rduarte see the EGPWS descriptions available from the Honeywell links above.
The new ‘EGPWS’ modes are described as ‘Enhanced’; the descriptions of modes 1-6 are essentially the ‘old’ GPWS. However, note that the warning logic for all modes (particularly the Enhanced capabilities) is under continuous review and may have been updated on several occasions. Operators should frequently check for system software revisions in addition to the terrain, runway, and obstacle database revisions. References to all aspects of these updates are in the Honeywell website.
EGPWS also includes optional ‘peeks’, geometric altitude, and obstacle modes, each offering major safety advantages; other new and revised operating modes are being developed.
The obstacle mode is available in all EGPWS ‘boxes’ although not all aircraft have been configured. Operators should seriously consider activating the obstacle mode (minor mod – wire change); there has been at least one large commercial aircraft ‘save’ due to an obstacle warning – and at least two near misses without the mode activated.
Originally Posted by
Mayday1215
In laymans terms, the EGPWS will give you warning for rising terrain ahead of you, whilst the GPWS will not be able to give you same warning.
This is a very limited description; EGPWS warnings will be given for any terrain (rising, level or falling) whenever the aircraft infringes the alerting or warning boundaries.
Originally Posted by
chornedsnorkack
EGPWS is only as good as the database, isn’t it?
No. The ‘old GPWS’ modes still work even if the Enhanced terrain functions are inhibited. The enhanced databases are comprehensive, highly reliable and updated regularly; the Honeywell web site has the technical details. If a new airport/runway is not in the database then report it to Honeywell. If you get an alert or warning, report those also – air safety report. All events are recorded in EGPWS memory and can be downloaded to assist with an investigation. All events must be investigated to establish the reasons for the alert. Follow the philosophy that there are ‘no false warnings’ with EGPWS; there is always a reason, and considering the alternatives in the air is not an option.
Originally Posted by
Miles Magister
If your EGPWS warning activates when you are IMC then you must follow it. If you are VMC then you can make a Captaincy decision.
Many operators are considering removing the Captains decision in ‘VMC’ as EGPWS is a highly reliable system. With a warning in VMC the aircraft is not where it ought to be – it is not on a safe flight path. A recent FSF presentation identified several instances where crew did not react correctly (believing that they were VMC) and the aircraft narrowly escaped an accident. Human error – believing that you know where you are was a dominant contribution as was night ‘VMC’ black hole illusions – low approach and you do not realize – both pilots suffers the same effect.
EGPWS uses advanced technology, is highly reliable, and provides excellent safety displays in normal operation – always display the terrain on one EFIS during take off and particularly during descent and approach; this may prevent an alert that you did not expect – and a visit to the Chief Pilots Office.