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Old 23rd Aug 2006, 12:16
  #45 (permalink)  
Zeffy
 
Join Date: Feb 2006
Location: USA
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Drop me off miles from the runway...

Please forgive the slight digression (another man's hijacking?), but doesn't this incident brightly illuminate the hazards of "IFR drop-offs at a point in space" approach procedures? -- i.e., those with circling-only minima and very high HAA's/HAT's, those with lengthy visual segments, etc.

Irrespective of the cause (crew error, scud, precip, etc.) -- initiating a missed approach from a point beyond the MAP and/or below MDA/DA is fraught with risks.

RNP_RNAV procedures have the potential to greatly reduce risk at locations like LXGB. For example, note that two procedures at another challenging airport not only provide continuous vertical guidance and vastly improved operating minima, they also offer positive course guidance throughout the missed approach segment.
http://www.aip.net.nz/pdf/NZQN_45.3_45.4.pdf

Obviously, RF (Radius to Fix) legs provide the procedure designer enormous flexibility.

Procedures like the NZQN RNAV imply the need for GPS-updating of the FMS in addition to FD logic that sustains LNAV-coupling in the event of a GA selection. Dropping to TRK, HDG or ROLL HOLD won't do a satisfactory job of keeping the airplane in the middle of the fairway, especially when the DA point occurs in a turn.
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