Training Controller and his student report a loss of separation incident resulting in a go around during visual approach to Runway 26 at PHX. Both controllers lament the loss of control that resulted when the EAGUL 4 RNAV procedure was instituted.
Synopsis
Training Controller and his student report a loss of separation incident resulting in a go around during visual approach to Runway 26 at PHX. Both controllers lament the loss of control that resulted when the EAGUL 4 RNAV procedure was instituted.
Narrative
I was training on Finals on the Freeway sector. I took the radar handoff on Air Carrier X who was descending via the EAGUL4 arrival Runway 26 transition. When I took the radar hand off on Air Carrier Y; I saw that they were about 4 miles in-trail. Air Carrier Y was also descending via the EAGUL4 arrival. I watched to make sure that Air Carrier Y was slowing to a similar speed as Air Carrier X and noticed that Air Carrier Y was indeed slowing down. I cleared Air Carrier X for a visual approach and noticed that Air Carrier Y was still showing a faster speed than Air Carrier X (I assumed that the speed difference was from the altitude difference and that the airplane was slowing more than it actually was). After I cleared Air Carrier Y for a visual approach I went back to slow him down further. The speed still was in transition and I felt it was not going to be enough to hold minimal separation. (A square turn to final approach course was not an option since there was an aircraft on opposite base and I felt Air Carrier Y would overshoot the localizer). Then I gave Air Carrier Y a ten degree turn to push his turn on final further behind Air Carrier X. My OJTI asked Air Carrier Y if he had the Air Carrier X in-sight and Air Carrier Y acknowledged that he did. We used visual separation to clear Air Carrier Y and still reduced his speed to 150 KTS since Air Carrier Y's speed was still showing faster. Then I shipped Air Carrier Y to the Tower. Air Carrier Y thereafter became a go-around and subsequent investigation. I was notified that we had lost minimal separation outside 10 miles of PHX. I am unsure exactly what point the two aircraft lost separation; if it was before or after I tried to maintain the minimal separation.The EAGUL4 STAR is very fast and the airplanes are very high when they come to the Finals sector. I would recommend that the aircraft be taken off the STAR for more stabilized altitude and speeds.
Second reporter narrative
I was conducting OJT on the north final position. It was early in the session when this event occurred and it was the trainee's first day on this airspace configuration since the arrival and procedural changes at P50. Air Carrier X was descending via the EAGUL 4 arrival; Runway 26 transition. Air Carrier Y was closely behind Air Carrier X also descending via the EAGUL 4 arrival; Runway 26 transition. Air Carrier X reported the airport in sight. The trainee issued a heading to join final and cleared the aircraft for a visual approach to Runway 26. Shortly after; Air Carrier Y reported the airport in sight. The trainee issued a heading to join final and cleared the aircraft for the visual to Runway 26. Sometime during these clearances the trainee questioned the Arrival Controller on the spacing she was receiving. She was not comfortable there would be enough room for all aircraft she was handed off. I discussed this briefly with her and gave her a couple of tips to make it work. I also sensed she was uncomfortable with the new RNAV routes the aircraft were flying. We again discussed this briefly during the session. She was willing to continue working with the RNAV arrival routes.Between working the remaining aircraft and our discussion of the RNAV routes I noticed Air Carrier Y looked a little too close to Air Carrier X on final. I used the override and issued traffic to Air Carrier Y on Air Carrier X in front of him. Air Carrier Y reported traffic in sight. I instructed Air Carrier Y to follow Air Carrier X. Both aircraft were executing the visual approach to Runway 26. The trainee issued a 150 KTS speed restriction to Air Carrier Y and switched the aircraft to the Tower.Air Carrier Y executed a go-around. When that happened the FLM started a QAR investigation. It was though this investigation where it appeared a loss of separation may have occurred between these two aircraft. As I write this report the final outcome of the investigation was still pending.After Air Carrier Y went around and my further sense that the trainee was uncomfortable with the RNAV routes; I instructed the trainee to issue a heading and altitude assignment to all future inbound aircraft. This seemed to help her a great deal. I sensed and she even admitted later that she felt more in control. We continued training with no further issues.The new arrival routes and procedures have been a challenge to all of us at P50. My trainee is no exception to these challenges. One of my beefs with the new RNAV arrivals is; in my opinion; that there are several built in traps. There used to be safe guards built into our arrivals and facility procedures that would procedurally keep airplanes separated if something went wrong. Now those redundancies don't seem to exist and if I was to do nothing as a controller; airplanes can easily come together. Several examples of this can be seen with the EAGUL 4 and MAIER 4 arrivals; Runway 26 transitions. The EAGUL 4 arrival descends all the way to the runway at and angle towards the airport. This descent runs though the arrival routing of the MAIER 4 arrival. This seems dangerous to me.Another example of this is the EAGUL 4 routing itself. We used to be required on the feeder positions to vector aircraft on a base leg; perpendicular to the final. This created an angle that could be used to help separate and enhance spacing of aircraft. Since this no longer exists the feeder can leave aircraft on the arrival and it is up to the final controller to execute all vectors for spacing. Again; this seems dangerous and wrong to me.Though I feel we could have handled our event better I feel these new procedures had an impact on this situation and should definitely be looked at. It is my opinion that the feeder positions should be vectoring aircraft off the EAGUL RNAV arrival and assigned a heading perpendicular to the final in this airspace configuration. Further; the aircraft on this base leg should be capped at 8;000 FT which is 1;000 FT above the aircraft on the MAIER 4 arrival.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.