Sct controller described a visual approach event when traffic clear for approach to see made an unex...

Narrative:

A PA46 was cleared for a visual approach to gillespie field and transferred to the tower frequency. The pilot then started making a turn away from the airport; toward the traffic I had on the myf ILS final. The aircraft were about 5 miles apart when I issued traffic to the aircraft that I was working on the myf final. I called gillespie tower to insure that the pilot did not continue turning away from the airport. Traffic was not in sight; so I broke that traffic off the approach and sequenced the aircraft again. The aircraft may have gotten about 2.5 miles apart before divergence was established. Recommendation; I should have not trusted the pilot conducting the visual approach to follow procedures in the aim and fars; whereby pilots on a visual approach are to take the most expeditious route to the airport. I was not expecting the aircraft to begin a turn away from the airport. Even though the turn was slight; it was enough to cause me to take corrective action.

Original NASA ASRS Text

Title: SCT Controller described a visual approach event when traffic clear for approach to SEE made an unexpected turn away from the airport; creating a potential conflict with MYF traffic.

Narrative: A PA46 was cleared for a Visual Approach to Gillespie field and transferred to the Tower frequency. The pilot then started making a turn away from the airport; toward the traffic I had on the MYF ILS final. The aircraft were about 5 miles apart when I issued traffic to the aircraft that I was working on the MYF final. I called Gillespie Tower to insure that the pilot did not continue turning away from the airport. Traffic was not in sight; so I broke that traffic off the approach and sequenced the aircraft again. The aircraft may have gotten about 2.5 miles apart before divergence was established. Recommendation; I should have not trusted the pilot conducting the Visual Approach to follow procedures in the AIM and FARs; whereby pilots on a Visual Approach are to take the most expeditious route to the airport. I was not expecting the aircraft to begin a turn away from the airport. Even though the turn was slight; it was enough to cause me to take corrective action.

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	923296
Time
Date	201012
Local Time Of Day	1201-1800
Place
Locale Reference	SCT.TRACON
State Reference	CA
Aircraft 1
Make Model Name	PA-46 Malibu/Malibu Mirage/Malibu Matrix
Flight Phase	Landing
Route In Use	Visual Approach
Flight Plan	VFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types

Sct controller described a visual approach event when traffic clear for approach to see made an unexpected turn away from the airport; creating a potential conflict with myf traffic.