ENGINE GOVERNOR INSTALLATION
The engine governor reduces pilot workload and increases flight safety by constantly monitoring engine speed and adjusting the throttle to maintain a set engine RPM. It will not serve as an automatic pilot. As with any aircraft system, the attention of the pilot is required throughout all phases of flight.
The system consists of a throttle actuator, control unit, status indicator light, assorted switches and an engine RPM sending unit. It is powered via a 5 amp circuit breaker which supplies power to the control unit, which in turn powers the other system components. The governor utilizes two of the switches included in the Collective Switch Box Kit, which is packaged separately. Instructions for installing the switch box are included in this section.
An engine RPM signal is developed using either a magneto mounted sensor or the digital tachometer output of an electronic ignition system and fed to the control unit. The control unit is set to maintain an engine speed of 492 RPM +/- 1%.
The system includes an electronic clutch which can be manually overridden by the pilot in the event of a system failure. The system also has an Increase/Decrease switch which allows the pilot to adjust the engine speed to an RPM that is slightly higher or lower than the factory default. This temporary adjustment is cleared once the governor is powered down and the system reverts back to the default factory setting.
Everything required to install the engine governor is included in the Engine Governor Kit and the Collective Switch Box Kit.
Using the schematic provided in this manual, perform a pin to pin check of the 8 pin connector harness provided in the Governor Kit. Pin 1 is identified by a small dot next to the pin. Subsequent pins are counted going in a circular direction away from the key-way of the connector. Pin 8 is in the center.
Check that you have the correct sensor input (3 pin connector harness) for your ignition system.
With electronic ignitions the 3 pin connector has one shielded wire for connection to the ignition control unit.
With magneto ignitions the 3 pin connector will have a magneto vent hole sensor attached to it. Be sure we have sent you the correct sensor. T1A9-1 is for Slick magnetos. T1A9-2 is for Bendix magnetos.
INSTALLING THE SERVO MOTOR
The servo motor is an electronic stepper motor that moves the throttle linkage in response to signals from the control unit. These inputs are generated in pulses and their intensity is regulated by the control unit. This acts to serve as an electronic clutch. The intensity of the pulses is set at the factory to a preset level of over-ride torque that is compatible with most SAFARI throttle controls. Should you find that you are unable to over-ride the servo motor or that it does not effectively move the controls, please contact the factory.
If the main battery is connected, remove and isolate the connections to prevent accidental contact.
Install the servo motor into the motor mount using the four small socket head cap screws included in the Governor Kit. The motor only fits one way in the mount. Safety wire the screws.
Install the servo motor arm to the motor drive shaft using the two remaining fillister screws. The arm should be mounted at a 90° angle to the top edge of the motor case. Safety wire the screws.
Use a marker to indicate 5/16” from the end of the shaft of the two rod ends. When the installation is complete, at least 5/16” of the shaft must be in the connecting rod.
Thread the two AN316-4R pal nuts onto the shaft of the two rod ends up to the shoulder of the rod end. Install the rod ends into the throttle linkage to the face of the pal nuts. As you settle the governor assembly into position and make adjustments to it after flight testing, you may need to lengthen or shorten the servo linkage. If so, ensure that the rod ends have at least 5/16” of threads remaining in the connecting rod, not counting those in the nut. Any adjustments should be evenly distributed between the rod ends on each end of the connecting rod. After adjusting the rod end, the pal nut should be tightened against the end of the connecting rod.
Temporarily position the motor mount/motor assembly on the collective pivot tube and use hose clamps to keep it in position while you attach the throttle linkage.
Loosely install the throttle linkage to the servo motor arm and co-pilot's upper throttle bell crank, using AN4-12 bolts, AN960-416 washers under the bolt heads and AN970-4 washers between the rod ends and the AN310-4 nuts. Be certain the large washer is used in this position. In the event of failure of the rotating center of the rod end, the large washer will hold the rod end captive and allow some level of control.
The lateral position of the servo motor on the collective pivot tube is determined by positioning the mount so that both the co-pilot's upper throttle bell crank and the servo bell crank arm are pointing straight up.
Rotate the motor mount on the collective pivot tube to align the bell cranks and linkage fore and aft.
Check to be sure that there is no interference or binding in the throttle linkage through the full range of motion of the collective and the throttle. Use washers to move the linkage off the servo arm if needed.
When the motor and linkage are in the proper position, tighten one hose clamp. Move the other screw clamp out of the way, and use a set punch to mark the location for the motor mount bolt. Position the bolt about midway in the tabs that overhang the motor mount.
