Robinson Maintenance Manual

left (helicopter-right) magneto. Starting assist for O-320-A2C, O-320-B2C, and O-360- J2A engines is provided by a starter vibrator system and retard points in the engine-left magneto. Tachometer points in the engine-right magneto supply engine RPM information to the governor controller and engine tachometer. At 104% engine tachometer indication the engine is turning 2652 RPM. Induction is through an air filter located in a carburetor-mounted air box assembly. Carburetor heat is supplied by an exhaust-pipe-mounted scoop and duct. Carburetor heat is controlled through a cable-operated guillotine valve in air box. Carburetor inlet air is filtered, even with carburetor heat on. Provision for an obstructed air filter is provided by a spring loaded bypass valve mounted on the air box cover, or by air box flexing. On Beta II/Mariner II aircraft, application of carburetor heat is correlated with changes in collective setting through a friction clutch to reduce pilot work load. Lowering collective mechanically adds carburetor heat and raising collective reduces carburetor heat. The pilot may override the friction clutch and increase or decrease carburetor heat as desired. A latch is provided at the carburetor heat control knob to lock carburetor heat off when not required. Cooling is supplied by an engine-mounted fanwheel enclosed by a fiberglass scroll. The scroll ducts cooling air to engine-mounted panels which in turn direct air to cylinders, external oil cooler, alternator, and main rotor gearbox. Power is transmitted through a vertically mounted sheave-and-belt system which is engaged by an electric belt tension actuator. Battery charging and electrical power is supplied by 60-amp belt-driven alternator. A 70- amp alternator is optional. ROBINSON MAINTENANCE MANUAL R22 SERIES Page 6.2 Chapter 6 Powerplant OCT 2014 6.100 Powerplant NOTE Refer to engine and engine component manufacturer mainte- nance publications for product specific inspection, repair, and maintenance procedures. 6.110 Engine Removal NOTE If engine is to be removed to facilitate a lower frame replacement, engine mount change, or firewall repair, fanwheel can remain installed. However, if engine is to be disassembled, remove fanwheel per § 6.210. 1. Disconnect static line from and remove aft cowling, tailcone fairing, B429-5 frame. NOTE If aux tank installed, defuel helicopter. Remove aux tank. 2. Disconnect main rotor gearbox cooling duct and remove horizontal firewall access panel (aft right-hand). 3. Remove clutch assembly per § 7.210. 4. Remove side skirts. Turn off fuel selector valve and disconnect fuel hose at carburetor. Cap fuel hose and carburetor inlet port. 5. Disconnect carburetor throttle linkage at carburetor bellcrank, mixture control cable at carburetor, carburetor heat control at air box, and carburetor air temperature probe at quick-disconnect, located approximately four inches from probe in a heat shrink sleeve. Remove carburetor and air box assembly. NOTE Air box and carburetor may be removed as a unit. 6. Disconnect oil pressure hose from elbow on accessory housing and cap exposed connections. 7. Disconnect manifold pressure line from forward, left cylinder fitting and clamp and cap exposed connections. 8. Identify for reinstallation and disconnect engine ground straps, alternator leads, starter leads, oil pressure line, cylinder head temperature lead, and oil temperature lead. Disconnect all clamps attaching wiring to steel tubular frames. Disconnect belt tension actuator motor leads. 9. Disconnect cabin heater duct, if installed (optional equipment). 