Air carrier large transport deviated from clearance heading deviation.

Attributes
ACN	105636
Time
Date	198903
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mdw
State Reference	IL
Altitude	msl bound lower : 2400 msl bound upper : 2400
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : mdw
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	departure sid : sid enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 200 flight time total : 22000 flight time type : 6000
ASRS Report	105636
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 200 flight time total : 7000 flight time type : 3000
ASRS Report	105529
Events
Anomaly	non adherence : far non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation
Situations
Publication	Unspecified

Narrative:

The wording on the midway 3 SID is not clear. We were cleared for takeoff heading 090 degree. Reading the SID gives you the impression you should turn north at 2400. As we switched to departure control I started to turn out of 2400'. Departure picked it right up and turned us back to 90 degree. No conflict, no problem, but I feel that the SID should not be so ambiguous.

Original NASA ASRS Text

Title: ACR LGT DEVIATED FROM CLRNC HEADING DEVIATION.

Narrative: THE WORDING ON THE MIDWAY 3 SID IS NOT CLEAR. WE WERE CLRED FOR TKOF HDG 090 DEG. READING THE SID GIVES YOU THE IMPRESSION YOU SHOULD TURN NORTH AT 2400. AS WE SWITCHED TO DEP CTL I STARTED TO TURN OUT OF 2400'. DEP PICKED IT RIGHT UP AND TURNED US BACK TO 90 DEG. NO CONFLICT, NO PROBLEM, BUT I FEEL THAT THE SID SHOULD NOT BE SO AMBIGUOUS.

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.