Thanks a lot for valuable input from all of you.
None. Quote Are you saying your new software update to EGPWS will allow you to keep it activated on arrival to a place using QFE? Our's will not. Unquote
To comment your question, pls be advised I’m referring to B737NGs with GPS installed. It’s my understanding the answer to yr question is yes. With the new updated P/N we are installing, we are allowed to remove a QFE limitation from the AFM. With the AFM limitation, we are not allowed ‘to fly in a QFE environment without disabling the enhanced features of the ground proximity warning system’, as Boeing express this. As I understand this, the updated EGPWC calculates geometric altitude, or true height above sea level, which allows for continuous EGPWS operation in QFE environment.
At this time I do not know the situation for other a/c types. Even though I find this information exchange very useful, I hope you’ll understand when I prefer not to go into more details here on the forum, as I’d hate to infringe Boeings possibly proprietary documentation.