Air carrier reads back another aircraft's clearance and ATC catches it.

Attributes
ACN	452390
Time
Date	199910
Day	Thu
Local Time Of Day	1201 To 1800
Place
State Reference	TX
Altitude	msl single value : 28000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw.artcc
Operator	common carrier : air carrier
Make Model Name	B727-200
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : multi engine
ASRS Report	452390
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : atp
ASRS Report	452491
Events
Anomaly	other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

Aircraft on same frequency. Received and read back clearance to descend from FL280 to FL240. ATC cleared other flight to FL240. ATC requested we confirm our altitude. They then reclred us to FL240.

Original NASA ASRS Text

Title: ACR READS BACK ANOTHER ACFT'S CLRNC AND ATC CATCHES IT.

Narrative: ACFT ON SAME FREQ. RECEIVED AND READ BACK CLRNC TO DSND FROM FL280 TO FL240. ATC CLRED OTHER FLT TO FL240. ATC REQUESTED WE CONFIRM OUR ALT. THEY THEN RECLRED US TO FL240.

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.