Altitude deviation due to clearance misinterp. 11,000' sounded like 10,000'.

Attributes
ACN	125648
Time
Date	198910
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zid airport : ind
State Reference	IN
Altitude	msl bound lower : 10000 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other descent other
Route In Use	arrival other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : private pilot : flight engineer pilot : atp pilot : commercial pilot : instrument
Experience	flight time last 90 days : 210 flight time total : 11000 flight time type : 4800
ASRS Report	125648
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	faa : reviewed incident with flight crew Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	Operational Deviation Pilot Deviation other

Narrative:

Flight was given a crossing restriction by ZID on descent into ind. The clearance was read back by another aircraft. The controller then issued a crossing restriction to said aircraft with his proper call sign and was read back by said aircraft. Another clearance was given to our flight with our readback. Descent was made to 10,000 30 away from ind VOR at 210 KTS. ATC questioned our altitude at 10,000 with his said instructions being at 11,000. His check with ind approach required no altitude change and no action was required. Upon landing I called ZID and spoke with the supervisor on duty. His response was favorable with no action by him required.

Original NASA ASRS Text

Title: ALT DEVIATION DUE TO CLRNC MISINTERP. 11,000' SOUNDED LIKE 10,000'.

Narrative: FLT WAS GIVEN A XING RESTRICTION BY ZID ON DSCNT INTO IND. THE CLRNC WAS READ BACK BY ANOTHER ACFT. THE CTLR THEN ISSUED A XING RESTRICTION TO SAID ACFT WITH HIS PROPER CALL SIGN AND WAS READ BACK BY SAID ACFT. ANOTHER CLRNC WAS GIVEN TO OUR FLT WITH OUR READBACK. DSCNT WAS MADE TO 10,000 30 AWAY FROM IND VOR AT 210 KTS. ATC QUESTIONED OUR ALT AT 10,000 WITH HIS SAID INSTRUCTIONS BEING AT 11,000. HIS CHECK WITH IND APCH REQUIRED NO ALT CHANGE AND NO ACTION WAS REQUIRED. UPON LNDG I CALLED ZID AND SPOKE WITH THE SUPVR ON DUTY. HIS RESPONSE WAS FAVORABLE WITH NO ACTION BY HIM REQUIRED.

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.