Small pilot cleared into controlled zone and cleared to land under special VFR is informed on downwind leg by tower that reported visibility is now less than 1 mile, that is, below special VFR minimums.
Synopsis
Small pilot cleared into controlled zone and cleared to land under special VFR is informed on downwind leg by tower that reported visibility is now less than 1 mile, that is, below special VFR minimums.
Narrative
Rewritten in plain English from NASA’s original all-caps telegraphic report — facts, figures, and terminology preserved.
Prior to the beginning of the flight at approximately XX30, the weather at Bethel was forecast to be predominately greater than basic VFR, and the visibility was not forecast to be less than 3 miles. Upon returning to Bethel, while piloting a lifeguard flight, the visibility was reported to be 1 1/2 miles with a high ceiling.
Bethel tower gave me a special VFR clearance to enter the controlled zone and required that I report established on right downwind, which I did. Just seconds prior to my turning onto right base, the tower reported new visibility at 3/4 mile. While I was on base leg, tower asked my intentions—and I replied, 'to continue my pattern.' Thereupon I landed without incident.
Note: I was cleared to land by the tower after reporting my downwind leg and before receiving the report of new visibility of 3/4 mile. Air Reg 91.107D(1) - 'Special VFR weather minimums': D) No person may takeoff or land an aircraft (other than a heli) at any airport in a controlled zone under VFR—1) unless ground visibility at that airport is at least 1 SM.
Show the original NASA report (verbatim, telegraphic)
PRIOR TO THE BEGINNING OF THE FLT AT APPROX XX30; THE WX AT BETHEL WAS FORECAST TO BE PREDOMINATELY GREATER THAN BASIC VFR; AND THE VISIBILITY WAS NOT FORECAST TO BE LESS THAN 3 MI. UPON RETURNING TO BETHEL; WHILE PILOTING A LIFEGUARD FLT; THE VISIBILITY WAS RPTED TO BE 1 1/2 MI WITH A HIGH CEILING. BETHEL TWR GAVE ME A SPECIAL VFR CLRNC TO ENTER THE CTL ZONE AND REQUIRED THAT I RPT ESTABLISHED ON RIGHT DOWNWIND; WHICH I DID. JUST SECS PRIOR TO MY TURNING ONTO RIGHT BASE; THE TWR RPTED NEW VISIBILITY AT 3/4 MI. WHILE I WAS ON BASE LEG; TWR ASKED MY INTENTIONS--AND I REPLIED; 'TO CONTINUE MY PATTERN.' THEREUPON I LANDED W/O INCIDENT. NOTE: I WAS CLRED TO LAND BY THE TWR AFTER RPTING MY DOWNWIND LEG AND BEFORE RECEIVING THE RPT OF NEW VISIBILITY OF 3/4 MI. AIR REG 91.107D(1) - 'SPECIAL VFR WX MINIMUMS': D) NO PERSON MAY TKOF OR LAND AN ACFT (OTHER THAN A HELI) AT ANY ARPT IN A CTL ZONE UNDER VFR--1) UNLESS GND VISIBILITY AT THAT ARPT IS AT LEAST 1 SM.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.