10. Disconnect primer line, if installed (optional equipment). ROBINSON MAINTENANCE MANUAL R22 SERIES ROBINSON MAINTENANCE MANUAL 6.110 Engine Removal (cont'd) HOIST PROTECTIVE PADDING DIRECTION OF ENGINE REMOVAL FIGURE 6-1 POWERPLANT REMOVAL Change 26: APR 2007 MCCEL R22 6.3 ROBINSON MAINTENANCE MANUAL MODEL R22 6.4 6. 110 Engine Removal (cont'd) 11. Install protective padding per Figure 6-1. 12. Connect MT016-1 "C" fitting to a minimum 500-pound capacity hoist and to engine lifting lug per Figure 6-1. Take up any slack in chain or cable of hoist. Engine mounting pads have shims placed between pads and engine mounts for proper engine alignment. Note shim stack for each mount and record for re installation. 13. Remove four engine mounting bolts. This will require removal of right-side (engine -left) spark plug access cover. 14. Place a support stand under tail skid or remove tailcone. 1 5. Remove tubular steel strut at right rear corner of steel tube structure. With a person on each side of engine, carefully remove engine. Vary height of engine as required to clear aft cross tube during removal. Swing engine clear of helicopter. Refer to Figure 6-1 . 6. 120 Engine Installation a) Connect MT016-1 "C" fitting to a minimum 500-pound capacity hoist and to engine lifting lug per Figure 6-1. Carefully hoist engine and swing it into alignment with engine mounting pads. b) Select appropriate shims as recorded during engine removal. If no record is available, install a 0.063-inch thick shim between both lower mounting pads and engine and install a 0.190-inch thick shim between both upper mounting pads and engine. Install engine mounting bolts, torque per Section 1.320. Torque stripe per Figure 2-1. Install right rear tubular strut per Section 4.222 h). WARNING Damage or failure of drive line components may result from incorrect engine shimming. c) Disconnect engine hoist, install horizontal firewall, right-hand spark plug access panel, and aft cowling. Reconnect main rotor gearbox cooling duct. d) Install carburetor using a new gasket and torque nuts per Section 1 .330. Install palnuts, torque per Section 1 .320, and torque stripe per Figure 2-1. Change 26: APR 2007 6.120 Engine Installation (cont’d) e) Reconnect throttle linkage to middle position of carburetor bellcrank. Refer to § 10.150 for throttle rigging. Reconnect mixture control and carburetor heat control and rig these controls for 1/16” springback at each end of the control travel (See Chapter 10 for rigging of throttle). f) Reconnect engine grounding strap and torque engine oil sump bolts per § 23-33. Connect oil line to oil pressure sender. Connect manifold pressure line to engine and firewall connections. g) Reconnect all electrical leads to oil temperature sender, cylinder head temperature sender, alternator, magnetos, etc. h) Install cabin heater ducting and all wire and oil line clamp connections. i) Connect fuel line to carburetor and inspect engine compartment for proper installation of all electrical connections, control attachment, ducting and routing. j) Reinstall clutch assembly. (See § 7.200). k) Reinstall engine access panels, compartment panels and aft cowling. I) Before running engine, check following components for proper alignment: 1) Sheave alignment per § 7.230. 2) Tail rotor drive shaft shimming per § 7.330. 3) Cooling shroud-to-tailcone clearance 0.250 inch minimum. 4) Intermediate flex plate to tail rotor bellcrank clearance 0.250 inch minimum with belts over 10 hours, 0.125 inch minimum with new belts. 5) Clutch shaft angle per § 7.240. 6) Upper sheave centering per § 7.250. NOTE Fill engine to proper oil level. NOV 2020 Chapter 6 Powerplant Page 6.5 ROBINSON MAINTENANCE MANUAL R22 SERIES 6.130 Engine Shimming To facilitate sheave proper alignment, the engine must be shimmed to 3.55/3.75 inches, measured between ring gear top and bottom of upper frame’s long cross tube with clutch engaged. 