Air carrier accepted clearance for another air carrier and began climb resulting in less than standa...

Attributes
ACN	159475
Time
Date	199010
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : spa
State Reference	SC
Altitude	msl bound lower : 27000 msl bound upper : 27300
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 135 flight time total : 14500 flight time type : 3000
ASRS Report	159475
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 40 flight time total : 6000 flight time type : 3000
ASRS Report	159474
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : required legal separation non adherence : clearance other anomaly other
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	other
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 18000 vertical : 700
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We requested to climb from FL270 to FL290. We heard clearance to FL290 and read it back to center, and started to climb. At FL273 the controller said 'air carrier X maintain FL270.' we quickly descended to FL270. He also said we had traffic 12 O'clock, 5 mi at FL280. I tried to inquire about the situation but controller was too busy to get back to us and soon thereafter handed us to another controller. After landing in baltimore, I called the atl center supervisor and he said we answered a clearance for another company flight with similar call sign who had requested clearance to FL290. Controller did not catch my call sign (apparently) on my readback. The other company flight told controller he thought someone else answered the clearance to FL290. We did not recall hearing the other company flight say this. This seems to be the time when the controller told us to descend back to FL270. The radio traffic was extremely heavy at this time, also there possibly could have been precipitation static on our radios which might have led us to think the clearance to climb was for us.

Original NASA ASRS Text

Title: ACR ACCEPTED CLRNC FOR ANOTHER ACR AND BEGAN CLIMB RESULTING IN LESS THAN STANDARD SEPARATION.

Narrative: WE REQUESTED TO CLB FROM FL270 TO FL290. WE HEARD CLRNC TO FL290 AND READ IT BACK TO CTR, AND STARTED TO CLB. AT FL273 THE CTLR SAID 'ACR X MAINTAIN FL270.' WE QUICKLY DSNDED TO FL270. HE ALSO SAID WE HAD TFC 12 O'CLOCK, 5 MI AT FL280. I TRIED TO INQUIRE ABOUT THE SITUATION BUT CTLR WAS TOO BUSY TO GET BACK TO US AND SOON THEREAFTER HANDED US TO ANOTHER CTLR. AFTER LNDG IN BALTIMORE, I CALLED THE ATL CTR SUPVR AND HE SAID WE ANSWERED A CLRNC FOR ANOTHER COMPANY FLT WITH SIMILAR CALL SIGN WHO HAD REQUESTED CLRNC TO FL290. CTLR DID NOT CATCH MY CALL SIGN (APPARENTLY) ON MY READBACK. THE OTHER COMPANY FLT TOLD CTLR HE THOUGHT SOMEONE ELSE ANSWERED THE CLRNC TO FL290. WE DID NOT RECALL HEARING THE OTHER COMPANY FLT SAY THIS. THIS SEEMS TO BE THE TIME WHEN THE CTLR TOLD US TO DSND BACK TO FL270. THE RADIO TFC WAS EXTREMELY HVY AT THIS TIME, ALSO THERE POSSIBLY COULD HAVE BEEN PRECIP STATIC ON OUR RADIOS WHICH MIGHT HAVE LED US TO THINK THE CLRNC TO CLB WAS FOR US.

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.

Air carrier accepted clearance for another air carrier and began climb resulting in less than standard separation.