KEWB ILS 5 approach question

5 Answers

1. Best Answer
   
   

   
   

   Mark Kolber on Dec 21, 2017

   A bit of an semi-educated guess.

   In both cases, the text of the notes is in a standard form, so “AP” was included in the note authorizing the reduction in visibility despite the apparent contradiction with the note precluding use of an AP-coupled approach below a certain altitude.

   I would read it as a general case to specific specific case rule and, for example, if I were using an autopilot with an FD mode, decouple the AP reaching 470 and continue down based on the FD.

   +2 Votes 2 Votes  0 Votes

2. 
   

   
   

   KDS on Dec 22, 2017

   I don’t know if this will add any light or just make it more confusing, but here is what FAA Order 8260.19F has to say about “Autopilot coupled approach NA below”:

   (6) ILS/GLS restrictions. For GLS approaches, pending further evaluation by the FAA, autoland using GBAS is prohibited; use “Chart note: Autopilot coupled approach NA below (Decision Altitude).” Where flight inspection or Aircraft Certification Services establishes a restriction to the ILS/GLS approach, a NOTAM will be issued, and the restriction will be published in the Airport/Facility Directory (AFD). Where the restriction affects landing minimums or the MAP, issue an appropriate NOTAM. Publish a note using the same wording a s stated in the flight inspection report; e.g., “Chart profile note: ILS unusable inside DA.” No note is required for an unusable LOC back course, or for a LOC lateral coverage restriction with no terminal route through the restricted area.
   (a) If the LOC will not provide adequate course guidance in the area between the MM and runway threshold, use: “Chart profile note: ILS unusable from MM inbound.” Where an MM is not installed, flight inspection may provide a NM distance from threshold, or altitude, at which the ILS is not usable.
   (b) When the GS will not provide satisfactory vertical guidance, restrict its use above or below a specific altitude. Use: “Chart profile note: GS unusable below/above (altitude).”
   (c) When GS indications can be received on a LOC back course approach, use “Chart profile note: Disregard GS indications.”
   (d) When the rate of reversal in the GS exceeds the tolerances of Order 8200.1, United States Standard Flight Inspection Manual, establish a restriction for autopilot coupled approach 50 feet above the point (MSL) where the out-of-tolerance condition exists. Use: “Chart note: Autopilot coupled approach NA below (Decision Altitude).” Flight Inspection may also request that an autopilot coupled approach not be allowed at all. If that is the case, use: “Chart note: Autopilot coupled approach NA.”
   (e) When terrain, obstacles, descent gradient, etc., do not allow the use of a LOC procedure associated with the ILS when the GS is not used, place NA in the visibility column for each LOC category affected. If, in such an instance, another procedure must be used instead, enter the following in the Notes section: “Chart planview note: When GS not used, use LOC RWY 26 procedure.”

   0 Votes 0 Votes  0 Votes

3. 
   

   
   

   Vince R on Dec 22, 2017

   @Mark: Thanks for the explanation – begs a related question…without posting in here or getting the opinion of my local CFI, is there a more formal way to get clarification on questions like these, perhaps from the FAA directly? I mean, in this case it’s pretty trivial, especially since I’m not going if I need to worry about whether required visibility is RVR 1800 or 2400. But at best, the wording is confusing…feels like there should be a way to question or report these things somehow.

   0 Votes 0 Votes  0 Votes

4. 
   

   
   

   John D Collins on Dec 22, 2017

   You can always send a question or report an error via email to 9-AMC-Aerochart@faa.gov or call their 1-800-638-8972. It is printed on page 1, Table of Contents, Digital Terminal Procedures Supplemental and on page 1 of the Chart Supplement, aka the AFD.

   +1 Votes 1 Votes  0 Votes

5. 
   

   
   

   Vince R on Dec 27, 2017

   Wanted to share that I took John Collins’ suggestion and asked the FAA directly. Here’s the response I received:

   “…the statement “FD or AP or HUD to DA” is a standard phrase, and cannot cover all contingencies, so it will sometimes be accompanied with a modifier, such as “Autopilot coupled approach NA below 470”. When these are combined, the interpretation is “1800 RVR authorized with use of FD or AP or HUD to DA except AP may not be used below 470.” . Therefore, only manual use of FD or HUD is allowed to continue below 470’ MSL to the DA…”

   In addition to the answer itself (which is pretty close to Mark Kolber’s original response – thank you Mark), I’m completely impressed that I was able to pose a question to the authorities at the FAA and receive a thoughtful answer within 24 hours.

   +1 Votes 1 Votes  0 Votes