1. Engage clutch. 2. Measure ring gear-to-upper frame cross tube dimension as shown in Figure 6-2. If dimension exceeds 3.75 inches, an equal amount of shims must be added between lower frames and both the lower-left and the lower-right engine rubber mount pads. Use following formula to calculate required maximum shim thickness: (Measured ring gear-to-upper frame dimension) – 3.55 = Calculated shim thickness 2 Select shim(s) as required up to, but not exceeding, calculated shim thickness. Shims are available in thicknesses of 0.032 inch, 0.063 inch, and 0.190 inch. Removing an equal amount of shims from between both lower frames and the lower-left and the lower-right engine rubber mount pads will increase ring gear-to-upper frame cross tube dimension. 3. Disengage clutch. 4. Remove side skirts. 5. Loosen upper-left and lower-left engine mount bolts. Leaving right engine mounts torqued, install selected shim(s) between lower-left frame and lower-left engine mount pad. Slotted shims, if used, may be stacked together but must be installed between unslotted shims and safetied. See Figure 6-2A. 6. Torque engine-mount bolts per § 23-32. 7. Remove right-side spark plug inspection panel. Loosen upper-right and lower-right engine mount bolts. Leaving left engine mounts torqued, install selected shim(s) between lower-right frame and lower-right engine mount pad. 8. Torque engine-mount bolts per § 23-32. 9. Engage clutch. Verify ring gear-to-upper frame cross tube dimension as shown in Figure 6-2. Adjust as required. 10. Torque stripe nuts per Figure 2-1. Page 6.6 Chapter 6 Powerplant NOV 2020 ROBINSON MAINTENANCE MANUAL R22 SERIES NOV 2020 Chapter 6 Powerplant Page 6.7 FIGURE 6-2 ENGINE INSTALLATION ROBINSON MAINTENANCE MANUAL Shim washers (Minimum one A 141-25 adjacent to rubber mount) nLower frame \ A 141-12 Washer (1 Req'd) R22 SERIES Mount bolt L:JEngine Rubber mount pads Spacer Washers as required to maintain 2-4 threads protruding from nut. Add shim washers A141-12 (0.190 inch), A141-24 (0.032 inch), B155 (0.032 inch), A 141-25 (0.063 inch) as required to shim engine. B155 shims, if used, shall be be- tween A 141 washers (ref. Figure 6-2A). 3 . 55-3. 75 inches I Engine ring gear I I I ~ ~ 1 As an alternative to a scale, locally 0 ! 1 fabricate a go/no-go gage from rigid : sheet metal. Gage should measure 0 1 3.55 x 3. 75 inches with a 2-inch diameter hole in the center. Page 6.8 Chapter 6 Powerplant NOV 2020 NOTE Engine mounting shims added or subtracted at two botttom engine mounts will change engine ring-gear-to-frame dimension by approximately twice the thickness of engine mount shim. Example: Adding a 0.032-inch thick shim at each bottom engine mount will raise rear of engine approximately 0.064 inch. FIGURE 6-2A B155 ENGINE SHIM ROBINSON MAINTENANCE MANUAL R22 SERIES B155-2 Shim (0.032 in.) Snaps in place ; no cotter pin or safety wire required. B155-1 Shim (0.032 in.) B155 Shim(s) must be installed between two A 141 shims X Minimum A141-12 or -25 shim adjacent to rubber mount ~ I I ~ Install cotter pin or safety wire ~ after ;nstallafon. NOV 2024 Chapter 6 Powerplant Page 6.9 6.130 Engine Shimming (continued) NOTE AN6- engine mount bolts are obsolete and must be replaced with NAS1306- or NAS6606- series bolts when shimming engine. 11. Check clutch sheave alignment per § 7.230. 12. Reinstall engine inspection covers and side skirts. 