Lateral Beam Sensor (Lbs); Loc Cap 1 And Bc Cap 2; Loc Cap 2 And Bc Cap 2 - Honeywell SPZ-8000 Pilot's Manual

Lateral Beam Sensor (LBS)

When flying to intercept the VOR or LOC beam, the LBS is tripped as
a function of beam deviation, course error, TAS, and DME. In the LOC
mode, the course error is compared with the beam deviation signal and
rate of crossing the beam to determine the LBS trip point. When the LBS
trips, the flight director commands a turn toward the VOR radial or
runway to capture the beam. If the intercept angle to the beam center
is very shallow, the LBS does not trip until the aircraft is near beam
center. For this reason, an override on the LBS occurs when the beam
deviation reaches a specified minimum. The minimum beam sensor trip
point for the VOR mode is 1/4 dot. In the LOC mode, the minimum trip
point is 1/2 dot. The maximum LBS trip points are 2--1/2 dots for VOR
and 2--2/3 dots for LOC.

LOC CAP 1 and BC CAP 2

Localizer and back course capture 1 are the initial capture phases of
their respective modes. Localizer capture 1 and back course capture 1
occur when the following conditions are satisfied:
LOC armed plus 3 seconds
D
Either of the following occurs:
D
— LBS has been tripped
— Beam deviation is less than 1/2 dot.

LOC CAP 2 and BC CAP 2

Localizer and back course capture 2 are capture phases that indicate
the aircraft is flying closer to the center of the beam. The capture 2
phase occurs for each mode when the following conditions are all
satisfied:
LOC CAP 1 plus 3 seconds
D
Course error less than 35_
D
Beam deviation less than 1--1/2 dots.
D
A28--1146--055
REV 2
SPZ--8000 Digital Integrated Flight Control System
System Limits
7-3