Air carrier responds and complies with clearance but finds 2 acrs with same flight #south.

Attributes
ACN	164811
Time
Date	199012
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : buj
State Reference	TX
Altitude	msl bound lower : 34500 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw tower : chs
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : cfi pilot : atp pilot : commercial
Experience	flight time last 90 days : 200 flight time total : 14000 flight time type : 840
ASRS Report	164811
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

Copilot was flying aircraft in cruise at FL350. I left ATC frequency to listen to dfw ATIS. I returned to ATC frequency and I saw copilot reach up and dial in FL270 in MCP window. I finished writing down the ATIS as the copilot eased the aircraft out of FL350 on autoplt/autoflt. The copilot told me that we had been cleared to FL270. I asked him if he had checked us out of altitude. He said that he had. Descended through FL345. ATC called and said to climb to FL350! Aircraft was climbed back to FL350. I asked the copilot again about the clearance and he replied that we had been cleared to FL270, and that he had checked us out of FL350 and that the ATC controller had acknowledged that. I then heard on the radio another aircraft from a different aircraft with the same flight # call center. Center answered him back, using just the flight # and not the airline name. I immediately told the controller that there were 2 flts with the same #. He then began calling flts using the full call signs (company and flight #). When will this ongoing problem get the attention it deserves--when we have an accident??!!

Original NASA ASRS Text

Title: ACR RESPONDS AND COMPLIES WITH CLRNC BUT FINDS 2 ACRS WITH SAME FLT #S.

Narrative: COPLT WAS FLYING ACFT IN CRUISE AT FL350. I LEFT ATC FREQ TO LISTEN TO DFW ATIS. I RETURNED TO ATC FREQ AND I SAW COPLT REACH UP AND DIAL IN FL270 IN MCP WINDOW. I FINISHED WRITING DOWN THE ATIS AS THE COPLT EASED THE ACFT OUT OF FL350 ON AUTOPLT/AUTOFLT. THE COPLT TOLD ME THAT WE HAD BEEN CLRED TO FL270. I ASKED HIM IF HE HAD CHKED US OUT OF ALT. HE SAID THAT HE HAD. DSNDED THROUGH FL345. ATC CALLED AND SAID TO CLB TO FL350! ACFT WAS CLBED BACK TO FL350. I ASKED THE COPLT AGAIN ABOUT THE CLRNC AND HE REPLIED THAT WE HAD BEEN CLRED TO FL270, AND THAT HE HAD CHKED US OUT OF FL350 AND THAT THE ATC CTLR HAD ACKNOWLEDGED THAT. I THEN HEARD ON THE RADIO ANOTHER ACFT FROM A DIFFERENT ACFT WITH THE SAME FLT # CALL CENTER. CENTER ANSWERED HIM BACK, USING JUST THE FLT # AND NOT THE AIRLINE NAME. I IMMEDIATELY TOLD THE CTLR THAT THERE WERE 2 FLTS WITH THE SAME #. HE THEN BEGAN CALLING FLTS USING THE FULL CALL SIGNS (COMPANY AND FLT #). WHEN WILL THIS ONGOING PROB GET THE ATTN IT DESERVES--WHEN WE HAVE AN ACCIDENT??!!

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.