VOR or GPS-A @ KSMO

3 Answers

1. 
   

   
   

   John D Collins on Dec 22, 2015

   It is named “- A” because it is a circling approach and not assigned to a specific runway. Circling approaches are named starting from the beginning of the alphabet, at “-A”, then “-B” and so on. The Z, Y, X suffixes are used when there is an approach using the same runway and the same means of navigation (ILS, VOR, RNAV, NDB) to differentiate the procedures. They begin at the end of the alphabet and follow reverse order in the alphabet.

   This approach is a circling approach because it ends at the far end of runway 21 or the runway 3 end. It is way too steep to descend from the missed approach point to any specific runway, thus circling to either runway is required. Since it is the first circling approach for the VOR or GPS navigation systems, it starts at – A.

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2. 
   

   
   

   Russ Roslewski on Dec 22, 2015

   John, I think you may have unintentionally misled “lowtimepilot” regarding the missed approach point.

   There is never a consideration to be able to descend and land from the missed approach point, so the steepness of descent from the MAP is not a determining factor in making an approach circling-only.

   There are a few things at work on this procedure which complicate the situation, though.

   One, it’s an old GPS overlay approach, as denoted by the “vor OR gps” naming convention. Thus, it does not comply with current RNAV (GPS) approach criteria. If it did, the MAP would not be permitted to be past the approach end of the runway (but since this is okay on VOR approaches, it carried forward).

   Two, it’s the descent angle required from the FAF to the runway that is one thing used to determine whether a basically-straight-in aligned procedure can have straight-in minimums or not. From 2600 to 177 over about 5.9 nm (estimate) is greater than the maximum allowed for a straight-in approach (400 ft/nm)

   Indicentally, the FAA’s coordination site lists a new RNAV (GPS) procedure to both runways publishing in Sep 2016:
   https://www.faa.gov/air_traffic/flight_info/aeronav/procedures/application/?event=procedure.results&tab=productionPlan&nasrId=SMO#searchResultsTop

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3. 
   

   
   

   John D Collins on Dec 22, 2015

   Russ,

   All true, but the primary point was the naming convention, The approach only has circling minimums.

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