CIRRUS AIRPLANE MAINTENANCE MANUAL Rudder CHAPTER 55-40: RUDDER GENERAL 55-40: RUDDER 1. General The rudder provides airplane directional (yaw) control and includes a rudder trim tab used for yaw trim adjustment. The rudder is of conventional design with skin, spar and ribs manufactured of aluminum. The rudder is attached to the aft vertical stabilizer shear web at three hinge points and to the fuselage tailcone at the rudder control bellcrank. Rudder motion is transferred from conventional rudder pedals to the rudder by a single cable system under the cabin floor to the rudder sector pulley in the aft fuselage. A push-pull tube from the sector to the rudder bellcrank translates cable motion to the rudder. Springs connected to the rudder pedal assembly close the loop and provide centering force. 1
CHAPTER 55-40: RUDDER. Maintenance Practices CIRRUS AIRPLANE MAINTENANCE MANUAL A. Rudder Assembly (See Figure 55-40-1) (1) Removal - Rudder Assembly (a) (b) (c) (d) Remove cotter pin, nut, washers, and bolt securing rudder push/pull rod to rudder. Remove cotter pins from bolts securing rudder to vertical stabilizer. Remove lower bolt, washers, and castellated nut securing rudder to vertical stabilizer. While supporting rudder assembly, remove upper and center bolts, washers, and castellated nuts securing rudder assembly to vertical stabilizer. Remove rudder assembly from vertical stabilizer. () Disassembly - Rudder Assembly Rudder assembly may be further disassembled through removal of trim tab and rudder bottom. (a) Rudder Trim Tab 1 Acquire necessary parts, tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Drill bit #40 Any Source Drill out rivets. (b) Drill out rivets securing trim tab to rudder. Rudder Bottom 1 Remove screws securing rudder bottom to rudder.
CIRRUS AIRPLANE MAINTENANCE MANUAL CHAPTER 55-40: RUDDER () Assembly - Rudder Assembly (a) Rudder Trim Tab 1 Acquire necessary parts, tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Alodine Pen - Any Source Corrosion protection. (b) Using an Alodine pen, apply corrosion protection to edge of each rivet hole. Install rivets securing trim tab to rudder. 4 Apply thin coat of paint to each rivet head. (Refer to 51-0) 5 Perform Adjustment/Test - Rudder Balancing. (Refer to 55-40) Rudder Bottom 1 Position rudder bottom to rudder and install screws securing rudder bottom to rudder. (4) Installation - Rudder Assembly (a) (b) Verify threaded end of bolts are installed downward. Position rudder assembly to vertical stabilizer. Install bolts, washers, and new castellated nuts to upper and center hinges securing rudder assembly to vertical stabilizer. Torque bolts at upper and center hinges 0 to 5 in-lb (. to.8 Nm). (Refer to 0-60) Maximum of two washers are added between bottom hinge and rudder assembly to obtain proper clearance. (c) Install bolt, washers, and castellated nut to lower hinge securing rudder assembly to vertical stabilizer. (d) Torque bolt at lower hinge 50 to 70 in-lb (5.6 to 7.9 Nm). (Refer to 0-60) (e) Secure all bolts with new cotter pins. (f) Position rudder push/pull rod to rudder and secure with bolt, washers, nut, and new cotter pin. (g) Perform Inspection/Check - Rudder Gap and Overlap. (Refer to 55-40)
CHAPTER 55-40: RUDDER CIRRUS AIRPLANE MAINTENANCE MANUAL (h) Perform Inspection/Check - Rudder Assembly. (Refer to 55-40) (i) If rudder trim tab was replaced, perform Adjustment/Test - Rudder Trim Tab. (Refer to 55-40) (5) Inspection/Check - Rudder Assembly (a) Verify hinge bolts for proper torque and installation. (Refer to 0-60) (b) Verify proper installation of safety wire and cotter pins on all fasteners. (Refer to 0-50) (c) Ensure rudder skin is smooth and free of any defects or irregularities. (d) Inspect rivets and rudder skin for tightness. (e) Operate rudder controls and inspect for any abnormal resistance. 4
CIRRUS AIRPLANE MAINTENANCE MANUAL Figure 55-40-1: Rudder Assembly RUDDER HORN (REF) CHAPTER 55-40: RUDDER 1 VERTICAL STABILIZER (REF) 6 5 6 5 11 LEGEND 1. Lead Washer. Washer. Bolt 4. Washer, Large Area 5. Castellated Nut 6. Cotter Pin 7. Rudder 8. Rudder Bottom 9. Screw 10. Trim Tab 11. Rivet 1. Nutplate 1. Rod End NOTE 6 5 4 6 5 1 Maximum of two washers are added between bottom hinge and rudder assembly to obtain proper clearance. On replacement rudder bottom, verify marked locations for match drilling obtain the proper edge margin required for hole and nutplate installation. 9 10 7 8 11 1 SR_MM55_457 5
