Air carrier large transport altitude deviation excursion from clearance altitude in response to wron...

Attributes
ACN	95030
Time
Date	198809
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : drk
State Reference	AZ
Altitude	msl bound lower : 34500 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zab
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 200 flight time total : 4500 flight time type : 1000
ASRS Report	95030
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 flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Flight from tucson to las vegas. In cruise flight at FL350. I was the PF and was on autoplt. Our flight was company xee. We heard ATC give an instruction for company eex to cross 45 NM north of drake at FL330. We (captain and myself) had not heard any previous instructions to a company eex and felt ATC may have meant us (company xee). The captain called center and said 'understand company ee to cross 45 north of drake at FL330?' ATC answered affirmative. I began an autoplt descent (approximately 1200 FPM) to meet the restriction. Captain and I then heard ATC talking to company eex. I asked the captain to verify our clearance to descend and began a climb from approximately 34500' back to FL350. The captain got a hold of ATC and confirmed our altitude was FL350 and that the descent clearance was for company eex. Problem: ATC had issued descent to company eex not us company ee, but made a mistake not catching the problem when we read back the clearance. Solution: always advise crews of similar call signs and numbers. Be careful of clrncs issued to similar sounding call sign aircraft.

Original NASA ASRS Text

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

Narrative: FLT FROM TUCSON TO LAS VEGAS. IN CRUISE FLT AT FL350. I WAS THE PF AND WAS ON AUTOPLT. OUR FLT WAS COMPANY XEE. WE HEARD ATC GIVE AN INSTRUCTION FOR COMPANY EEX TO CROSS 45 NM N OF DRAKE AT FL330. WE (CAPT AND MYSELF) HAD NOT HEARD ANY PREVIOUS INSTRUCTIONS TO A COMPANY EEX AND FELT ATC MAY HAVE MEANT US (COMPANY XEE). THE CAPT CALLED CENTER AND SAID 'UNDERSTAND COMPANY EE TO CROSS 45 N OF DRAKE AT FL330?' ATC ANSWERED AFFIRMATIVE. I BEGAN AN AUTOPLT DSCNT (APPROX 1200 FPM) TO MEET THE RESTRICTION. CAPT AND I THEN HEARD ATC TALKING TO COMPANY EEX. I ASKED THE CAPT TO VERIFY OUR CLRNC TO DSND AND BEGAN A CLB FROM APPROX 34500' BACK TO FL350. THE CAPT GOT A HOLD OF ATC AND CONFIRMED OUR ALT WAS FL350 AND THAT THE DSCNT CLRNC WAS FOR COMPANY EEX. PROB: ATC HAD ISSUED DSCNT TO COMPANY EEX NOT US COMPANY EE, BUT MADE A MISTAKE NOT CATCHING THE PROB WHEN WE READ BACK THE CLRNC. SOLUTION: ALWAYS ADVISE CREWS OF SIMILAR CALL SIGNS AND NUMBERS. BE CAREFUL OF CLRNCS ISSUED TO SIMILAR SOUNDING CALL SIGN ACFT.

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 large transport altitude deviation excursion from clearance altitude in response to wrong call sign.