13. Adjust throttle correlation rigging per § 10.150. ROBINSON MAINTENANCE MANUAL R22 SERIES Page 6.10 Chapter 6 Powerplant NOV 2024 FIGURE 6-3A FAN HUB ACCESS AND LOWER BEARING BRACKET ALIGNMENT FIGURE 6-3B PULLING FANWHEEL ROBINSON MAINTENANCE MANUAL R22 SERIES FAN HUB BOLT ACCESS '-- MT091-1 Engine ring gear holder Mark edge of fanwheel----,------.. adjacent to split line of scroll. MT092-1 Fanwheel Puller "' ~ ,@ Insert screwdriver into bracket notch ~ ~'\__ .::.. ~~ Q artially inserted bolt BEARING BRACKET ALIGNMENT Engine ring gear support at magneto timing position . NOV 2024 Chapter 6 Powerplant Page 6.11 6.200 Cooling System 6.210 Fanwheel Removal CAUTION Do not engage clutch actuator without scroll installed. NOTE If same fanwheel is to be reinstalled then orient starter ring gear support to magneto timing position and mark fanwheel at split line of scroll; this will minimize need for new balance weights. See Figure 6-3B. 1. Ensure clutch actuator is fully disengaged. Pull out CLUTCH START (5 or 7.5 amp) circuit breaker and turn battery switch off. 2. If installed, loosen clamp securing cabin-heater hose to lower scroll half and disconnect hose. 3. Remove scroll-to-engine cooling panel perimeter screws and two bolts attaching scroll to A181-4 bearing. 4. Cut safety wire and remove spring pin from fanwheel retaining nut. Remove retaining nut. Remove washers. Install retaining nut 3 full turns to prevent fanwheel from dropping while being removed. 5. Refer to Figure 6-3B. Install MT092-3 spacers directly on each of (3) long B660-1 bolts (if installed; nuts remain in place). Alternately, remove scroll lower half then replace every other nut & washer (3 each) with MT092-3 spacers. 6. Back out MT092-1 fanwheel puller’s center bolt, lubricate bolt tip & threads with A257-9 anti-seize, and attach puller to MT092-3 spacers. 7. Secure MT091-1 engine ring gear holding tool to ring gear support. Immobilize tool so ring gear remains stationary. NOTE Fanwheel may come off tapered shaft with a loud pop. 8. Tighten fanwheel puller’s large center bolt against fanshaft until fanwheel is unseated. 9. Remove fanwheel puller. Apply B270-21 protectant to exposed B660-1 bolt threads. If nuts were removed, apply wet primer to mating surface of fanwheel and install washers & nuts on fanwheel hub bolts. While primer is wet, special torque nuts per § 23-33 and torque stripe per Figure 2-1. 10. Remove fanwheel retaining nut. Remove fanwheel and scroll. ROBINSON MAINTENANCE MANUAL R22 SERIES Page 6.12 Chapter 6 Powerplant NOV 2024 6.220 Fanwheel Installation CAUTION Beta II/Mariner II helicopters must use B174-1 Rev F (12 NAS6603-6 cone-to-fanwheel attach bolts) or subsequent fanwheels and A007-5 or -6 (111/16 inch nut) or subsequent shaft assemblies. 1. Evaluate drive belts, alternator belt, and A181 bearing condition; replace as required. Clean tapered shaft and fanwheel hub mating surfaces with approved solvent and dry. Inspect shaft and hub for damage; replace as required. 2. If removed, place scroll upper half on fanwheel and install fanwheel on tapered shaft. Secure scroll upper half to engine cooling panels. 3. Using A257-9 anti-seize, coat threaded portion only of A007 shaft and clamping surfaces of MS20002-18 washer & NAS1149F1832P washers (as many as needed to install spring pin), and castellated nut. Install hardware with MS20002-18 washer against hub. NOTE If installing original fanwheel ensure starter ring gear support is at magneto timing position and align marks on fanwheel with scroll split line. 4. Secure MT091-1 ring gear holding tool to ring gear support and hold ring gear stationary. Special torque fanwheel retaining nut per § 23-33 until slot in castellated nut aligns with hole in fanshaft. Install spring pin and safety with 0.041-inch diameter stainless steel wire (may be installed after dynamic balance per § 6.240). NOTE If slot in castellated nut does not align with hole in fanshaft throughout torque range, remove or add NAS1149F1832P washers (or AN960 washers) under nut. 5. Verify (6) fanwheel hub bolts are properly torqued per § 23-33. Apply torque stripe per Figure 2-1 after dynamic balance per § 6.240. 