Figure: Example "Descent Angle NA" approach, from SAIB HQ-14-25, p. 2.

Eddie Sez:

It makes sense to use a Continuous Descent Final Approach (CDFA) on most non-precision approaches, for more about that see: Instrument Procedures / Continuous Descent Final Approach (CDFA). But what about for straight in approaches where the FAA says "Descent Angle NA" on the chart?

There are two things to keep in mind here:

  1. Once you descend below any published altitude, including the MDA, obstacle clearance is your responsibility. If the approach has a certified visual descent segment, such as on an ILS, an RNAV(GPS) with LNAV/VNAV minimums, or one with PAPI or VASI vertical guidance, you have the additional reassurance that the vertical path is okay within the specified margins.

  2. You may want to consider flying an approach other than one with "Descent Angle NA" noted if your FMS has issues with these types of approaches. I can't answer this for you, but as of October 2015, we in the Honeywell world have to be wary of these approaches. (More about that below.)

What follows are quotes from the relevant regulatory documents, listed below, as well as my comments in blue.


Background

[SAIB HQ-14-25, p. 1.]


Honeywell Update (October 2015)

We in the Honeywell world are adversely impacted . . .

[Honeywell Direct-To, October 2015]


References

Honeywell Direct-To October 2015, Advisory Vertical Guidance with No Published Vertical Descent Angle.

Special Air Worthiness Information Bulletin (SAIB) HQ-14-25, FMS and GPS Equipment Advisory Vertical Guidance with no Published Vertical Descent Angle, August 26, 2014.