wrote:


As a matter of regulation, the G/S is to be used as primary vertical
guidance only from the PFAF inbound. There are some places, where early
use of the G/S has resulted in airspace violations, LAX being the most
notable.

In the case cited, the CFI is nitpicking but is nonetheless legally
correct.

Tim,

Can you give an example of how an airspace violation could occur? It
seems that as long as the pilot doesn't descend below the minimum
altitude published for the segment of the approach he's in, then
descending on the glidepath can't put the aircraft any lower than
dropping down immediately to the minimum segment altitude at the
beginning of the segment. If he's in the Intermediate, then the
glidepath will more than likely keep him higher than dropping down to
the minimum altitude due to the length of the intermediate normally
compensating for the required altitude loss at 150 ft per mile optimum.
If the airspace violation would be from the aircraft being too high,
then perhaps the procedure should have a maximum altitude shown or the
controller issue a crossing restriction.
The glideslope intercept altitude is a minimum altitude, not a mandatory
or maximum altitude. From a TERPS standpoint there's no problem with
descending on the glideslope from 2000 on the procedure in question
instead of 1800.
If the pilot uses the glideslope for backup vertical guidance to give a
smooth transition to the final segment (while using the altimeter
readout outside the FAF to ensure he doesn't descend below 1800) then
what's wrong with that?

JPH