Air carrier widebody transport altitude deviation excursion from clearance altitude in response to w...

Attributes
ACN	126132
Time
Date	198910
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : mod
State Reference	CA
Altitude	msl bound lower : 29500 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zoa
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other descent other
Route In Use	enroute : direct enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 14000 flight time type : 3500
ASRS Report	126132
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	faa : assigned or threatened penalties
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation Operational Deviation

Narrative:

We were inbound to modesto. Just about mono lake, we were given a left turn vector of 30-40 degrees for spacing. After a short time, we were cleared direct to modesto. We were then cleared from 35000 to 31000'. At 31000' we were cleared to cross 15 mi east of modesto at or below 28000', to maintain 24000'. I acknowledged the clearance and we began our descent. At about 29500' and 60 DME east of modesto, ZOA asked our altitude. We replied 29500'. We were told to climb immediately to 31000'. We complied and asked what the problem was. The controller said we had taken a clearance for an air carrier Y flight--no more discussion took place, but I had some questions unanswered: 1) did I take a clearance for another carrier? 2) did the controller perhaps give our flight a clearance meant for the air carrier Y flight? 3) why didn't the controller catch our readback? We all agreed that during descent none of us heard an air carrier Y flight on frequency.

Original NASA ASRS Text

Title: ACR WDB ALT DEVIATION EXCURSION FROM CLRNC ALT IN RESPONSE TO WRONG CALL SIGN.

Narrative: WE WERE INBND TO MODESTO. JUST ABOUT MONO LAKE, WE WERE GIVEN A LEFT TURN VECTOR OF 30-40 DEGS FOR SPACING. AFTER A SHORT TIME, WE WERE CLRED DIRECT TO MODESTO. WE WERE THEN CLRED FROM 35000 TO 31000'. AT 31000' WE WERE CLRED TO CROSS 15 MI E OF MODESTO AT OR BELOW 28000', TO MAINTAIN 24000'. I ACKNOWLEDGED THE CLRNC AND WE BEGAN OUR DSCNT. AT ABOUT 29500' AND 60 DME E OF MODESTO, ZOA ASKED OUR ALT. WE REPLIED 29500'. WE WERE TOLD TO CLB IMMEDIATELY TO 31000'. WE COMPLIED AND ASKED WHAT THE PROB WAS. THE CTLR SAID WE HAD TAKEN A CLRNC FOR AN ACR Y FLT--NO MORE DISCUSSION TOOK PLACE, BUT I HAD SOME QUESTIONS UNANSWERED: 1) DID I TAKE A CLRNC FOR ANOTHER CARRIER? 2) DID THE CTLR PERHAPS GIVE OUR FLT A CLRNC MEANT FOR THE ACR Y FLT? 3) WHY DIDN'T THE CTLR CATCH OUR READBACK? WE ALL AGREED THAT DURING DSCNT NONE OF US HEARD AN ACR Y FLT ON FREQ.

Data retrieved from NASA's ASRS site as of August 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.

Air carrier widebody transport altitude deviation excursion from clearance altitude in response to wrong call sign.