Originally Posted by
Airbubba
And, most EGPWS depictions already have more granular and useful data for terrain avoidance as you head for those hills. A similar scenario out of LAX is a common sim setup for the required terrain avoidance escape maneuver training in my experience.
It remains disturbing that the EVA pilots apparently did nothing in the vertical dimension after hearing "pull up" warnings from the EGPWS for seven seconds.
The data revealed that the system generated two sets of caution warnings to the pilots, and then a seven-second pull up alert that began at 0124:49, as the aircraft was turning just south of Mt. Wilson.
Like TCAS, EGPWS is a system of last resort -- i.e., by the time the "red alarm" goes off, standard separation and obstacle clearance have been grossly violated.
That's significantly different from the proposal to facilitate publication and electronic depiction of MVAs.
MVAs have been evaluated per criteria similar to those embodied in MEA/MOCAs -- specific vertical and horizontal margins are guaranteeing minimum obstacle clearance values. Those MEA/MOCA margins are not "emergency" EGPWS algorithms.
Many envision the cockpit display of MVA sectors as more akin to depiction of MEAs on airways rather than waiting for EGPWS to turn red or issue audible "last chance" alarms.
Saying that "we have EGPWS so we don't need MVA moving maps" is a bit like saying "we have TCAS so we don't need ATC". (And I realize that no one on here has said that.)
Would pilots prefer to have MVA information in the cockpit presented on a scalable moving map vs delaying action until the EGPWS to turn red and hollers "PULL UP" "PULL UP"?