Basile-SCAviation 2011

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U.S. Deportment of 1ransportotlon Federal Aviation Administration JUL - -i mn Mr. Eric Basile SC Aviation, Inc.

4120 S. Discovery Drive Janesville, WI 53546

Dear Mr. Basile:

This letter is in response to your April 7, 2011 request for an interpretation of 14 C.F.R. § 135.225(a). You asked whether a pilot may consider both the reported visibility in the · body of a METAR and a surface visibility observation noted in the "Remarks" section of the same METAR report in determining that the "weather conditions are at or above the authorized minimums for that airport" as required by §135.225(a). 1 In your hypothetical scenario, the METAR shows a prevailing visibility of Y.. mile in the body of the report while the remarks sections lists a surface visibility of 1 Yz miles. The FAA has consistently followed a pqlicy that for the purpose of dispatch, release and continued operations, including beginning an instrument approach to an airport, "the worst weather condition in the main body or the remarks portion of a tenninal forecast, as well as any weather report used, is the controlling factor when selecting a destination or alternate airport." See, 8900.1, Volume 3, Chapter 26, Paragraph 3-2049. Paragraph 3- 2050 then recognizes that weather can change rapidly and requires a continuing watch over weather conditions for IFR part 135 terminal operations. As a result, readin,g these policies together, when a METAR report has two differing values in the body and the remarks section, the lower of the two values must be used to determine whether the approach can be initiated.

This is consistent with similar guidance in the Airman's Information Manual (AIM) in 7- 1-17 ( c), which states:

1 135.225 IFR: Takeoff, approach and landing minimums.

(a) Except to the extent permitted by paragraph (b) of this section, no pilot may begin an instrument approach procedure to an airport unless(!)That airport bas a weather reporting facility operated by the U.S. National Weather Service, a source approved by U.S. National Weather Service, or a source approved by the Administrator; and · (2) The latest weather report issued by that weather reporting facility indicates that weather conditions are at or above the authorized IFR landing minimums for that airport.

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c. When the prevailing visibility at the usual point of observation, or at the tower level, is less than 4 miles, certificated tower personnel will take visibility observations in addition to those taken at the usual point of observation. The lower of these two values will be used as the prevailing visibility for aircraft operations.

Previous legal interpretations have reinforced the above policy in the context of the regulation you are inquiring about. "The rationale behind the current regulation is that as long as one can show a combination of weather reports or forecasts indicating above minimum weather conditions at the estimated time of arrival (ETA) at the destination airport, the flight may be dispatched or released. However, the converse is also true, that when any combination of weather reports or forecasts show below minimum weather conditions at the destination airport at ETA, the aircraft may not be dispatched or released." See, Interpretation 1989-28, Letter to David P. Quinn from Donald P. Byrne, Acting Assistant Chief Counsel, Regulations and Enforcement Division (Oct. 6, 1989). Therefore, in the hypothetical scenario where the body of a METAR report indicates that visibility is below the authorized minimums required to comply with§ 135.225(a) and a differing report in the remarks section of the METAR indicates surface visibility to be at or above the authorized minimwns for that airport, the lower value in the body of the report must be used in determining whether an ILS approach can be commenced. We trust that the above responds to your concerns. This response was coordinated with the Air Transportation and Flight Technologies and Procedures Divisions of the Flight Standards Service. Should you have any further questions, please contact Robert H. Frenzel, Manager, Operations Law Branch in the Regulations Division of the Office of the Chief Counsel, at (202) 267-3073.

Sincerely,

. ~,p.... fa/JRebecca B. MacPherson Assistant Chief Counsel for Regulations, AGC-200