Air carrier medium large transport track deviation after departure from mdw.

Attributes
ACN	184852
Time
Date	199107
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mdw
State Reference	IL
Altitude	msl bound lower : 2000 msl bound upper : 2000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ord tower : mdw
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : takeoff climbout : intermediate altitude
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : atp
Experience	flight time last 90 days : 150 flight time total : 7000 flight time type : 5000
ASRS Report	184852
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	non adherence : clearance other anomaly other other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	other

Narrative:

Mdw tower cleared our flight for immediate takeoff from runway 04 and issued departure instructions of 'turn left 260 degree.' our destination was det and I realized the departure instructions were probably incorrect for our direction of flight. But because of landing traffic to runway 04 being close in, we took off and decided to rectify the departure airborne. We switched to chicago departure and checked in with 'left to 260 degree but we're headed for detroit.' departure said, 'there's something wrong here, keep the turn coming.' when passing through approximately 120 degree departure asked what we were doing and what heading we were passing through? After our reply he said that when he said 'keep the turn coming' we hadn't reached 260 degree yet and he meant keep turning to 260 degree. We were then given a right turn back to the north. I could have queried tower as to the departure instructions but there wasn't time prior to takeoff. Possibly immediately after takeoff but the cockpit is rather busy then. I could have further clarified the turn with departure but at the time the instructions seemed pretty clear, especially since a continued turn would put us on course. From or standpoint there was not a visible conflict, but I have no idea what the controller had on his scope.

Original NASA ASRS Text

Title: ACR MLG TRACK DEV AFTER DEP FROM MDW.

Narrative: MDW TWR CLRED OUR FLT FOR IMMEDIATE TKOF FROM RWY 04 AND ISSUED DEP INSTRUCTIONS OF 'TURN L 260 DEG.' OUR DEST WAS DET AND I REALIZED THE DEP INSTRUCTIONS WERE PROBABLY INCORRECT FOR OUR DIRECTION OF FLT. BUT BECAUSE OF LNDG TFC TO RWY 04 BEING CLOSE IN, WE TOOK OFF AND DECIDED TO RECTIFY THE DEP AIRBORNE. WE SWITCHED TO CHICAGO DEP AND CHKED IN WITH 'L TO 260 DEG BUT WE'RE HEADED FOR DETROIT.' DEP SAID, 'THERE'S SOMETHING WRONG HERE, KEEP THE TURN COMING.' WHEN PASSING THROUGH APPROX 120 DEG DEP ASKED WHAT WE WERE DOING AND WHAT HDG WE WERE PASSING THROUGH? AFTER OUR REPLY HE SAID THAT WHEN HE SAID 'KEEP THE TURN COMING' WE HADN'T REACHED 260 DEG YET AND HE MEANT KEEP TURNING TO 260 DEG. WE WERE THEN GIVEN A R TURN BACK TO THE N. I COULD HAVE QUERIED TWR AS TO THE DEP INSTRUCTIONS BUT THERE WASN'T TIME PRIOR TO TKOF. POSSIBLY IMMEDIATELY AFTER TKOF BUT THE COCKPIT IS RATHER BUSY THEN. I COULD HAVE FURTHER CLARIFIED THE TURN WITH DEP BUT AT THE TIME THE INSTRUCTIONS SEEMED PRETTY CLR, ESPECIALLY SINCE A CONTINUED TURN WOULD PUT US ON COURSE. FROM OR STANDPOINT THERE WAS NOT A VISIBLE CONFLICT, BUT I HAVE NO IDEA WHAT THE CTLR HAD ON HIS SCOPE.

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.