Similar call signs cause confusion at iah, tx.

Attributes
ACN	466031
Time
Date	200003
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : iah.airport
State Reference	TX
Altitude	agl bound lower : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : iah.tower
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : takeoff climbout : initial
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : iah.tower
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	ground : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 12000 flight time type : 500
ASRS Report	466031
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Problem Areas	Company ATC Human Performance Flight Crew Human Performance
Primary Problem	ATC Human Performance

Narrative:

Our flight number was air carrier X. The tower gave the clearance for air carrier Y to taxi up to and hold short of runway 15L. The first officer replied air carrier X up to and hold short of runway 15L. I did not challenge the ATC instruction, feeling certain tower had simply made an error. We received a clearance to taxi into position and hold as air carrier X. I at that point felt comfortable that we were in the correct sequence. When takeoff clearance was received I thought I heard air carrier X cleared for takeoff. It was not until we were told 'air carrier Y contact departure' I became wary of our initial takeoff clearance. Our initial contact with houston departure we called 'air carrier X.' departure responded 'air carrier Y radar contact.' I asked the first officer to recall departure and emphasize air carrier X not Y. Departure simply replied 'roger air carrier Y, radar contact.' it wasn't until I heard air carrier Y check onto ZHU a few mins later that I felt certain an error had occurred. I spoke privately to the captain of air carrier Y and he said he was not even in a position to taxi up to and hold short when we were given our initial clearance, and that tower had not mentioned any sequencing problems to him. ATC never mentioned any feeling that we had received an improper takeoff clearance either. I feel that I should have challenged sooner and received a confirmation of our flight number and sequencing.

Original NASA ASRS Text

Title: SIMILAR CALL SIGNS CAUSE CONFUSION AT IAH, TX.

Narrative: OUR FLT NUMBER WAS ACR X. THE TWR GAVE THE CLRNC FOR ACR Y TO TAXI UP TO AND HOLD SHORT OF RWY 15L. THE FO REPLIED ACR X UP TO AND HOLD SHORT OF RWY 15L. I DID NOT CHALLENGE THE ATC INSTRUCTION, FEELING CERTAIN TWR HAD SIMPLY MADE AN ERROR. WE RECEIVED A CLRNC TO TAXI INTO POS AND HOLD AS ACR X. I AT THAT POINT FELT COMFORTABLE THAT WE WERE IN THE CORRECT SEQUENCE. WHEN TKOF CLRNC WAS RECEIVED I THOUGHT I HEARD ACR X CLRED FOR TKOF. IT WAS NOT UNTIL WE WERE TOLD 'ACR Y CONTACT DEP' I BECAME WARY OF OUR INITIAL TKOF CLRNC. OUR INITIAL CONTACT WITH HOUSTON DEP WE CALLED 'ACR X.' DEP RESPONDED 'ACR Y RADAR CONTACT.' I ASKED THE FO TO RECALL DEP AND EMPHASIZE ACR X NOT Y. DEP SIMPLY REPLIED 'ROGER ACR Y, RADAR CONTACT.' IT WASN'T UNTIL I HEARD ACR Y CHK ONTO ZHU A FEW MINS LATER THAT I FELT CERTAIN AN ERROR HAD OCCURRED. I SPOKE PRIVATELY TO THE CAPT OF ACR Y AND HE SAID HE WAS NOT EVEN IN A POS TO TAXI UP TO AND HOLD SHORT WHEN WE WERE GIVEN OUR INITIAL CLRNC, AND THAT TWR HAD NOT MENTIONED ANY SEQUENCING PROBS TO HIM. ATC NEVER MENTIONED ANY FEELING THAT WE HAD RECEIVED AN IMPROPER TKOF CLRNC EITHER. I FEEL THAT I SHOULD HAVE CHALLENGED SOONER AND RECEIVED A CONFIRMATION OF OUR FLT NUMBER AND SEQUENCING.

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.