6. Refer to Figure 6-3A. Install lower cooling scroll half (if removed). Insert two AN3 bolts through lower bracket and actuator bearing block until they enter upper bracket nut plates. If required, align upper bracket nutplate by inserting screwdriver in bracket notch. Standard torque bolts per § 23-32 and torque stripe per Figure 2-1. 7. If revision I or prior fanwheel was replaced by revision J or subsequent fanwheel, and lower scroll was not replaced, contact RHC Technical Support for D229-4 cover relocation instructions. ROBINSON MAINTENANCE MANUAL R22 SERIES NOV 2024 Chapter 6 Powerplant Page 6.13 6.220 Fanwheel Installation (continued) 8. Install screws, nuts and washers around scroll perimeter, verify security. 9. Mark fanwheel with torque seal directly opposite each end of fanwheel nut spring pin to allow detection of movement between fanwheel and fan shaft. 10. Pull fanwheel aft to take-up crankshaft and crankcase front end clearance (ref Lycoming SSP-1776). Verify B229 lip-to-fanwheel inlet clearance is 0.060 ± 0.030 inch. If necessary, lip clearance may be adjusted by elongating lip mounting holes. 11. Dynamic balance per § 6.240. CAUTION Fanwheel balance must be checked upon installation; fanwheel imbalance can cause damage. Fanwheel retaining nut must be retorqued after first engine run. 6.230 Reserved ROBINSON MAINTENANCE MANUAL R22 SERIES FIGURE 6-4 FANWHEEL DYNAMIC BALANCE Page 6.14 Chapter 6 Powerplant NOV 2024 ROBINSON MAINTENANCE MANUAL R22 SERIES stall brackets using . existing hardware . S~cure all cables --- =-.--- \ uct tape ~ ,-~---'•,.. - · '/ "Photocell " • . \ y Photocell bracket l.~, -- - :--,\ ,::-:: A 181-4 Bearing assembly - ... --.... , I ' I \ I \ I I \ I \ I ' , ' I ... __ _ ...... . ::- ,:.. I , ..... , I I I' , I •- Balancer Add weight by increasing washer size opposite accelerometer /velocimeter. Alternatively, remove weight by decreasing washer size adjacent to accelerometer/velocimeter. Do Not Remove NAS6603-6 bolts. NAS 1149F0363P Washer = 0 . 03-0 . 05 IPS Change A 141-17 Washer = 0.08-0. 10 IPS Change AN970-3 Washer = 0 . 18-0 . 20 IPS Change Mix above sizes as required for balance . Ensure 2-4 threads exposed beyond nut. Radius R = 5. 10 inches on revision "J" and subsequent fanwheels ; R = 4.10 inches on revision "I" and prior fanwheels. .. ft Bolt Two acceleromet , • I _, I velocimeter brackets bolted together. Accelerometer I velocimeter cable Accelerometer I velocimeter/ 7 sensitivity axis , Light 1-------.... , side 6.240 Fanwheel Dynamic Balance NOTE The following instructions pertain to Chadwick-Helmuth Vibrex™ 2000 series. When using MicroVib, Chadwick-Helmuth Model 177- or 8350- series, or equivalent equipment consult the equipment’s specific operating instructions. 1. Clean fanwheel including fan vanes using mild soap (pH between 7 & 9) and warm water solution. Rinse thoroughly with potable water. 2. Refer to Figure 6-4. Install accelerometer on lower actuator bearing left bolt. Accelerometer wire should be pointed down. A suitable bracket may be assembled from two accelerometer brackets or may be fabricated. 3. Install photocell nearest to 12 o'clock position using existing hardware in upper scroll half. Secure cables to scroll assembly with duct tape. 4. Place C701-1 or 907-4270-1 target tape at one fan vane edge. 5. Connect cables to balancer, turn balancer power on. 6. Ground run helicopter at 104% with rotor system engaged. WARNING Use extreme care near tail rotor. 