Lateral Gain Programming; Localizer/Back Course (Bc) Track; True Airspeed (Tas) Gain Programming - Honeywell PRIMUS 1000 Pilot's Manual

When the LBS trips, the flight director commands a turn toward the
desired VOR radial or runway at the optimum point 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 the specified
minimum. The minimum beam sensor trip point for the VOR mode is
±30 mV (» 1/2 dot). In the LOC mode, the minimum trip point is ±60 mV.
(» 2/3 dot) The maximum LBS trip point is ±175 mV (» 2 1/3 dots) for
VOR and ±195 mV (» 2 1/2 dots) for LOC.

Lateral Gain Programming

Lateral gain programming is used in both the VOR and localizer modes
of operation. In the VOR mode, gain programming is computed as a
function of DME distance to the station (if available) and TAS. This
adjusts for the aircraft moving toward or away from the station.
In the localizer mode, gain programming is required to adjust for the
aircraft closing on the localizer antenna and beam convergence caused
by the directional properties of the localizer antenna. In the localizer
mode, lateral gain programming is controlled by the change in radio
altitude (RA) with the aircraft below 2400 feet RA when the RA is valid.
If the RA is not valid, then gain programming starts as a function of the
localizer beam capture, TAS, and time.

Localizer/Back Course (BC) Track

Localizer and BC track signifies that the aircraft is on beam center and
crosswind correction can take place. The track phase occurs when the
following conditions are satisfied:
LOC or BC is captured plus 30 seconds
D
Localizer beam rate is less than 30 feet/second
D
Localizer beam deviation is less than 20 mV
D
Aircraft bank angle is less than 6° .
D

True Airspeed (TAS) Gain Programming

TAS gain programming is used to program heading select/track error,
course select error, PITCH wheel command, air data commands, and
glideslope deviation to maintain the same aircraft response regardless
of the aircraft' s airspeed and altitude. The TAS computation is derived
from airspeed and altitude.
A28--1146--112--00
PRIMUSr1000 Integrated Avionics System
System Limits
7-3