CHAPTER 55-40: RUDDER CIRRUS AIRPLANE MAINTENANCE MANUAL (6) Inspection/Check - Rudder Gap and Overlap (See Figure 55-40-) (a) Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Inclinometer PRO60 Macklanburg Duncan Deflection angle determination. (b) (c) (d) (e) (f) Adjust rudder to the fully leftmost position. CAUTION Allowable gap between rudder horn and vertical stabilizer is between 0.150 and 0.00 inch (.81 and 7.6 mm). At rudder horn, verify gap between rudder horn and vertical stabilizer is between 0.150 and 0.00 inch (.81 and 7.6 mm). If gap between rudder horn and vertical stabilizer does not fall within the specified clearance, contact Cirrus Design Customer Service Department for disposition. (Refer to AMM-Intro-00) Repeat gap measurement with rudder to the fully rightmost position. The following gap and overlap inspections need only be performed after the installation of a replacement (new or different) rudder or after repairing the lower rudder hinge. If rudder leading edge gap and overlap inspections do not fall within the specified clearances, contact Cirrus Design Customer Service Department for disposition. (Refer to AMM-Intro-00) Replacement Rudder Installation Only: Verify gap between rudder leading edge and trailing edge of vertical stabilizer has a minimum of 0.060 inch (1.54 mm) and a maximum of 0.50 inch (8.890 mm) clearance when rudder is fully deflected right and left. The rudder overlap inspection applies only to the area between the waterline of the horizontal stabilizer to the tip of the vertical stabilizer. Replacement Rudder Installation Only: Verify overlap between rudder and vertical stabilizer has a minimum of -0.15 inch (-.175 mm) and a maximum of 0.15 inch (.175 mm) clearance. Rudder may be deflected left 0 to 5 to achieve right overlap, and may be deflected right 0 to 5 to achieve left overlap. 6
CIRRUS AIRPLANE MAINTENANCE MANUAL CHAPTER 55-40: RUDDER Figure 55-40-: Rudder Gap and Overlap +5-5 NEUTRAL NOTE Verify gap between rudder horn and vertical stabilizer is between 0.150 and 0.00 (.81 and 7.6 mm). OVERLAP GAP INSPECTION Replacement Rudder Installation only: Verify leading edge gap has a minimum of 0.060 inch (1.54 mm) and a maximum of 0.50 inch (8.890 mm) clearance. Replacement Rudder Installation only: Measure tangent to the leading edge curvature. Replacement Rudder Installation only: Verify overlap gap has a minimum of -0.15 inch (-.175 mm) and a maximum of 0.15 inch (.175 mm) clearance. Replacement Rudder Installation only: Measure overlap tangent to the leading edge curvature. Use a 6 inch straight edge. 0.0 LEADING EDGE GAP INSPECTION SR_MM55_4574 7
CHAPTER 55-40: RUDDER CIRRUS AIRPLANE MAINTENANCE MANUAL (7) Adjustment/Test - Rudder Balancing (See Figure 55-40-) CAUTION When balancing, the rudder assembly must be complete including mounting brackets, paint, stripes, rudder bottom, and rudder tip. The bench used to support knife edge supports must be level. Maximum mass balance weight is.5 pounds (1.1 kg). (a) Acquire necessary tools and equipment. Description P/N or Spec. Supplier Purpose Close Tolerance Balance Pins - Any Source Support rudder assembly. Balance Fixture - Any Source Balance rudder assembly. Straight Edge - Any Source Mark chord line and hinge centerline. Grease Pencil - Any Source Make reference marks. (b) Remove rudder. (Refer to 55-40) (c) (d) (e) (f) (g) (h) The chord line is defined as the line extending from the trailing edge through the hinge line. This line runs perpendicular to the rudder spar. Using reference holes in rib, mark chord line on inboard rib shearweb. Place straight edge directly on center of each rivet head used to secure rudder skin to rudder spar (not hinge mount rivet heads). With straight edge in place, mark reference line to indicate rivet head centerline. Mark reference line 4.0 inches (10.16 cm) aft (towards trailing edge of rudder) of rivet head centerline mark previously made. This line must run parallel to centerline of all three hinges. Using rivet head centerline as a reference, mark reference line 0.75 inch (1.91 cm) forward (towards hinges). This reference line is referred to as the hinge centerline. The area between hinge centerline mark and line 4.0 inches (10.16 cm) aft of rivet head centerline is referred to as the balance zone. Place close tolerance balance pins into upper and lower hinge mounts. 8
