Air carrier took clearance intended for another aircraft resulting in less than standard separation.

Attributes
ACN	114512
Time
Date	198906
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pxv
State Reference	IN
Altitude	msl bound lower : 15800 msl bound upper : 17000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : sjc
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	cruise other
Route In Use	enroute airway : zid
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
ASRS Report	114512
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller military : 4 controller radar : 27
ASRS Report	114511
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation other anomaly other
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	none taken : detected after the fact
Consequence	Other
Miss Distance	horizontal : 18000 vertical : 200
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Light transport X level at 16,000 was inbound to evv. Air carrier Y was en route to evv at FL220 cleared to descend to 17,000. Cleared light transport X to descend to 11,000 but air carrier Y read back and took the clearance to 11,000 instead. By the time I realized what had happened it was too late. I suggest that pilots pay more attention when WX if VFR. We don't have this problem when IFR or real busy.

Original NASA ASRS Text

Title: ACR TOOK CLRNC INTENDED FOR ANOTHER ACFT RESULTING IN LESS THAN STANDARD SEPARATION.

Narrative: LTT X LEVEL AT 16,000 WAS INBND TO EVV. ACR Y WAS ENRTE TO EVV AT FL220 CLRED TO DSND TO 17,000. CLRED LTT X TO DSND TO 11,000 BUT ACR Y READ BACK AND TOOK THE CLRNC TO 11,000 INSTEAD. BY THE TIME I REALIZED WHAT HAD HAPPENED IT WAS TOO LATE. I SUGGEST THAT PLTS PAY MORE ATTN WHEN WX IF VFR. WE DON'T HAVE THIS PROBLEM WHEN IFR OR REAL BUSY.

Data retrieved from NASA's ASRS site as of August 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.