On the side not clamped securely, carefully drill straight through the motor mount and collective pivot tube at the marked locations. Take care to keep the drill aligned so that the hole is centered through the collective pivot tube on both sides of the tube.
Secure the motor mount to the pivot tube using an AN4-14 bolt (2) AN960-416 washers and an AN320-4 nut. Torque and cotter pin the nuts using AN380-2-2 pins.
Repeat the process on the other side of the mount,
Tighten the throttle linkage bolts. Torque and cotter pin the nuts using AN380-2-2 pins.
INSTALLING THE CONTROL BOX
The control unit receives input signals from the ignition system and sends outputs to the servo motor to constantly adjust the throttle positioning to maintain a fixed engine RPM. The control units are configured at the factory depending on the ignition system in use. The preferred input method is from an electronic ignition source as it provides a clean, high-resolution signal to the controller. Inputs from the ignition system are evaluated and compared to the set point that is calibrated into the controller. Corresponding motor control impulses are generated and sent to the servo motor to adjust the engine RPM.
By use of the Increase/Decrease function, the set RPM can be altered slightly to improve performance in varying conditions. This feature does not allow operation outside of the pre-set limits. This adjustment is also temporary and defaults back to the factory setting once the governor is powered off.
Using the holes in the mounting flanges of the control box as a guide, mark and drill 1/8” pilot holes in the governor mounting plates welded onto the cabin frame.
Install nut plates in the four locations and secure the control box to the mounting plates using 8-32 stainless steel screws included in the Governor Kit. Position the box with the three plugs on the lower side of the box.
WIRING THE GOVERNOR
The control unit has three circular electrical connectors which interface it to the controls, signal inputs and servo motor. The 4 pin connector contains the wiring for the servo motor. The 3 pin connector is for the signal input, and the 8 pin connector is for power, ground and control inputs.
These connectors are intended to be environmentally resistant but care should be taken to prevent contamination by water, solvents and other liquids. All three connectors are keyed to ensure the proper pin to pin connections and have locking rings that make them resistant to vibrations.
The picture below illustrates the suggested routing of the wiring. To prevent possible interference in the signal wires, keep them away from high voltage sources such as spark plug wires and electronic ignition coils and wires. Interference between electronic components could result in un-commanded inputs to the governor system and must be eliminated prior to aircraft operation.
The current configuration of the SAFARI governor allows for only the pilot to control the governor. All wiring for the control switches is run into the pilot's collective stick and the switches are located in the pilot's collective switch box.
WARNING
The SAFARI governor system has been tested to be electronically compatible with the SAFARI cyclic trim system. Any other engine speed monitoring or control systems should be checked for proper operation and compatibility.
Plug the male end of the 4 pin connector into the control box. This is the receptacle closest to the pilot’s side.
Route the wires along the frame up to the collective pivot tube. Leave a loop of 1-1/2” to 2” to allow for movement of the controls. Route the wire along the pivot tube toward the motor.
Plug the female end of the harness into the connector on the servo motor.
Plug the 8 pin connector into the control box. Route the wires down and toward the front of the frame. At the entry point of the console, separate the I, D, and / wires and route them toward the pilot’s collective stick. These wires will be installed in the collective switch box.
Route the L, +, and - wires toward the instrument panel, center console, and aircraft ground respectively.
Solder the L wire to Terminal 2 of the Press-To-Test/caution light in the instrument panel. (If you had the necessary soldering done by an outside provider, you will already have a wire that you need to connect to the L wire with a butt connector)
Terminal 1 should already be soldered to the instrument power wire, and Terminal 3 should already be soldered to the ground wire exiting the instrument panel.
Trim and connect the + wire to the LOAD side of the PILOT ASSIST breaker in the console.
Trim and connect the - wire to the common ground on the solenoid board.
WARNING
The GOV caution light is an integral part of the governor system. It provides critical information to the pilot regarding the status of the governor system. Without the GOV light, the pilot is unaware of the governor status and may incorrectly assume that the governor is in control of the throttle when in fact, it is not. This is a serious condition that could result in severe damage to the aircraft, serious injury or death.
CAUTION
Failure to ensure that the governor switches are connected to anything other than aircraft common ground could result in damage to equipment or unexpected operations of associated components. Some components such as relay coils, solenoids and light bulbs may read continuity to ground when in fact the meter is reading through the wires in the coil or across the filament wire in the bulb.
