CIRRUS AIRPLANE MAINTENANCE MANUAL

Transcription

1 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. Page 1 01 May 01

2 . MAINTENANCE PRACTICES A. Rudder Assembly (See Figure 1) (1) Removal - Rudder Assembly (a) Remove cotter pin, nut, washers, and bolt securing rudder push/pull rod to rudder. (b) Remove cotter pins from bolts securing rudder to vertical stabilizer. (c) Remove lower bolt, washers, and castellated nut securing rudder to vertical stabilizer. (d) 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. Drill out rivets securing trim tab to rudder. (b) Rudder Bottom 1 Remove screws securing rudder bottom to 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) (c) 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 ) Rudder Bottom 1 Position rudder bottom to rudder and install screws securing rudder bottom to rudder. Serials 1005 thru 1541: Rudder Bottom Replacement 1 Acquire necessary parts, tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Permanent Marker - Any Source Mark Drill bit inch (0.485 cm) Any Source Match Drill Position rudder bottom to rudder and ensure gap is equal to or less than 0.5 inch (1.7 cm). Verify reveal line between rudder bottom and rudder are consistent along Page

3 length of seam, and trailing edge of rudder bottom is flush with trailing edge of rudder. CAUTION: Verify marked locations for match drilling obtain the proper edge margin required for hole and nutplate installation. Use marker to mark match drill locations in rudder bottom. 4 Using inch (0.485 cm) drill bit, drill at marked locations on rudder bottom. 5 Install rivets and nutplates at drilled hole locations on rudder bottom inboard flange. 6 Apply thin coat of paint to each rivet head. (Refer to 51-0) 7 Install screws securing rudder bottom to rudder. (4) Installation - Rudder Assembly Verify threaded end of bolts are installed downward. (a) (b) 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 to 0-5 in-lb (. -.8 Nm). 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) Tighten bolt at lower hinge to in-lb ( Nm). (e) Secure all bolts with cotter pins. (f) Position rudder push/pull rod to rudder and secure with bolt, washers, nut, and cotter pin. (g) Perform Inspection/Check - Rudder Gap and Overlap. (Refer to ) (h) Perform Inspection/Check - Rudder Assembly. (Refer to ) (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 ) (b) Verify proper installation of safety wire and cotter pins on all fasteners. (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. Page 15 Dec 014

4 RUDDER HORN (REF) 1 VERTICAL STABILIZER (REF) 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 Page 4 NOTE 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. Figure 1 Rudder Assembly 11 1 SR0_MM55_180C

5 (6) Inspection/Check - Rudder Gap and Overlap (See Figure ) (a) Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Inclinometer PRO60 Macklanburg Duncan Deflection angle determination. Oklahoma City, OK (b) Adjust rudder to the fully left-most position. CAUTION: owable gap between rudder horn and vertical stabilizer is between and 0.00 inch (.81 and 7.6 mm). (c) At rudder horn, verify gap between rudder horn and vertical stabilizer is between 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. (d) Repeat gap measurement with rudder to the fully right-most 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. (e) Replacement Rudder Installation Only: Verify gap between rudder leading edge and trailing edge of vertical stabilizer has a minimum of 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. (f) Replacement Rudder Installation Only: Verify overlap between rudder and vertical stabilizer has a minimum of inch (-.175 mm) and a maximum of 0.15 inch (.175 mm) clearance. Rudder may be deflected left 0-5 to achieve right overlap, and may be deflected right 0-5 to achieve left overlap. Page 5

6 NEUTRAL NOTE Verify gap between rudder horn and vertical stabilizer is between and 0.00 (.81 and 7.6 mm). Replacement Rudder Installation only: Verify leading edge gap has a minimum of 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 inch (-.175 mm) and a maximum of 0.15 inch (.175 mm) clearance. 5 Replacement Rudder Installation only: Measure overlap tangent to the leading edge curvature. Use a 6 inch straight edge OVERLAP GAP INSPECTION LEADING EDGE GAP INSPECTION 1 SR0_MM55_087A Page 6 Figure Rudder Gap and Overlap

7 (7) Adjustment/Test - Rudder Balancing (See Figure ) 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 ) 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. (c) (d) (e) (f) (g) Using reference holes in rib, mark chord line on inboard rib shear web. 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. (h) (i) (j) (k) (l) (m) (n) Place close tolerance balance pins into upper and lower hinge mounts. 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. Page 7

8 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. (o) (p) 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). (q) 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. 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 ) (s) Operate rudder and inspect for proper operation. Page 8

9 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 Figure Rudder Balancing (Sheet 1 of ) NOTE Do not place straight edge over hinge mount rivet heads. SR0_MM55_196 Page 9

10 SR0_MM55_197 Page 10 Figure Rudder Balancing (Sheet of )

11 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 oz. Weight SR0_MM55_198 Figure Rudder Balancing (Sheet of ) Page 11

12 (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) 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. ow 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. (b) (c) 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. (d) If required, bend rudder trim tab in small increments (approximately 1 - ) in opposite direction as ball deflection and repeat maintenance check flight. Page 1