Andrew Gideon wrote:

G Farris wrote:


The missed approach is part of the procedure, and if you've done
good you have it all dialled-in, briefed and ready to fly.


LOC22 at KCDW requires the localizer for the missed. The NDB-A (which has a
GPS overlay now) also uses the same NDB in the missed approach procedure.

Not all approaches provide a decent transition to a missed approach in the
case of a failure of the primary NAVAID. I find that astonishing.

- Andrew


There is so much protected airspace for these procedures that a primary
nav failure will not probably create a safety issue. And, if the
aircraft has a GPS moving map that provides a redundant positive course
guidance alternative/backup.

In the case of the new RNAV (RNP) SAAAR procedures, GPS is presumed to
fail during the approach. If the missed approach can be serviced with a
Level 1 TERPs missed approach area (criteria that have been used for
RNAV (GPS) missed approach design for about three years now, the pilot
is presumed to be able to do short term dead recogning for extraction in
the event of loss of GPS. If, howver, the missed approach requires
smaller RNP values than provided by a Level 1 missed approach, then the
aircraft must have IRU positioning to fall back on with loss of GPS.