SAFARI Helicopter Flight Control Rigging Manual Revision 9 4/3/2010 CHR International Inc. The following procedures are meant as a guide to assist you in the safe configuration of your helicopter s Flight Control Rigging. Throughout this guide it is assumed that the operator is working with materials supplied by CHR. We do not advise the use of components obtained from other manufacturers as we have not confirmed that those component qualities are compatible with the aircraft. It is recommended that you read and understand all the steps related to a procedure as well as any CAUTION or WARNING statements before starting it to prevent injury or damage to components. The following conventions are used in these procedures to identify steps or situations in which failure to follow procedures could result in injury or damage to equipment. CAUTION A CAUTION statement will precede any step in which failure to follow specific directions could cause damage to equipment or minor injury to the operator. WARNING A WARNING statement will precede any step in which failure to follow specific directions could cause catastrophic failure of equipment, serious injury or death. All procedures listed are critical in nature and should be read and understood by the operator prior to attempting. The absence of a CAUTION or WARNING statement does not infer that a given step in the procedure is of less importance. As the manufacturer of the aircraft, it is the builder s responsibility to ensure the safety of pilot and passengers. The construction prints offer detailed pictures of the cabin flight control linkage in drawings 13 through 17. 1. Cyclic Pitch Rigging...2 2. Cyclic Roll Rigging...3 3. Swash Plate Rigging...3 4. Collective / Throttle Rigging...5 5. Tail Rotor Rigging...7
1. Cyclic Pitch Rigging a. Level the helicopter on all axes by measuring from the Main Rotor pylon mount or mast tube. b. Lock collective full down. c. Install rod ends in cyclic pitch horn and base of Pilot s cyclic NOTE: New rod ends can be very tight. To loosen them up, place a long bolt through the ball and, using washers to shim it up, tighten a nut down to the washers. Get a cup of water handy to cool the parts. Tighten the bolt into the chuck of your drill and spin the ball with the drill until you feel the drag lessen. Quickly cool the parts in the water. You want the rod end to rotate freely, but no side to side play. Repeat as required. i. Remove the rod ends d. Center the Pilot s cyclic stick vertically and horizontally as measured with an angle finder or protractor NOTE: If the cyclic lock will not hold the stick centered left-right and fore-aft, it should be modified so that it does to improve ground operations at idle and to make rigging easier. e. Position the Pilot s side cabin pitch horn so that it is vertical. f. Measure the length of ½ x.083 aluminum tubing required to connect the two rod ends with at lest 80% of the threads in the tube. i. This is usually around 22. ii. They can always be shortened if too long. g. Cut the tubes to the required length and square the ends. i. Thread the tube ends with a 3/8 N.F. tap. h. Install rod ends with jam nuts in tubing i. Install the control rod. j. Adjust the control rod at both ends until the cyclic stick and pitch horn are vertical. i. At least twice the diameter of the rod ends should be threaded into the rod (3/4 ). ii. If not, a new rod must be made. k. Repeat steps f through j for the Co-pilot s side. l. Adjust control rod at both ends until cyclic sticks are parallel fore-aft. Page 2 of 8
2. Cyclic Roll Rigging a. Center cyclic sticks horizontally and vertically b. Install rod ends in roll bell cranks. c. Measure the length of ½ x.083 aluminum tubing required to connect the two rod ends with at lest 80% of the threads in the tube. i. Remove the rod ends d. Cut the tubes to the required length and square the ends. i. These are usually about 17 e. Thread the tube ends with a 3/8 N.F. tap. f. Install rod ends with jam nuts in tubing. g. Install the control rod. h. Adjust the control rod at both ends until both sticks are parallel in the leftright axis. i. At least twice the diameter of the rod ends should be threaded into the rod (3/4 ). ii. If not, a new rod must be made. 3. Swash Plate Rigging a. Ensure the helicopter is level on all axes by measuring at the Main Rotor pylon or mast tube. NOTE: When working above the clutch assembly it is recommended that the fan guards are installed to prevent foreign objects from falling into the fan area. A work platform can also be installed to make working around the gearbox more practical. b. Install the Main Rotor push-pull rods between the cabin controls and lower swash plate. c. Ensure the cyclic stick is centered and the collective stick locked down. d. Adjust left and right control rods to obtain 2 5/8 inches between the bottom of the upper swash plate (rotating part) and the Main Rotor pylon. Page 3 of 8
i. The swash plate should be level left-right. e. Adjust pitch control rod (center) until the upper swash plate is level foreaft. f. Unlock collective and pull full up until the distance between the upper swash and the Main Rotor pylon is 1 5/8 i. Adjust collective pivot stop bolts on either side of control beam. g. Unlock and position cyclic full left while watching for binding of the swash plate controls. i. Swash plate shows at least 7 degrees off level with no binding h. Position the cyclic full right while watching for binding of the swash plate controls. i. Swash plate shows at least 7 degree off level with no binding. i. Position cyclic full forward while watching for binding of the swash plate controls Page 4 of 8
