Honeywell International Inc. KSN770 用户手册

Page 3-61

6 Dec 2012

SYSTEM INSTALLATION MANUAL

066-01204 / 066-01213

© Honeywell International Inc. Do not copy without express permission of Honeywell.

For enroute/terminal operations, roll composite steering is the preferred method of coupling to a 
flight control system. If flight control coupling is made using course datum and D-bar and the KSN 
7xx cannot drive the course selector and the pilot will need to make manual course adjustments 
encountered in the flight plan. For the roll steering to function on the KSN 7xx a heading source 
must be connected to the KSN 7xx.

The pilot must be made aware of the problems that can occur if the course selector is not manually 
updated as with simple course deviation indicators and HSIs without remote course select. The 
flight control system will be able to remain on course (CDI centered) if the combination of both the 
selected course error and the current cross-wind correction does not exceed the autopilot’s 
cross-wind correction authority which is typically 30 degrees. Once the cross-wind correction 
authority limit of the autopilot has been reached the autopilot will begin to fly the CDI with a 
constant offset.

The size of the offset is proportional to the degree which the authority limit has been exceeded.

Any bank angle limiting of less than 25 degrees within the flight control system will cause 
overshooting of the waypoint due to the KSN 7xx turn anticipation algorithm assuming a 25 
degrees bank angle turn.

FCS LOCALIZER ENGAGE is used to make an interfaced flight control system track more 
appropriately when the KSN 7xx is in approach active mode. Hookup is required if 
autopilot-coupled GPS approaches will be flown using course datum and D-bar from the KSN 7xx.

For the roll steering to function on the KSN 7xx an ARINC 429 or XYZ heading source must be 
connected to the KSN 7xx.

NOTE: In the cases of the following ports, unused pins must be configured as “NONE” or “N” on 

the maintenance pages for proper operation. Open pins configured as being used will flag 
data and may generate failure messages:

J1-71

GPS GAMA 429 TX A

J1-51

GPS GAMA 429 TX B

This output is shared with the ARINC position interface. Refer to Paragraph 3.4.4 Electrical 
Characteristics for details.

Flight computer information is broadcast on this bus. The roll steering output is groundspeed 
scheduled. If there is no GPS groundspeed, 0 degree will be commanded by label 121, roll steering 
command. Post-installation checkout is facilitated by data output during self-test.

While the self-test page is displayed on the KSN 7xx, label 121 goes through the following cycle 
continuously:

NOTE: The output is 0 degree for 6 seconds, then ramps up to 5 degrees at 1 degree/sec. The 

output is then stable at 5 degrees for 6 seconds. The output then ramps down to 0 degree 
at 1 degree/sec.

Draft as of 10/15/2012