Aus controller observed an apparent incorrect path flown by an aircraft assigned the centex four SID...

Narrative:

A SR22 received the following clearance from aus clearance delivery: aus CWK4 tnv mlu. I radar identified the aircraft; issued a climb; and then cleared the aircraft direct to ilexy intersection to 'intercept and resume the centex four departure'. Some time later I observed this aircraft far north of the assigned route of flight; and far past the ilexy intersection. I advised the pilot that he had overshot the assigned route; and I issued a new heading to join the centex four departure. The pilot insisted that he had dialed-in the correct 'navys intersection'; and it was at this point that I realized what had happened. There is a tnv (navasota transition) on the centex four departure; as well as a navys transition. Pilots often confuse navasota with navys due to the similar sounding fix and NAVAID transitions on the centex four departure. This issue has been previously reported. I contacted ZHU and advised them of what had happened; and switched the aircraft once I observed that he was turning back onto the proper route of flight. Such a simple fix... Just change navys fix and/or transition to a different name.

Original NASA ASRS Text

Title: AUS Controller observed an apparent incorrect path flown by an aircraft assigned the CENTEX Four SID discovering similar sounding fix names on the SID likely caused the confusion.

Narrative: A SR22 received the following clearance from AUS Clearance Delivery: AUS CWK4 TNV MLU. I RADAR identified the aircraft; issued a climb; and then cleared the aircraft direct to ILEXY Intersection to 'intercept and resume the CENTEX Four Departure'. Some time later I observed this aircraft far north of the assigned route of flight; and far past the ILEXY Intersection. I advised the pilot that he had overshot the assigned route; and I issued a new heading to join the CENTEX Four Departure. The pilot insisted that he had dialed-in the correct 'NAVYS Intersection'; and it was at this point that I realized what had happened. There is a TNV (Navasota Transition) on the CENTEX Four Departure; as well as a NAVYS Transition. Pilots often confuse NAVASOTA with NAVYS due to the similar sounding FIX and NAVAID Transitions on the CENTEX Four Departure. This issue has been previously reported. I contacted ZHU and advised them of what had happened; and switched the aircraft once I observed that he was turning back onto the proper route of flight. Such a simple fix... just change NAVYS Fix and/or Transition to a different name.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	975096
Time
Date	201110
Local Time Of Day	1801-2400
Place
Locale Reference	AUS.TRACON
State Reference	TX
Aircraft 1
Make Model Name	SR22
Flight Phase	Cruise
Route In Use	SID CENTEX Four
Flight Plan	IFR
Person 1
Function	Approach Departure
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	Deviation - Procedural Clearance Deviation - Track / Heading All Types

Aus controller observed an apparent incorrect path flown by an aircraft assigned the centex four SID discovering similar sounding fix names on the SID likely caused the confusion.