Variance in ATC instructions intended and perceived.

Attributes
ACN	128542
Time
Date	198911
Day	Fri
Local Time Of Day	0001 To 0600
Place
Locale Reference	atc facility : iiu airport : lou
State Reference	KY
Altitude	msl bound lower : 10000 msl bound upper : 13000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : lou
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : commercial pilot : instrument
Experience	flight time last 90 days : 220 flight time total : 3800 flight time type : 350
ASRS Report	128542
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	Pilot Deviation other

Narrative:

Takeoff occurred on the south runway (17 or 18). Light to moderate turbulence encountered through 5000' MSL. The copilot (myself) was flying. First vector after departing the runway was to turn left and climb. Due to the turbulence, I do not recall the heading or altitude assigned. The captain was handling the radios and read back the altitude and heading clearance. I reached down and set the heading bug, thought I do not remember the heading. The captain set the altitude bug to 13000'. We were then passed to another controller within 15-20 seconds of the clearance in question. Upon checking in with the new controller, the captain distinctly repeated climbing to 13000' twice. We were then turned to a heading of 030 degrees and then again to 360 degrees. The controller then queried our altitude (12700'), immediately requested a descent to 12000, and then 10000' with a turn to 270 degrees. Factors affecting readback to clearance: 1) high workload due to turbulence, 2) poor cockpit position of altitude bug (captain reaches over to copilot side to set bug), 3) failure of cockpit to verify initial clearance.

Original NASA ASRS Text

Title: VARIANCE IN ATC INSTRUCTIONS INTENDED AND PERCEIVED.

Narrative: TKOF OCCURRED ON THE S RWY (17 OR 18). LIGHT TO MODERATE TURB ENCOUNTERED THROUGH 5000' MSL. THE COPLT (MYSELF) WAS FLYING. FIRST VECTOR AFTER DEPARTING THE RWY WAS TO TURN LEFT AND CLB. DUE TO THE TURB, I DO NOT RECALL THE HDG OR ALT ASSIGNED. THE CAPT WAS HANDLING THE RADIOS AND READ BACK THE ALT AND HDG CLRNC. I REACHED DOWN AND SET THE HDG BUG, THOUGHT I DO NOT REMEMBER THE HDG. THE CAPT SET THE ALT BUG TO 13000'. WE WERE THEN PASSED TO ANOTHER CTLR WITHIN 15-20 SECS OF THE CLRNC IN QUESTION. UPON CHKING IN WITH THE NEW CTLR, THE CAPT DISTINCTLY REPEATED CLBING TO 13000' TWICE. WE WERE THEN TURNED TO A HDG OF 030 DEGS AND THEN AGAIN TO 360 DEGS. THE CTLR THEN QUERIED OUR ALT (12700'), IMMEDIATELY REQUESTED A DSCNT TO 12000, AND THEN 10000' WITH A TURN TO 270 DEGS. FACTORS AFFECTING READBACK TO CLRNC: 1) HIGH WORKLOAD DUE TO TURB, 2) POOR COCKPIT POS OF ALT BUG (CAPT REACHES OVER TO COPLT SIDE TO SET BUG), 3) FAILURE OF COCKPIT TO VERIFY INITIAL CLRNC.

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.