|Object Name:||Three Axis Trim Indicator|
|Division:||Eclipse-Pioneer [of Bendix]|
|Year of Manufacture:||circa 1968|
Ref No 6TK13
Indicator - Three-Axis Trim
S.A.E. Spec AS 402 TSO-C98
Rating 1-0-1 volts 1000 ohms per volt approx.
Wt. Lbs. 1
Serial No. 6011130
The Bendix Corporation
Teterboro, New Jersey
Made in USA
Converted from Bendiix Type 15101-1F-A5 to Elliott Type 4559-A-1.
Weston Elec. Inst. Corp., U.S.A.
The Three-Axis Trim Indicator has a dual function to display trim conditions.:
• To display any commands held in the system in the form of a signal applied to the torque motors prior to the Autopilot engagement.
• To show “feel out-of-trim condition of the aircraft while under Autopilot control.
The top window on the Indicator displays the status of the Rudder;’ left rudder’ has the central bar to the left of the two fixed bars and ‘right rudder’ the converse.
The middle window gives the Aileron status; if the central bar is tipped down to the left that indicates the aircraft is in a ‘left bank’ and conversely.
The bottom window gives the Elevator status; if the central bar is above the fixed bars that is ‘up elevator’ and conversely if the bar is below the fixed bars it indicates ‘down elevator’.
Before the Autopilot is engaged the Trim Indicator should be approximately at the zero position for each display. Any displacement is proportional to the surface movement that would result should the Autopilot be engaged. With the Yaw Damper in operation the Aileron and Elevator indications should remain at the zero position. Corrective action to the Rudder will however show up on the Indicator but any constant deflection is due to the setting of the manual trim controls.
In the VC10 Automatic Flight Control System the two Autopilots are equipped with separate, but identical sets of indicators and warning lamps to keep the pilots visually informed of operating and fault conditions. These items are located on the respective pilot’s instrument panels and are:
• Three-axis Trim Indicator to display trim conditions.
• Autopilot Press-to-Teat warning lamp to indicate system failure.
• Autothrottle warning lamp to indicate airspeed signal errors and Autothrottle failure.
• Glideslope Arming Indicator lamp and Glideslope Engaged indicator lamp.
• Autotrim monitor lamp.
• Triple Yaw Damper Indicator
The unit was made under licence from Bendix and was converted from Bendiix Pt No. 15101-1F-A5. Weston Elec Inst Corp U.S.A. Model 1883, Type 104 (This was used in the Autopilot Trim Position Indicator, Type O-2, for the USAF Autopilot Type E-4 (aka as the Sperry A-12 Gyrosyn Automatic Pilot System). The E-4 System was used in the late 1940-1950's and was still in use in some 1960's aircraft. Lockheed C-130 Hercules and C-121 Constellation transports used this system)