Instructor pilot reported confusion with a similar fix name that caused the flight to be off course.

Attributes
ACN	1359921
Time
Date	201605
Local Time Of Day	0601-1200
Place
Locale Reference	C90.TRACON
State Reference	IL
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Transport
Operating Under FAR Part	Part 91
Flight Phase	Initial Climb
Route In Use	SID MIDWAY2
Flight Plan	IFR
Person 1
Function	Instructor
Qualification	Flight Crew Flight Instructor Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 3510 Flight Crew Type 15
Events
Anomaly	ATC Issue All Types Deviation - Procedural Clearance Deviation - Track / Heading All Types

Narrative:

During our initial call to midway clearance; we were assigned the following route for weather upon which it was read back and spelled to the controller:midway.2 aceto adell arlyn stl...etcon departure; we were assigned a heading from chicago departure and then asked to proceed to aceto..upon completion of the turn we were told we weren't proceeding toward the correct fix. We then clarified the fix with the similar spelling of another fix acito.

Original NASA ASRS Text

Title: Instructor pilot reported confusion with a similar fix name that caused the flight to be off course.

Narrative: During our initial call to Midway clearance; we were assigned the following route for weather upon which it was read back and spelled to the controller:MIDWAY.2 ACETO ADELL ARLYN STL...ETCOn departure; we were assigned a heading from Chicago departure and then asked to proceed to ACETO..upon completion of the turn we were told we weren't proceeding toward the correct fix. We then clarified the fix with the similar spelling of another fix ACITO.

Data retrieved from NASA's ASRS site 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.