MEM Controller described an unsafe situation when local requirements for parallel approaches were not followed given the weather and supervisory directions.
Synopsis
MEM Controller described an unsafe situation when local requirements for parallel approaches were not followed given the weather and supervisory directions.
Narrative
An Air Carrier was inbound for the evening push with weather around the field. I was working the 2 Eastern parallels and Runway 27. We originally were landing south; but half-way thru the push turned the airport around to 36L/R and Runway 27 with staggered ILS approaches due to winds. The ASOS was reporting limited visibility and minimal ceilings. For this operation; the aircraft on final to 36R must be in sight by a 3 mile final; and the aircraft on final to Runway 27 must be in sight as well by a 3 mile final on their respective ILS'. On this evening we were seeing the aircraft on final to 36R at 1 1/2 SM and the aircraft on final to 27 at 2 SM. The Supervisor on duty told me to let him know and break out aircraft on final to 27 if they weren't in sight by a 2 mile final. So that is what I did. At the time; I was working other frequencies and concerned about issuing PIREPS; updating arriving aircraft on the current weather situation; and keeping the runways clear to keep go-arounds as much out of the equation as possible. I would recommend some form of additional training or refresher training be provided so that everyone knows the rules and implements the rules properly to ensure a much safer situation next time.
Second reporter narrative
Several FPL's caught me and were very concerned; noting 'this operation isn't legal'. I asked what they were talking about as I looked out the window. To the west; you could not see the ground. The RADAR showed a band of level 4 and 5 weather over the field. I looked to the east. It was dark; half of Runway 36R was not visible from the Tower; half of Runway 27 was not visible from the Tower. The supervisor had his head down reading something. As I was taking all this in the FPL's were telling me that we were running staggered approaches to the north parallels (36R and 36L); and converging approaches to Runway 27. My initial reaction was that they must be joking. I looked at the weather; and the visibility was 1 3/4 mile in heavy rain and mist. They assured me that they were not joking and pointed to the ASDE X and to the BRITE. There were aircraft on final for 36R and 27. There were also aircraft rolling out on both runways and they were not visible until they were halfway down the runway. I immediately asked the Supervisor what he was doing; this wasn't legal. He responded; 'What do you mean?' I explained that the 36R traffic and the 27 traffic were not separated from each other. He looked confused and said 'what are you talking about?' I then explained again to the Supervisor that aircraft short final for 27 are less than 3 miles apart from aircraft short final for Runway 36R. He said; 'Oh; I see what you are saying; it's OK we are providing visual separation.' I pointed out the window and asked; 'How are we providing visual separation; you can't even see the approach end of the runway?' As we were discussing the situation the band of level 4 and 5 moved east of us and we were in level 2 weather with improved visibility. The Supervisor pointed out the window and said; 'See; I can see that guy three miles out.' I looked at the aircraft in question and the airplane disappeared into a lower scud layer. I said; 'How are you providing visual separation to an airplane you can't see anymore?' He repeated; 'I respect your opinion; but I have a different opinion.' I asked again; 'What separation criteria are being used to separate the airplane on final for 36R and the one short final for 27?' He wouldn't answer my question. The other controllers told me that there had been several aircraft on both finals that had lost separation and that they had told the supervisor; but that he had chosen to ignore them. Recommendation; ensure that the Supervisor knows and understands separation requirements and when FPL's are telling you that something isn't legal; you need to seriously listen to them.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.