Runway Field Clearance Floor - Honeywell EGPWS MK V Pilot's Manual

Runway In -210-210 and later versions, a Runway Field Clearance
Floor feature is included. This is similar to the TCF feature
Field
except that RFCF is based on the current aircraft position and
Clearance
height above the destination runway, using Geometric
Floor
Altitude (in lieu of Radio Altitude). This provides improved
protection at locations where the runway is significantly
higher than the surrounding terrain as illustrated below.
With version -218-218 and later models, the RFCF envelope
is moved from 1nm to 1/2nm if runway and position data is of
high integrity.
TCF and RFCF alerts result in illumination of the EGPWS
caution lights and the aural message "TOO LOW
TERRAIN". The audio message is provided once when
initial envelope penetration occurs and again only for
additional 20% decreases in Radio Altitude. The EGPWS
caution lights will remain on until the TCF and RFCF
envelopes are exited.
System Description
28
RFCF Ceiling (300 ft above field)
Krf
Field
Elevation
Runway
End
5500
5000
4500
4000
3500
3000
2500
2000
1500
-2 -1
Mark V and Mark VII EGPWS Pilot's Guide
(1.5 + Krf) nm
RFCF
Alert Area
(No Lower Limit)
RFCF Alert Envelope
RWY
RFCF Alert Envelope
0 1 2
Distance to Center of Runway (nm)
(Outer Limit)
TCF Alert Envelope
3 4 5 6
060-4241-000
Rev H, August 2011
5.0 nm
7