Honeywell MK VIII - Page 27

060-4314-000 • Rev. C - May 2004
MK VI & MK VIII EGPWS Pilot Guide
27
Terrain
Clearance
Floor
Continued
Improved TCF Envelope
Improved TCF Envelope Plan View
The alert envelope is limited to a minimum of 245 feet AGL adja-
cent to the runway as illustrated in the following diagrams. The
Envelope Bias Factor is reduced (moved closer to the runway)
when higher accuracy aircraft position and runway position in
-
formation is available. This is typically 1/3 to 1 nm, varying as a
function of position accuracy, providing protection against landing
short events. With version -022 and later models, the envelope
bias factor is reduced to 1/4 nm if runway and position data is of
high integrity.
1/2 Runway Length
(Minimum Elevation Number)
Envelope Bias Factor
TCF Alert Envelope
12NM
4NM
15NM
700'
30'
400'