14 CFR §125.381

1. (a)Regardless of any clearance from ATC, if the reported weather conditions are less than that specified in the certificate holder's operations specifications, no pilot may—
   1. (1)Take off an airplane under IFR; or
   2. (2)Except as provided in paragraphs (c) and (d) of this section, land an airplane under IFR.
2. (b)Except as provided in paragraphs (c) and (d) of this section, no pilot may execute an instrument approach procedure if the latest reported visibility is less than the landing minimums specified in the certificate holder's operations specifications.
3. (c)A pilot who initiates an instrument approach procedure based on a weather report that indicates that the specified visibility minimums exist and subsequently receives another weather report that indicates that conditions are below the minimum requirements, may continue the approach only if either the requirements of § 91.176 of this chapter, or the following conditions are met—
   1. (1)The later weather report is received when the airplane is in one of the following approach phases:
      1. (i)The airplane is on a ILS approach and has passed the final approach fix;
      2. (ii)The airplane is on an ASR or PAR final approach and has been turned over to the final approach controller; or
      3. (iii)The airplane is on a nonprecision final approach and the airplane—
         1. (A)Has passed the appropriate facility or final approach fix; or
         2. (B)Where a final approach fix is not specified, has completed the procedure turn and is established inbound toward the airport on the final approach course within the distance prescribed in the procedure; and
   2. (2)The pilot in command finds, on reaching the authorized MDA, or DA/DH, that the actual weather conditions are at or above the minimums prescribed for the procedure being used.
4. (d)A pilot may execute an instrument approach procedure, or continue the approach, at an airport when the visibility is reported to be less than the visibility minimums prescribed for that procedure if the pilot uses an operable EFVS in accordance with § 91.176 of this chapter and the certificate holder's operations specifications for EFVS operations, or for a holder of a part 125 letter of deviation authority, a letter of authorization for the use of EFVS.