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- - EGPWS (https://www.pprune.org/tech-log/247086-egpws.html)

Quote:

Originally Posted by airmen

Captaincy means:

The captain can decide to override a GPWS warning when the aircraft is:

1000 ft vertically clear of clouds
1km horizontally clear of clouds
In 8.5 km of clear visibility
Flying in daytime
Obviously not in danger

I.e: when doing a visual approach

Is this paragraph straight out of the book "Ace the Technical Pilot Interview"? If so, can someone please confirm it as I have been looking but found no sources to confirm it, as we know the book is full of errors? If not, can you tell me if this is some rule or is this type specific?

Cheers.

In our classic 737s the EGPWS had for the reasons mentioned its own GPS receiver which was deemed more accurate in more situations than the pure dme/dme update. In the NGs that is not really a concern anymore as the usual ANP hovers around 0,02NM. Besides, you can retrofit the classics to use GPS position with the FMC as well, however that does cost money of course.

Didn't they install a new DME near INN now to increase "conventional" RNAV accuracy as backup to GNSS based RNAV? In other parts of austra too as far as i'm aware. Our main problem area back then was russia where there was no DME update available even in the moscow area, now that has changed as well.