Textron Aviation Cessna 172S NAV III Skyhawk SP, Информационное руководство

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SECTION 9 - SUPPLEMENTS CESSNA
SUPPLEMENT 3 MODEL 172S NAV III
KAP 140 AUTOPILOT
U.S.
FAA APPROVED
NORMAL PROCEDURES
(Continued)
GPS NAV AND ROLL STEERING
The KAP 140 autopilot has DC (analog) roll steering capability. Roll
steering enables the flight guidance system (in this case, the G1000
GPS navigation computer) to control the autopilot through automatic
course changes at flight plan waypoints and to lock on to the course to
the next waypoint.
The GPS navigation computer uses ground speed, track and turn rate
data to calculate the bank angle required for waypoint course changes.
The GPS roll steering signal will make the autopilot turn the airplane
and lock on course to the next waypoint without flying directly over the
current waypoint, except for designated fly-over waypoints. The flight
path is approximately tangent to the inbound and outbound flight plan
legs.
The distance from the waypoint to start the turn will vary with
groundspeed, degrees of heading change, etc., but will usually be
approximately 0.5 nautical mile from the waypoint. Flight plan
sequencing to the next waypoint will occur at approximately the
midpoint of the turn.
Roll steering works only if all the following conditions are true:
1. GPS must be the navigation source shown on the G1000 HSI.
2. The GPS navigation computer must be executing an active flight
plan.
3. The KAP 140 must be engaged in NAV or APR mode.
4. The GPS must not be operating in OBS mode (PFD).
NOTE
When on an active GPS flight plan with the KAP 140
autopilot coupled in NAV or APR mode, waypoint course
changes greater than approximately 140° could result in a
turn rate that reaches the autopilot bank angle limit. The
pilot may need to change the KAP 140 to HDG mode (also
arm NAV or APR mode) and manually set the intercept
heading to help the autopilot lock on the new course.
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172SPHAUS-S3-01
S3-34
For
Training
Purposes
Only