL290. At around FL248 the controller gave a 'turn heading 100 for traffic' then a few seconds later said 'xyz 1234 you were cleared to FL240, maintain FL240.' I replied that we had checked twice about the climb and we were cleared to FL290. The controller gave us a phone number to call later. 3 hours later with ZHU (132.4) we were told 'situation is resolved at ZLA, you don't have to call back to ZLA.' I think the controller intended to climb an xyy flight, but used our flight number. I heard the number, but not the first part since he didn't use 'xyz.' when I called back to confirm, he thought the xyy flight was talking to him, even though I was using my xyz call sign. He then cleared what he thought was his xyy flight, but again used our flight call sign. Again I read back xyz cleared to FL290. He didn't correct the error when I twice called to inquire if the climb was for xyz 1234. In all cases, there was a long pause, so if there was an xyy 1234, they could have answered. This must have set off an alarm since the plane we were following was around 9 mi and we matched altitudes for a short time. Solution: we shouldn't have started our climb until we heard both xyz and the correct flight number. The controller should have listened to our readbacks using the xyz call sign.

Original NASA ASRS Text

Title: A B757-200 FLC ATTEMPTS TO SORT OUT SOME CALL SIGN CONFUSION ON THE PART OF THE ARTCC RADAR CTLR AT ZLA WITHOUT TOO MUCH SUCCESS. FLT LEAVES ASSIGNED ALT AGAINST ZLA'S DESIRES OR KNOWLEDGE.

Narrative: THE PROB I BELIEVED OCCURRED DUE TO A MISUNDERSTANDING OF CTLR INSTRUCTIONS AND NOT LISTENING TO THE PLT READBACK. OUR ACFT WAS FOLLOWING ANOTHER TURBOJET (A320?). I AM USED TO PAYING ATTN TO ALL RADIO CALLS THAT USE OUR COMPANY CALL SIGN 'XYZ' AND THEN LISTENING FOR MY PARTICULAR NUMBER. IN THIS CASE, I THINK THE CTLR USED ANOTHER COMPANY CALL SIGN FOLLOWED BY MY FLT NUMBER. 'XYY 1234, CLB AND MAINTAIN FL290.' SINCE I DIDN'T HEAR 'XYZ' THERE WAS A LONG PAUSE AND I CALLED THE CTLR AND ASKED 'ZLA, WAS THAT FOR XYZ 1234?' HIS RESPONSE WAS 'ROGER XYY 1234, CLB AND MAINTAIN FL290' AGAIN A PAUSE (NO OTHER ACFT RESPONDING, SO I THOUGHT HE HAD CONFUSED 'XYY' WITH 'XYZ' SO I REPLIED 'XYZ 1234 CLBING FL290' PAUSE, NO RESPONSE FROM OTHER ACFT. WE THEN BEGAN A CLB TO FL290. AT AROUND FL248 THE CTLR GAVE A 'TURN HDG 100 FOR TFC' THEN A FEW SECONDS LATER SAID 'XYZ 1234 YOU WERE CLRED TO FL240, MAINTAIN FL240.' I REPLIED THAT WE HAD CHKED TWICE ABOUT THE CLB AND WE WERE CLRED TO FL290. THE CTLR GAVE US A PHONE NUMBER TO CALL LATER. 3 HRS LATER WITH ZHU (132.4) WE WERE TOLD 'SIT IS RESOLVED AT ZLA, YOU DON'T HAVE TO CALL BACK TO ZLA.' I THINK THE CTLR INTENDED TO CLB AN XYY FLT, BUT USED OUR FLT NUMBER. I HEARD THE NUMBER, BUT NOT THE FIRST PART SINCE HE DIDN'T USE 'XYZ.' WHEN I CALLED BACK TO CONFIRM, HE THOUGHT THE XYY FLT WAS TALKING TO HIM, EVEN THOUGH I WAS USING MY XYZ CALL SIGN. HE THEN CLRED WHAT HE THOUGHT WAS HIS XYY FLT, BUT AGAIN USED OUR FLT CALL SIGN. AGAIN I READ BACK XYZ CLRED TO FL290. HE DIDN'T CORRECT THE ERROR WHEN I TWICE CALLED TO INQUIRE IF THE CLB WAS FOR XYZ 1234. IN ALL CASES, THERE WAS A LONG PAUSE, SO IF THERE WAS AN XYY 1234, THEY COULD HAVE ANSWERED. THIS MUST HAVE SET OFF AN ALARM SINCE THE PLANE WE WERE FOLLOWING WAS AROUND 9 MI AND WE MATCHED ALTS FOR A SHORT TIME. SOLUTION: WE SHOULDN'T HAVE STARTED OUR CLB UNTIL WE HEARD BOTH XYZ AND THE CORRECT FLT NUMBER. THE CTLR SHOULD HAVE LISTENED TO OUR READBACKS USING THE XYZ CALL SIGN.

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.

A B757-200 flight crew attempts to sort out some call sign confusion on the part of the ARTCC radar controller at ZLA without too much success. Flight leaves assigned altitude against ZLA's desires or knowledge.