Technical data

Product Specification
HIF-2121/R5 CAGE CODE: 97896 SCALE: NONE SIZE: A DWG NO: 965-1176-601 REV: D SHEET 17
0 400 800 1200 1600 2000 2400 2800
UNSAFE TERRAIN CLEARANCE
RADIO ALTITUDE (FT)
M
IN
T
E
R
R
A
IN
C
LE
A
R
A
N
C
E
(F
T
)
3000
2800
2600
2400
2200
2000
1800
1600
1400
1200
1000
800
600
400
200
0
GEAR UP, FLAPS UP
TAKE-OFF OVER FLAT TERRAIN
OR WATER
1500 FPM CLIMB RATE
WARNING AREA
WARNING AREA (>200 KTS)
"TOO LOW TERRAIN"
"TOO LOW TERRAIN"
M
ODE 4C UNSAFE TERRAIN
CLEARANCE
(<168 KTS)
FIGURE 1.3.1.4-5: MODE 4C - UNSAFE TERRAIN CLEARANCE - AT TAKEOFF (TURBOPROP)
0 400 800 1200 1600 2000 2400 2800
UNSAFE TERRAIN CLEARANCE
RADIO ALTITUDE (FT)
M
IN
T
E
R
R
A
IN
C
LE
A
R
A
N
C
E
(F
T
)
3000
2800
2600
2400
2200
2000
1800
1600
1400
1200
1000
800
600
400
200
0
GEAR UP, FLAPS UP
TAKE-OFF OVER FLAT TERRAIN
OR WATER
1500 FPM CLIMB RATE
WARNING AREA
WARNING AREA (>250 KTS)
"TOO LOW TERRAIN"
"TOO LOW TERRAIN"
MODE 4C UNSAFE TERRAIN
CLEARANCE
(<190 KTS)
FIGURE 1.3.1.4-6: MODE 4C - UNSAFE TERRAIN CLEARANCE - AT TAKEOFF (TURBOFAN)
Optional variations to the Mode 4 alert boundaries are available through Envelope Modulation, as described in section
1.3.1.7. When Terrain Awareness is enabled, the Mode 4 A/B “Too Low Terrain” voice is limited to values below the “Too
Low Flaps” voice.
1.3.1.5 Mode 5 - Below Glideslope
Mode 5 provides two levels of alerting when the aircraft flight path descends below the glideslope beam on front course ILS
approaches. The first alert activation occurs whenever the aircraft is more than 1.3 dots below the beam and is called a “soft”
glideslope alert because the volume level of the “Glideslope” alert is approximately one half (-6 dB) that of the other alerts. A
second alert boundary occurs below 300 feet radio altitude with greater than 2 dots deviation and is called “loud” or “hard”
glideslope alert because the volume level is increased to that of the other alerts. Mode 5 is illustrated in Figure 1.3.1.5-1.