Flight crew responds to clearance intended for another aircraft approaching ind.

Attributes
ACN	442170
Time
Date	199907
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : vhp.vor
State Reference	IN
Altitude	msl bound lower : 6500 msl bound upper : 7000
Environment
Flight Conditions	Mixed
Weather Elements	Rain Thunderstorm
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ind.tracon
Operator	common carrier : air carrier
Make Model Name	B727-200
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 11000 flight time type : 3600
ASRS Report	442170
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	atc equipment other atc equipment : radar other controllera
Resolutory Action	controller : issued new clearance flight crew : returned to assigned altitude
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While level at 7000 ft, we thought we received clearance to 6000 ft. We read back the altitude leaving and assigned and aircraft call sign. At approximately 6500 ft, controller called and said to maintain 7000 ft. We replied that we were at 6500 ft and returning to 7000 ft. We believe that the original descent had been issued to another aircraft with a similar call sign that was being worked on another frequency. High controller workload and multiple frequencys increase the likelihood of miscoms.

Original NASA ASRS Text

Title: FLC RESPONDS TO CLRNC INTENDED FOR ANOTHER ACFT APCHING IND.

Narrative: WHILE LEVEL AT 7000 FT, WE THOUGHT WE RECEIVED CLRNC TO 6000 FT. WE READ BACK THE ALT LEAVING AND ASSIGNED AND ACFT CALL SIGN. AT APPROX 6500 FT, CTLR CALLED AND SAID TO MAINTAIN 7000 FT. WE REPLIED THAT WE WERE AT 6500 FT AND RETURNING TO 7000 FT. WE BELIEVE THAT THE ORIGINAL DSCNT HAD BEEN ISSUED TO ANOTHER ACFT WITH A SIMILAR CALL SIGN THAT WAS BEING WORKED ON ANOTHER FREQ. HIGH CTLR WORKLOAD AND MULTIPLE FREQS INCREASE THE LIKELIHOOD OF MISCOMS.

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.