Date: 201808
Local time of day: 0601-1200
Location: NCT.TRACON, CA
Aircraft: B737-900
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Final Approach
Second aircraft: B737 Undifferentiated or Other Model
Reporter organization: Government
Reporter function: Approach
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Human-Machine Interface; Confusion
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Provided Assistance
Contributing factors: Weather; Procedure; Airspace Structure; Human Factors
Primary problem: Procedure

Narrative: The weather at SFO airport had been going in and out of and back and forth between marginal weather and clear openings on the SFO final all night. This is something that we as NCT approach controllers deal with at SFO airport; on almost a daily basis. The current observed; and official reported weather at both the SFO airport and the San Mateo Bridge; was such that we could conduct 'Expanded Charted Visual Flight Procedures'; and/or vector for visual approaches. However; aircraft set up for instrument approaches began reporting the land marks associated with CVFPs [Charted Visual Flight Procedures]; and the airport in sight; as well as aircraft set up for the parallel runway. So; the decision was made with the concurrence of the Operations Supervisor and Operations Manager; as we always have done in my 4 years here; we would no longer conduct CSPR [Closely Spaced Parallel Runway] operations; instead; we would operate using instrument approaches while also using visual separation due to the improved reported visibility by the pilots. We would no longer be operating under the rules of order 7110.308C and 7110.65X section 5-9-6. Instead we would be using the rules outlined in 7110.65X; Ch. 7. The rules outlined in the 7110.308C and 7110.65X section 5-9-6 from my understanding are designed to increase airport capacity during inclement weather; and to be more exact IMC; the 7110.308C Background states:'Increased airport capacity and reduced arrival delays under Instrument Meteorological Conditions (IMC) can be achieved by using the diagonal separation minima established in this order (1.0 NM diagonal separation for runway pairs listed in Appendix A and the dependent staggered separations listed in Appendix B) within successive pairs of arrivals to CSPR. As with all other simultaneous approach procedures that are designed to reduce the separation minima under IMC; visual separation is not authorized during the turn on to final approach.'Again; the key components of this background statement in the 7110.308C; is that the weather is IMC; which we were not; and the pilot reported weather was improving. As; we have historically done at SFO; we again decided to use instrument approach procedures while using visual separation to reduce phraseology by requesting the aircraft to report the airport in sight. The operation was working without incident as it has since I've been working approach and NORCAL TRACON; from the time we started until the incident that I am reporting on occurred. Aircraft X was set up and cleared on the ILS RWY 28R approach and was maintaining visual separation with an Aircraft Y cleared on the ILS RWY 28L approach. Both aircraft were cleared on a procedure (not on vectors). Aircraft Y deviated from his clearance for the ILS RWY 28L approach and flew through the RWY 28L localizer; as well as the RWY 28R localizer; then turned back into the path of Aircraft X. Speed control was used to allow for a slight stagger between the aircraft to avoid a situation where a resolution advisory could take place. However; due to the deviation by Aircraft Y from procedure; the closest proximity of the aircraft was .86NM and 200ft. This caused rightful concern by Aircraft X; and caused a TCAS RA with Aircraft Y. Both aircraft were asked if they would like to continue with the approach; and both aircraft decided to do that. Since I was notified about the incident; there was a reiteration of the rules in the 7110.308C via CEDAR that visual separation is not allowed until both aircraft are established on final approach. Furthermore; there was a face to face briefing; mind you the first of its kind since I've been here at NORCAL TRACON; stating that the only time dual instrument approaches could take place while using visual separation is in accordance with the 7110.308C Order. The problem with this being a fix on the issue that took place is this; the idea that a pilot deviation; specifically a blunder through final can only takeplace during inclement weather and/or during an instrument approach procedure is absurd. In fact; that's something that we deal with on a regular basis at SFO airport during VMC/CVFPs. My recommendation would be to brief pilots the importance of staying on set procedures or instructions by ATC to effect safety. Another possible solution would be to fix the intercept angle on the ILS RWY 28L procedure. The TIP TOE RWY 28L procedure allows for a more shallow intercept on final; assisting in preventing blunders or accidental spill over in the adjacent final approach course. Furthermore; if the idea that QC/Management/procedures department at NORCAL TRACON wishes to ensure that visual separation isn't being applied between aircraft conducting instrument approach procedures; that should have been briefed thoroughly; to ensure that the operation supervisors and CPC's [Certified Professional Controller] on the floor are clear on what we are and aren't allowed to do.




Synopsis: NCT TRACON Controller reported an operational error and trouble understanding an Order relating to the proper use of Closely Spaced Parallel Runways.