Readback hearback problem leads to altitude and track deviation.

Attributes
ACN	306580
Time
Date	199506
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ord
State Reference	IL
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ord
Operator	common carrier : air carrier
Make Model Name	B767-200
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other descent : approach
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	306580
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Mis-heard heading from approach control. During approach to runway 9L at ord, controller gave us heading and altitude change. We apparently mis- heard controller and turned to the incorrect heading and started to descend. I believe we read back what we thought the controller said and he mis-heard us. When the controller saw that we were not doing what he had intended, he gave us a climb and a vector to runway 9R. Remainder of flight completed without incident. We received no TCASII alerts during this incident. Controller did an excellent job recognizing our error and vectoring us back for approach to runway 9R.

Original NASA ASRS Text

Title: READBACK HEARBACK PROB LEADS TO ALT AND TRACK DEV.

Narrative: MIS-HEARD HDG FROM APCH CTL. DURING APCH TO RWY 9L AT ORD, CTLR GAVE US HDG AND ALT CHANGE. WE APPARENTLY MIS- HEARD CTLR AND TURNED TO THE INCORRECT HDG AND STARTED TO DSND. I BELIEVE WE READ BACK WHAT WE THOUGHT THE CTLR SAID AND HE MIS-HEARD US. WHEN THE CTLR SAW THAT WE WERE NOT DOING WHAT HE HAD INTENDED, HE GAVE US A CLB AND A VECTOR TO RWY 9R. REMAINDER OF FLT COMPLETED WITHOUT INCIDENT. WE RECEIVED NO TCASII ALERTS DURING THIS INCIDENT. CTLR DID AN EXCELLENT JOB RECOGNIZING OUR ERROR AND VECTORING US BACK FOR APCH TO RWY 9R.

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.