Date: 201401
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: IMC
Light: Night
Aircraft: EMB ERJ 145 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B ZZZ
ATC / advisory: Tower ZZZ
Second aircraft: EMB ERJ 170/175 ER/LR
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Communication Breakdown; Situational Awareness; Time Pressure
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter Fuel Issue
Detector: Person Air Traffic Control
Result: General None Reported / Taken
Contributing factors: Procedure; Human Factors; Airport; Weather
Primary problem: Human Factors

Narrative: I was working Local Control at night; and the weather had been degrading from VFR to MVFR to IFR throughout the evening. However; fog developed at a rate nobody in the facility anticipated; and while landing Runway 23R the RVR's decreased below the ILS minimums. Three aircraft on approach were unable to land; and then the process of switching the arrival runway to Runway 5L began (Runway 5L is capable of ILS CAT II/III operations). This resulted in nearly a dozen aircraft within close proximity to the airport expecting to land; and the Arrival Controller held each one via RADAR vectors. Also; aircraft were unable to land at satellite airports and diverted to ZZZ. Procedures for verifying the capability of the ILS system and runway environment require an Airport Ops vehicle to visually inspect the approach lights and entire length of the runway. My Tower CIC called downstairs to the TRACON Supervisor and coordinated that no arrivals were to be switched to the Tower until after the airfield vehicle completed the inspection and I explicitly authorized arrivals to Runway 5L. Due to the fog; the airfield vehicle took a long time (at least 10 minutes; I'd guess) to reach the distant runway threshold to begin the inspection. While waiting; the FLM/TRACON Supervisor called the Tower cab repeatedly; either to the CIC or myself on Local Control for an update. I made it clear that the airport vehicle was limited by the weather and doing her best to complete the inspection. When I observed one aircraft tracking the localizer inbound and saw a second aircraft turning towards the airport; I quickly hit the 'monitor' button to listen to the Final Controller. He was issuing approach instructions; so I called him and reminded him that I could accept no arrivals until the situation was verified as compliant with CAT II/III approaches. The TRACON Supervisor continued to call for updates; and stated that many aircraft were complaining about the amount of fuel on board. I may have talked to the Final Controller; too; but I can't remember which individual indicated that airplanes would be cleared for approaches to the runway; despite the lack of a safety inspection. I believe the TRACON Supervisor ordered the Final Controller to resume arrivals. After 5 aircraft successfully landed; reported clear of the runway; and safely made it to the gate; I again coordinated with the Final Controller for spacing/time to complete the runway light inspection. Foremost; a timely runway change would have been helpful. The degradation of the weather below CAT I minimums was a surprise. Better planning/anticipation by all parties would have allowed this event to be anticipated. Related to that; timely coordination between Tower; TRACON; and airport authority could have been effected better as well. Also; the RADAR Controller issuing approach clearances seemed premature; despite its apparent urgency. I was never told by another controller that any of the aircraft involved reported 'minimum fuel' or 'emergency fuel.' To my knowledge; none of the aircraft HAD to land without incurring a further 5-10 minute delay.




Synopsis: Local Controller described an unsafe condition when an untimely runway change; necessitated by weather; resulted in traffic landing prior to the completion of the required runway lighting checks.