INSTALLING THE COLLECTIVE SWITCH BOX
From the Control Kit, locate one of the two rubber collective grips. Cut the closed end off the rubber grip about midway of the enlarged end and slide it on the pilot’s collective past the retaining collar. Position the switch box with the mounting holes over the retaining collar, with the surface slightly rotated toward the pilot’s seat. Using a punch or a very small drill bit, make a small divot in the retaining collar at both of the set screw locations. Be careful not to damage the threads in the set screw holes. If you prefer, you can use a pressure transfer material on the end of the set screws to identify where they will contact the retaining collar.
The confines of the box must be identified before cutting the face plate to size. Lay the box face down on a piece of thin paper and mark the outline of the box. Cut out the template, turn the box over, and put the template on the face of the box. Using chalk or the flat edge of a pencil, mark the locations of the face plate screw holes and the inside edge of the box. Position this template on the rectangular face plate provided. Be sure that each of the switches identified on the face plate will fall within the confines of the inside of the box. When satisfied with the placement, use a scribe to mark the positions of the face plate screws and the outside shape. Cut the face plate to shape and smooth the edges. Drill the screw locations with a #27 drill bit. Install the switches on the face plate. The “ears” on the rocker switch can be spread apart slightly to remove the plastic actuator from the switch body. Press it back onto the “ears” to secure it. Next, locate the starter button wire - from the solenoid wiring bundle of the wiring harness. Route it toward the pilot’s collective. If you have ordered avionics with your kit, including a transceiver wiring harness, the radio “flip-flop/mem” button wire is included. Locate this wire and route it toward the pilot’s collective. If you have not ordered avionics, cut a 6’ length of 22 gauge wire and identify it as “radio” on both ends. If you are not installing avionics, take the time to install this wire in the switch box for future use. Coil and terminate the unused wire at the rear of the console. From the governor wiring harness, locate the wires I, D and /. Route them toward the pilot’s collective. Cut a 6-1/2’ piece of 20 gauge wire and mark it as “G” on both ends. Tape the ends of the 5 wires together, and push them through a 2” length of shrink tubing. Then push them through a 24” length of 3/8” OD insulating sleeve. You will want to seal the end of the insulating sleeve with shrink tubing, and it can’t be put on after the wires are connected. Beginning at the starter button, connect the common ground “G” to one side of all switches (Common(C)), with the exception of the governor rocker switch. Connect the ground wire to the center post of this switch.
Connect the - wire to the other side of the starter switch (NO). Connect the I wire to the Increase side of the governor rocker switch, and the D wire to the Decrease side of the rocker switch. The contact that closes when the switch is pushed forward will be for the INCR and the I wire should be installed on this side. Connect the / wire to the remaining post of the governor on/off switch. Tie the wire bundle close to the entrance to the collective stick. Slide the insulating sleeve forward of the tie on the bundle and tie it off forward of the tie securing the bundle together. Attach the black probe of an ohm meter to the ground wire to be sure that the only wire in the switch box with continuity to ground is the (G) wire (common). Leave the black probe attached to the ground wire, and check the other switches for continuity. Remove the starter relay wire from the relay on the solenoid board, and attach the red probe to the starter wire. Press the starter button, and observe the reading on the meter. Plug the starter relay wire back in. Remove the 8 pin connector from the governor control box, and verify that the increase/decrease function and the on/off function of the governor are correct by attaching the red probe to the appropriate pin in the connector as identified by the schematic, and operating the switch. If all switches are functional, secure the box to the collective using the set screws provided. Install the set screws with a liquid thread locker to be sure they remain tight. Install the face plate on the switch box. This is a very tight space, so be careful not to damage your connections as you position the wires in the box. Leave 5-6” of the insulating sleeve extending past the end of the collective. Slide the short length of shrink tubing over the end of the insulating sleeve, and heat it to size.
TACHOMETER SIGNAL INPUT
The governor system retrieves a tachometer signal from the engine in order to determine its speed. This signal most often comes from the ignition system. The SAFARI governor has been developed to utilize signal from either a magneto ignition system or most electronic ignition systems. The control unit must be set to operate from the specific system at the factory. If you change the signal source from magneto to electronic or vice- versa, the control unit must be configured to reflect the new signal source.
MAGNETO IGNITION SIGNAL WIRING
Most magneto ignition systems use some method to alter the engine timing during the start sequence. This is accomplished by either using a second set of points tied to a secondary
ignition coil or via an impulse coupling which advances the timing mechanically during engine start. Typically, only one of the two magnetos will have these provisions and it is the one selected during engine start. We will be working with the magneto that DOES NOT have these provisions. It will be the one that is NOT selected during engine start and will be referred to as the Non-Starting magneto. If both of your magnetos have these provision, please contact the company for additional guidance. These procedures will require removal and re-installation of the Non-Starting magneto and it will require re-timing after it is re-installed. Checking the timing of the magnetos is beyond the scope of this manual.