i. Swash plate shows at least 7 degrees off level with no binding j. Position the cyclic full aft while watching for binding of the swash plate controls. i. Swash plate shows at least 7 degrees off level with no binding. k. Lock the collective full down. l. Repeat steps h through k. m. Adjust cyclic lateral stops so that swash plate can tilt 9 degrees in either direction. n. Adjust cyclic forward stop so that swash plate can tilt 12 degree forward. o. Adjust cyclic aft stop so that swash plate can tilt 9 degrees aft. p. Ensure main push-pull rods have at least twice the diameter of the rod end threaded into the rod. q. Tighten jam nuts at all rod ends and stops. r. Tighten and cotter pin all rod end bolts 4. Collective / Throttle Rigging NOTE: Increased throttle correlation can be obtained by extending the bolt between the collective throttle horn and the forward upper throttle control rod end. The longer the bolt is, the greater the ratio of throttle to collective will be. Use a standoff as a spacer. This can result in less throttle manipulation by the operator when moving the collective. You may need to twist the collective throttle horn and rotate the rod end to ensure clearance between the seat brace. a. Remove the carburetor throttle arm and rotate counterclockwise. i. While it is off, drill the center hole of the 3 out to ¼ b. Reinstall the arm so that when the carburetor stop is at idle, the arm is angled down and forward roughly 25 degrees. i. As a reference, straight down is 0 degrees. ii. All further adjustments are made with the carburetor stop at idle. c. Install nut and cotter pin. d. Install rod ends in the center hole on the carburetor control arm and aft throttle control arm. e. Measure the length of ½ x.083 aluminum tubing required to connect the two rod ends with at lest 80% of the threads in the tube so that lower control arm is angled down 45 degrees from level and facing the pilot s side. i. This is usually 10 ¼ f. Remove the rod ends g. Cut the tube to the required length and square the ends. i. Thread the tube ends with a 3/8 N.F. tap. Page 5 of 8
ii. Install rod ends with jam nuts in tubing. h. Install the control rod. WARNING When installing a rod end to one side of a control arm, it MUST be held on the other side by a penny washer (AN970-4) with the bolt head on the washer side. If possible, the bolt should be installed from the front of the aircraft with the nut on the aft side. In the event that the ball separates from the rod end, the penny washer will hold it captive and allow partial control authority. Otherwise, the rod end is permitted to fall off the control arm and all control authority is lost. i. Adjust control rod so that carburetor control arm is on the idle stop and aft control arm is 25 degrees down from level and facing the pilot s side. j. Install rod ends in the forward throttle control arm and collective throttle control horn. k. Measure the length of ½ x.083 aluminum tubing required to connect the two rod ends with at lest 80% of the threads in the tube so collective control horn is angled 45 degrees down and pointing outboard. i. This is usually 7 l. Remove the rod ends m. Cut the tube to the required length and square the ends. i. Thread the tube ends with a 3/8 N.F. tap. ii. Install rod ends with jam nuts in tubing. n. Install the control rod. i. On the upper rod end it may be necessary to install the bolt on the aft side of the horn to provide clearance for collective movement. o. Adjust control rod so that collective throttle control horn is angled down 45 degrees. p. Set collective grips so that both horns point up i. On the co-pilot s side, one should point outboard and one should point up. Page 6 of 8
q. Install rod ends in the two vertical horns r. Measure the length of ½ x.083 aluminum tubing required to connect the two rod ends with at lest 80% of the threads in the tube. s. Remove the rod ends t. Cut the tube to the required length and square the ends. i. This is usually about 17 u. Thread the tube ends with a 3/8 N.F. tap. i. Install rod ends with jam nuts in tubing ii. Install the control rod. v. Adjust the control rod so that both horns are exactly vertical. i. Check that the throttle will open and close completely when collective is full down. w. Raise collective about 25 degree and check again x. Raise collective full up y. Rotate grip so that throttle is opened fully and slowly lower collective. i. Keeping the grip rotated, observe throttle linkage and controls for interferences with other fixtures. ii. At full down, ensure grip can be rotated to close throttle. z. Set throttle stop bolt at base of the pilot s collective so that no force is exerted on the carburetor shaft but throttle is full open. i. Tighten all jam nuts and cotter pin all nuts. 5. Tail Rotor Rigging NOTE: The push-pull cable should be routed along the outside of the tail boom lower longeron to keep it as straight as possible. Any bends should be kept to a minimum. a. Install aft end of cable assembly in the frame with the locator nuts loose. b. Ensure rubber boot is in position and install NyLoc nut then rod end i. Rod end must be threaded on at least twice the diameter of the shaft. (Or to pin hole in rod end) c. Rotate tail rotor swash plate fully counter clockwise (out) i. Pull cable out its entire length d. Adjust locator nuts and rod end so that rod end will reach past swash arm hole by 1/16 Page 7 of 8
e. Push cable in as far as possible and rotate swash plate clockwise (in) fully. i. The rod end should travel past the swash plate arm hole slightly. f. Install rod end to swash plate arm with bolt, penny washer, stainless steel lock washers and nut. g. Align pedals and adjust walking beam rod ends to achieve a comfortable position in relation to your leg length. i. Pedals should be tilted slightly forward and centered. ii. Walking beam grease nipple should point up. iii. Co-pilot s left pedal should connect to lower walking beam arm and pilot s right pedal should connect to upper walking beam arm. h. Install push-pull cable with rod end and locator nuts loose. i. Push cable fully in then pull it out 1 and center rudder pedals. j. Adjust locator nuts and rod end so that rod end is aligned with the hole in the pedal tab. i. Bolt should slide through rod end and tab freely. ii. Bolt rod end to pedal tab with bolt, penny washer and nut. 1. A few washers and a longer bolt may be required to align the rod end parallel to the pedal tab. k. Push right pedal and adjust the stop to limit travel by 1/8 short of full. l. Push left pedal and adjust the stop to limit travel by 1/8 short of full. m. Tighten all jam nuts and cotter pin all nuts. Page 8 of 8