ZID controller described a potential conflict event when an air carrier made an unexpected 40 degree...

Attributes
ACN	1082871
Time
Date	201304
Local Time Of Day	0001-0600
Place
Locale Reference	ZID.ARTCC
State Reference	IN
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	Cruise
Person 1
Function	Enroute Instructor
Qualification	Air Traffic Control Fully Certified
Person 2
Function	Captain
Experience	Flight Crew Last 90 Days 213 Flight Crew Type 10000
Events
Anomaly	Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

Narrative:

While conducting ojti I read the flight plan on a B737. It read: kstl.JHART1.rod.... When the B737 passed the kelly intersection; I noticed that he turned 40 degrees left towards vhp and towards an overflight also at FL330 (call sign unknown). After descending the B737 to FL300; I asked what clearance he had received that caused the turn at kelly towards vhp. He stated that he was given the jahrt departure then vhp direct rod and the [STAR] arrival. The B737 was then cleared direct to rod. I'm not sure if this was a clearance delivery problem; FMS issue; or misunderstanding on the pilot's part. This is the second time I have seen this happen in the past two weeks. Both events involved the same airline flights.

Original NASA ASRS Text

Title: ZID Controller described a potential conflict event when an Air Carrier made an unexpected 40 degree turn not indicated on the ATC route information.

Narrative: While conducting OJTI I read the flight plan on a B737. It read: KSTL.JHART1.ROD.... When the B737 passed the KELLY Intersection; I noticed that he turned 40 degrees left towards VHP and towards an overflight also at FL330 (call sign unknown). After descending the B737 to FL300; I asked what clearance he had received that caused the turn at KELLY towards VHP. He stated that he was given the JAHRT departure then VHP direct ROD and the [STAR] arrival. The B737 was then cleared direct to ROD. I'm not sure if this was a clearance delivery problem; FMS issue; or misunderstanding on the pilot's part. This is the second time I have seen this happen in the past two weeks. Both events involved the same airline flights.

Data retrieved from NASA's ASRS site as of July 2013 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.

ZID controller described a potential conflict event when an air carrier made an unexpected 40 degree turn not indicated on the ATC route information.