End_of_Descent
24th Dec 2013, 10:14
Hi all,
I am currently in a discussion on how the EGPWS peaks mode (shown at altitudes well above any terrain, where green color only is shown on the ND) behaves in particular situations. The discussion is on how to simulate EGPWS correctly.
One case I'm discussing is how the EGPWS terrain awareness display (TAD) looks over very high but still (more or less) flat terrain, namely over the Tibetian plateau when flying along Chinese airway L888 from KCA via SANLI towards ZUUU, e.g. between MUMAN and LUVAR. Two questions in particular here:
- how much percentage of the ND is covered with green color ("peaks")? Maybe someone has an EGPWS TAD photo taken on L888? That would be much appreciated.
- what is the "minimum" terrain figure on shown on the ND? (three-digit figures on the ND (left side on Boeings, right on Airbusses)
The other case is how EGWPS TAD would look over very, very flat terrain. I understand from Honeywell documents that EGPWS has a flat terrain switch. What happens over very flat terrain? Is the TAD showing all-green on the ND?
Basically it comes down to two questions:
- how is the min. elev. figure for EGPWS peaks mode calculated (see e.g. Airbus EGPWS ND lower attitude (http://www.andytracy.net/egpws.htm) )
- would EGWPS TAD show 80% or 100% of the ND area with green color?
Thanks for any comments.
Merry Christmas and best regards,
EoD
I am currently in a discussion on how the EGPWS peaks mode (shown at altitudes well above any terrain, where green color only is shown on the ND) behaves in particular situations. The discussion is on how to simulate EGPWS correctly.
One case I'm discussing is how the EGPWS terrain awareness display (TAD) looks over very high but still (more or less) flat terrain, namely over the Tibetian plateau when flying along Chinese airway L888 from KCA via SANLI towards ZUUU, e.g. between MUMAN and LUVAR. Two questions in particular here:
- how much percentage of the ND is covered with green color ("peaks")? Maybe someone has an EGPWS TAD photo taken on L888? That would be much appreciated.
- what is the "minimum" terrain figure on shown on the ND? (three-digit figures on the ND (left side on Boeings, right on Airbusses)
The other case is how EGWPS TAD would look over very, very flat terrain. I understand from Honeywell documents that EGPWS has a flat terrain switch. What happens over very flat terrain? Is the TAD showing all-green on the ND?
Basically it comes down to two questions:
- how is the min. elev. figure for EGPWS peaks mode calculated (see e.g. Airbus EGPWS ND lower attitude (http://www.andytracy.net/egpws.htm) )
- would EGWPS TAD show 80% or 100% of the ND area with green color?
Thanks for any comments.
Merry Christmas and best regards,
EoD