The Horizontal Situation Indicator

1
The Horizontal SituationIndicator

• Bendix/King
• KCS55A

2
Introduction

• Describe the 4 elements of the Horizontal
  Situation Indicator System
• Describe the Indicator Display
• Present the method of operation
• Describe the Failure Modes
• Present alternative method of operation

3
Objectives

• List the 4 elements of the HSI system
• Describe the HSI Display
• State the normal method of operation
• State the failure modes
• State the method of operation with degraded
  performance

4
Four Elements of HSI System
Display (Instrument Panel)
Directional Gyro (Behind Baggage Bay Bulkhead)
Magnetic Slaving Transmitter (Left Wingtip)
Slaving Meter / Compensator Unit (Instrument
Panel)
5
HSI Display
6
Slaving Meter/Compensator
Slaving Meter
Free Slave Gyro Switch
Clockwise Adjustment
Counter clockwise Adjustment
7
Slaving System Failure

• HSI does not agree with magnetic compass during
  normal flight (not aerobatics)
• Move free/slave gyro switch to free position
• Align HSI compass card with magnetic compass
  using CW/CCW switch.
• Operate as for normal DG system by regularly
  synchronizing HSI with Magnetic Compass.

8
Abnormal Operation

• Directional Gyro Mode
• Free / Slave switch in Free
• Use CW/CCW switch to synchronize with Magnetic
  Compass
• Fast Slave
• Switch Free / Slave switch from Slave to Free
  and back to Slave.

9
Summary

• The 4 elements of the Horizontal Situation
  Indicator System
• The Indicator Display
• Method of operation
• The Failure Modes
• Alternative method of operation

10
Questions

• List the 4 elements of the HSI system
• Describe the HSI Display
• State the normal method of operation
• State the failure modes
• State the method of operation with degraded
  performance