Citation CE560 flight crew has a track heading deviation during departure from mdw.

Attributes
ACN	721792
Time
Date	200612
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mdw.airport
State Reference	IL
Altitude	msl bound lower : 2500 msl bound upper : 3000
Environment
Flight Conditions	IMC
Weather Elements	Rain
Light	Night
Aircraft 1
Controlling Facilities	tracon : c90.tracon
Operator	general aviation : corporate
Make Model Name	Citation V
Operating Under FAR Part	Part 91
Flight Phase	climbout : initial
Route In Use	departure sid : midway
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 100 flight time total : 3800 flight time type : 350
ASRS Report	721792
Person 2
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 90 flight time total : 12000 flight time type : 1400
ASRS Report	722769
Events
Anomaly	non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued alert flight crew : returned to intended or assigned course
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

I was the PF taking off on runway 22R out of mdw. Our instructions were to fly the midway 4 departure off of runway 22R. Our takeoff clearance out of runway 22R was to execute a right turn to a heading of 110 degrees while climbing to 3000 ft MSL. After liftoff; when I proceeded to execute the right turn to the assigned heading of 110 degrees; the captain questioned me and informed me that it was to be a left turn to a heading of 110 degrees. I disagreed with him; but we both failed to confirm with midway tower and I proceeded to make the left turn to a heading of 110 degrees. Once the tower controller realized that we were on a left turn; he instructed us to immediately execute a right turn to the previously assigned heading of 110 degrees. I immediately corrected the deviation and executed the right turn to the assigned heading. There were no further queries from the controller. It was a particularly busy night at midway that day; low visibility and rain prevailed and the WX had an impact on delaying arrs and departures. I believe that operating under those conditions can be challenging and stressful to any pilot; thus contributing to our mistake. I also believe that not confirming with the controller before deciding to make the left turn was definitely a communication breakdown on our part.

Original NASA ASRS Text

Title: CITATION CE560 FLT CREW HAS A TRACK HDG DEV DURING DEP FROM MDW.

Narrative: I WAS THE PF TAKING OFF ON RWY 22R OUT OF MDW. OUR INSTRUCTIONS WERE TO FLY THE MIDWAY 4 DEP OFF OF RWY 22R. OUR TKOF CLRNC OUT OF RWY 22R WAS TO EXECUTE A R TURN TO A HDG OF 110 DEGS WHILE CLBING TO 3000 FT MSL. AFTER LIFTOFF; WHEN I PROCEEDED TO EXECUTE THE R TURN TO THE ASSIGNED HDG OF 110 DEGS; THE CAPT QUESTIONED ME AND INFORMED ME THAT IT WAS TO BE A L TURN TO A HDG OF 110 DEGS. I DISAGREED WITH HIM; BUT WE BOTH FAILED TO CONFIRM WITH MIDWAY TWR AND I PROCEEDED TO MAKE THE L TURN TO A HDG OF 110 DEGS. ONCE THE TWR CTLR REALIZED THAT WE WERE ON A L TURN; HE INSTRUCTED US TO IMMEDIATELY EXECUTE A R TURN TO THE PREVIOUSLY ASSIGNED HDG OF 110 DEGS. I IMMEDIATELY CORRECTED THE DEV AND EXECUTED THE R TURN TO THE ASSIGNED HDG. THERE WERE NO FURTHER QUERIES FROM THE CTLR. IT WAS A PARTICULARLY BUSY NIGHT AT MIDWAY THAT DAY; LOW VISIBILITY AND RAIN PREVAILED AND THE WX HAD AN IMPACT ON DELAYING ARRS AND DEPS. I BELIEVE THAT OPERATING UNDER THOSE CONDITIONS CAN BE CHALLENGING AND STRESSFUL TO ANY PLT; THUS CONTRIBUTING TO OUR MISTAKE. I ALSO BELIEVE THAT NOT CONFIRMING WITH THE CTLR BEFORE DECIDING TO MAKE THE L TURN WAS DEFINITELY A COM BREAKDOWN ON OUR PART.

Data retrieved from NASA's ASRS site as of January 2009 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.