CIRRUS AIRPLANE MAINTENANCE MANUAL CHAPTER 55-40: RUDDER (i) (j) (k) (l) (m) (n) (o) (p) (q) Level work bench (in all directions) using spirit level. Using rudder assembly as a temporary locator, place balancing fixtures into position on level work bench. Ensure each knife edge support is parallel to bench top by placing spirit level on each of the knife edge supports. If required, shim base of knife edge support fixtures to ensure that knife edges are parallel to bench top. Ensure balance arm is parallel to bench top by placing spirit level on balance arm. If required, shim base of balance arm to ensure balance arm is parallel to bench top. If chord line mark is parallel to balance arm without any additional weight, rudder assembly is balanced. If balance arm and chord line mark can be made parallel by placing a 10 ounce (0.8 kg) weight on or within the balance zone reference lines, rudder assembly is balanced. No further action is necessary. Carefully place rudder assembly onto knife edge supports and determine if a static overbalance (leading edge heavy) or static underbalance (trailing edge heavy) condition exists. To balance rudder that is under balanced (trailing edge heavy), proceed to the following steps. CAUTION When balancing, the rudder assembly must be complete including mounting brackets, paint, stripes, rudder bottom, and rudder tip. The bench used to support knife edge supports must be level. Maximum mass balance weight is.5 pounds (1.1 kg). 1 Place weight directly above the lead washer mount in the rudder horn until the chord line and balance arm marks are parallel. Remove safety wire and lead washer mounting bolts along with all balance material. Place all required balance material into position and secure lead washer mounting bolts. 4 Safety wire lead washer mounting bolts. (Refer to 0-50) To balance a rudder that is over balanced (leading edge heavy), proceed with the following steps. 9
CHAPTER 55-40: RUDDER CIRRUS AIRPLANE MAINTENANCE MANUAL CAUTION When balancing, the rudder assembly must be complete including mounting brackets, paint, stripes, rudder bottom, and rudder tip. The bench used to support knife edge supports must be level. Maximum mass balance weight is.5 pounds (1.1 kg). 1 Remove balance material from lead washer mounting bolts as required to achieve alignment of chord line to balance arm. Place all required balance material into position and secure lead washer mounting bolts. Safety wire lead washer mounting bolts. (Refer to 0-50) (r) Install rudder. (Refer to 55-40) (s) Operate rudder and inspect for proper operation. 10
CIRRUS AIRPLANE MAINTENANCE MANUAL CHAPTER 55-40: RUDDER Figure 55-40-: Rudder Balancing (1 of ) CHORD LINE RIB SPAR 1 RIVET HEAD CENTER LINE HINGE CENTER LINE AFT LIMIT LINE.75" 4" LEGEND 1. Rudder. Balance Pin. Reference Hole 4. Rivet Head (Skin to Spar) TRAILING EDGE NOTE Do not place straight edge over hinge mount rivet heads. SR_MM55_4575 11
CHAPTER 55-40: RUDDER CIRRUS AIRPLANE MAINTENANCE MANUAL Figure 55-40-: Rudder Balancing ( of ) SR_MM55_4576 1
CIRRUS AIRPLANE MAINTENANCE MANUAL CHAPTER 55-40: RUDDER Figure 55-40-: Rudder Balancing ( of ) BALANCE ZONE 1 CHORD LINE NOTE Temporarily place weight at this location until chord line and balance arm are parallel to each other (underbalanced rudder). LEGEND 1. 10 oz. Weight SR_MM55_4577 1
CHAPTER 55-40: RUDDER CIRRUS AIRPLANE MAINTENANCE MANUAL (8) Adjustment/Test - Rudder Trim Tab WARNING Maintenance check flight must be performed by a licensed pilot. Both fuel tanks must contain equal amounts of fuel. Do not bend trailing edge of rudder trim tab right more than 5 or left more than 10. (a) (b) (c) (d) After airplane is in flight and clear of all traffic, turbulence, and wake, at altitude between 4,000 and 6,000 MSL, set throttle to 75% power. Allow airplane time to accelerate and stabilize at cruise speed. It is recommended to use the autopilot in HDG and ALT hold modes during this procedure. Aileron input will be maintained as needed to hold constant heading but will apply no rudder input. Trim ailerons and elevator for steady heading level flight and release any rudder pressure. Observe and note the deflection of the ball inclinometer; the ball should be centered. Support trim tab at the bend when adjusting to ensure trim tab does not bend at the rivets and pull away from rudder. If required, bend rudder trim tab in small increments (approximately 1 to ) in opposite direction as ball deflection and repeat maintenance check flight. 14