B737 Undifferentiated or Other Model
Air Traffic Control Fully Certified
Situational Awareness; Communication Breakdown
Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance
Human Factors; Procedure; Airport
A Cessna was pointed out to me doing an NDB approach into the Troutdale Airport. A B737 was on final for 28L and I noticed that they were at the same altitude; both descending; converging as the Cessna was north northeast bound to TTD and the B737 was on final. The B737 came over to me and I called traffic right away on the Cessna for him to which he reported that he had the Cessna in sight. I instructed him to maintain visual separation with the Cessna and he replied that he was already instructed to do so and would comply. There was no reason for these two aircraft to get so close. By the time I talked to the B737 there was approximately 1 to 1.5 miles between them at the same altitude and the distance shrunk by the time they passed. Final should have made a bigger hole for the Cessna to complete his practice approach into TTD; as well as call me to advise that the B737 had the Cessna in sight. This has been an ongoing problem with practice approaches into TTD with finals aircraft into Portland.
PDX Controller described a developing conflict event between a PDX Air Carrier arrival for Runway 28L and Cessna conducting a NDB Approach to TTD. The reporter noted the TRACON should have provided more spacing.