Alpha Unmanned Systems ALPHA 800, Aircraft Maintenance Manual, Page: 23 / 143

COMMERCIAL IN CONFIDENCE
DEV ‐ M ‐ MM A800 V1.7
MAINTENANCE MANUAL
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Note: All UAV Maintenance documentation is designed to supplement the training given on Alpha Unmanned Systems'
comprehensive UAV Operator Course. UAV Maintenance must only be carried out by persons qualified on that Course; failure to
comply may invalidate the UAV warranty and may lead to accidents. For further information and the latest updates contact
info@AlphaUnmannedSystems.com .
Sheet # 005 Title TAIL PITCH SERVO REPLACEMENT
Applies to UAVs ALPHA 800
Special Tools Required Ball link pliers. User Tools with Internal Pilot.
Time (approx.) 30 mins
Introduction
Yaw control in helicopter type UAVs is achieved by varying tail blade pitch, controlled by the tail pitch
servo. It is vital that this servo is working correctly and that it is calibrated. Without this, the autopilot will
not be able to control yaw, resulting in poor flight performance or an accident. Depending on the UAV,
the tail pitch servo may be mounted on the main chassis and connected via a control rod which runs the
entire length of the tail tube (010164106) (e.g. COMMANDO, SNIPER LE), or it may be mounted directly
at the tail rotor casing (e.g. ALPHA 800).
Step by Step Procedure
Step 1 ‐ Disconnect the Tail pushrod (010164134) using the
correct tool (e.g. ball link pliers).
Step 2 ‐ Unplug the servo from the Power and Communications
Module (PCM) (010139111) by unscrewing the connector and
remove any cables ties used to secure the cable.