Label and disconnect the magneto P-lead and plug wire cap from the Non-Starting magneto.
Remove the magneto from the engine accessory case and remove the vent hole cover. The vent hole is on the opposite side of the magneto from the inspection hole used to look at timing gear marks. It is usually inboard.
The signal input sensor has been wired into the 3 pin connector at the factory. Install it in the magneto vent hole and finger tighten plus 1/6 turn (one flat). Do not over-tighten.
Reinstall and check the timing of the magnetos.
Reconnect the P-lead wire and plug wire cap to the magneto.
Route the signal harness forward and through the firewall at the opening in the lower center of the firewall panel and upwards along the airframe to the governor control box. Plug the harness into the 3 pin connector on the box. Leave any excess wire in a loop near the firewall opening to prevent fluids from traveling along the harness into the box.
ELECTRONIC IGNITION SIGNAL WIRING
Most electronic ignition systems provide an electronic tachometer signal for use by aircraft instrumentation and systems. This signal output will be utilized by the governor system to determine engine speed. The harness supplied with the kit should reach and be compatible with most electronic ignition systems. If you find that this is not the case, please contact the factory for the proper harness. Some connections will require soldering. In those cases, make sure the connection is good and clean. Remove any flux residue from all soldered connections to prevent corrosion and signal degradation.
The SAFARI governor system is designed to be compatible with the following systems:
Light Speed Engineering - Plasma II, II+ and III E-Mag Air - E-mag and P-Mag Slick/Unison - LASAR
Compatibility with other systems should be confirmed with Safari before proceeding.
Connect the signal input harness to the 3 pin connector on the control unit.
Route the harness along the aircraft frame to the electronic ignition controller.
Trim the harness to remove any excess slack and install the center conductor in the appropriate pin on the electronic ignition controller:
E-Mag - Pin 6 (terminate the shield, it has no connection on this end) Plasma II, II+, and III - Input connector Pin 6 (shield to pin 13) LASAR - Brown Wire (terminate the shield, it has no connection on this end)
SYSTEM CHECKS
GOVERNOR SELF-TEST
Pull the Mixture Control Full Out.
Place the throttle at about mid position.
Turn on the MASTER, INSTRUMENT circuit breakers. The GOV light should
illuminate.
Press to Test the GOV light. The GOV light should illuminate.
Turn on the PILOT ASSIST (or applicable) circuit breaker. The GOV Light should remain on.
Press the GOV switch to ON. The GOV Light should remain on. Depress and hold the INCR/DECR switch in the INCR direction. After a few seconds, the GOV light will flash.
Switch the INCR/DECR switch to DECR. The GOV light comes on steady.
Press and hold the INCR/DECR switch in the INCR direction and hold it until the GOV light begins to flash. The throttle should move first to increase power then decrease and cycle several times. The GOV light will flash rapidly when the test is done.
Check that the governor servo clutch is engaged.
The throttle should have noticeable resistance but can be over-ridden. Over-ride force should allow the pilot to manually command the throttle if needed and must be correct Over-ride force is adjusted internally and can only be accomplished by the factory.
Press the GOV switch to OFF. Return Mixture to normal position.
FLIGHT TEST WARNING
Un-commanded inputs to the throttle system may be possible. Ensure the pilot can over-ride the governor if needed and monitor the controls at all times. Only a qualified pilot should accomplish these procedures.
Ensure the aircraft is ready for flight.
Perform a self test of the governor.
Follow normal engine start procedures, and engage the applicable circuit breaker and turn on the GOV switch once the engine and transmission have warmed up. The GOV light will flash.
Slowly advance the throttle. At some point, the GOV light will flash rapidly and the governor will take control of the throttle and slowly increase RPM to flight speed.
Maintain a close eye on the throttle and disengage the governor if it appears it may overspeed. Once the engine is at flight speed the GOV light will go out.
Press the INCR switch. RPM will increase slightly.
Press the DECR switch. RPM will decrease back to its original speed.
Guard the throttle and press the GOV switch OFF. The GOV light comes on and the governor releases the throttle.
Check that the servo clutch has released.
Press the GOV switch ON. Increase collective slightly. The governor will command the throttle to maintain RPM.
Return collective to the lower stop and perform an engine shutdown.
CAUTION The first 5 hours of operation with the new governor installation should be accomplished in a testing environment to ensure there are no unexpected occurrences. The pilot in command of the aircraft should maintain control of the throttle and other flight controls at all times during all phases of aircraft operation.
GOVERNOR CONNECTORS PIN MAP