NTSB report - ILS and ATC. How does it all come together?

Steven P. McNicoll wrote:
"Sam Spade" wrote in message
news:A5Vlg.179419$bm6.137774@fed1read04...

How do you conclude that?

A decision altitude is a minimum approach altitude, too, in a broad use of
a term that lacks any official definition.



The term would be "decision height" in the US, not "decision altitude".
It's an MDA because nothing else fits.

I can't make such an inference from an NTSB report that fails to use the
FAA definitiona, thus creating vagueness where precision is required.

As to the US, the FAA is in transition from DH to DA so they can
harmonize with the rest of the world. You need to catch up on your
reading; i.e., AIM 5-4-5-4:

4. Chart Terminology
(a) Decision Altitude (DA) replaces the familiar term Decision Height
(DH). DA conforms to the international convention where altitudes relate
to MSL and heights relate to AGL. DA will eventually be published for
other types of instrument approach procedures with vertical guidance, as
well. DA indicates to the pilot that the published descent profile is
flown to the DA (MSL), where a missed approach will be initiated if
visual references for landing are not established. Obstacle clearance is
provided to allow a momentary descent below DA while transitioning from
the final approach to the missed approach. The aircraft is expected to
follow the missed instructions while continuing along the published
final approach course to at least the published runway threshold
waypoint or MAP (if not at the threshold) before executing any turns.

The DH (Decision Height, the height
at which a decision must be made during an instrument approach where an
electronic glideslope is provided to either continue the approach or to
execute a missed approach) for the full ILS RWY 36 was 264 MSL, 200' above
the TDZE (Touchdown Zone Elevation, the highest elevation in the first 3000'
of runway) of 64'. The MDA (Minimum Descent Altitude, the lowest altitude
to which descent is authorized on final approach in execution of a standard
instrument approach procedure where no electronic glideslope is provided)
for the ILS RWY 36 to straight-in localizer minimums was 440 MSL, 376' above
the TDZE.

Think of an MDA as an altitude to be maintained while a DH is an altitude to
be flown through.

Thanks for the flying lesson.

Having said that there is no logical reason for the NTSB investigator in
this report to have focused on the HAT of the sraight-in LOC MDA rather
than the HAT of the precision DA. Both should have been discussed since
the pilot could have been flying either the NPA or PA profile.





Yes, but "above ground level" is a term of ignorance.



Not at all, the term is used quite often in aviation.


But, not in reference to approach and landing minimums other than HAA
and HAT, which have precise definitions and are not valid as AGL values
anywhere along the final approach course (excepting CAT II RAs, which
are not applicable to this accident).

"Sam Spade" wrote in message
news:w5Ylg.179436$bm6.143818@fed1read04...

I can't make such an inference from an NTSB report that fails to use the
FAA definitiona, thus creating vagueness where precision is required.


It appears you confused yourself by snipping too much of the quote.



As to the US, the FAA is in transition from DH to DA so they can harmonize
with the rest of the world. You need to catch up on your reading; i.e.,
AIM 5-4-5-4:


No. The IAP still uses DH. I'll continue to use current terminology.



Thanks for the flying lesson.


You're welcome.