7. Select appropriate channel. Wait until engine stabilizes at approximately 2652 RPM, then press start. 8. Note vibration reading & clock angle displayed on balancer. 9. Shut down engine. CAUTION Ensure ignition switch is off and keys are out of switch whenever fanwheel is moved by hand. 10. As required, following first run-up after fanwheel installation, secure MT091-1 ring gear holding tool to engine ring gear support and hold stationary. Special torque AN320-18 nut per § 23-33 until spring pin can be installed in shaft. Install spring pin and safety with 0.041-inch diameter stainless steel wire. NOTE If spring pin cannot be installed within AN320-18 nut’s torque range, remove or add NAS1149F1832P washers under nut. Large pliers may be used to squeeze spring pin into position. NOV 2024 Chapter 6 Powerplant Page 6.15 ROBINSON MAINTENANCE MANUAL R22 SERIES 6.240 Fanwheel Dynamic Balance (continued) 11. As required, following first run-up after fanwheel installation, verify (6) fanwheel hub bolts are properly torqued per § 23-33. 12. If IPS exceeds 0.2, balance weights must be changed. Rotate fanwheel until target tape is in position noted in step 8. Increase balance weight by changing washers under nut closest to 1 o'clock position or by splitting required weight change among two nearest nuts per Figure 6-4. Alternatively, weight may be decreased under nut closest to 7 o'clock position. Total washers under each nut must result in (2) to (4) threads protruding past nut to ensure proper clamp-up. Access balance weight bolt heads thru hole under D229-4 cover (if installed; cover may be retrofitted using P/N Kl-111 Kit) on forward side of lower scroll or thru oil cooler access door (with a crowfoot on a flex handle) and rotating fanwheel as required. Ensure NAS1149F0316P washers (if installed) are not dislodged if NAS6603-6 bolts are removed. Special torque NAS6603 bolts per § 23-33. Install D229-4 cover. 13. Recheck fanwheel balance and adjust as required to obtain less than 0.2 IPS. 14. Remove balancing equipment from helicopter. 15. Torque stripe fasteners per Figure 2-1 as required. Page 6.16 Chapter 6 Powerplant NOV 2024 ROBINSON MAINTENANCE MANUAL R22 SERIES ROBINSON MAINTENANCE MANUAL MO □ ELR22 6.250 Cooling Scroll Replacement a) Remove the old scroll halves and actuator assembly, if installed. b) Level the airframe laterally per Section 1.210. Assemble the A 185-1 bracket on the bottom of the bearing housing with the A 185-2 on the upper left and the A 185-5 on the upper right. Use two AN3-41 A bolts to secure the brackets {See Figure 6- 5A). Place a bubble level across the top surface of the lower actuator bearing. Rotate the housing to level the bearing. c) Place the upper scroll half {A236-1) and the engine cooling fan on the fanshaft. Do not disturb the position of the lower actuator bearing. Finger tighten the fanshaft nut. On Beta and Mariner ships with the larger oil coolers, the right-hand side of the upper scroll sits on the oil cooler ledge. Adjust the upper half laterally to center the lip of the fan and the edge of the inlet scoop, then clamp to the sheet metal shrouds {See Figure 6-5B). d) Install the lower scroll half {A236-3) to the upper. Check the clearance between the lip of the fan and the edge of the inlet scoop. The clearance should be concentric all the way around the lip of the fan. Adjust both the halves as required and clamp into position (See Figure 6-5B). e} Carefully mark the position of the lower actuator bearing and brackets on the scroll halves. Mark the mounting holes on the scroll halves through the sheet metal shrouds. Mark the top and sides of the scroll at the edge of the sheet metal shrouds. Using a 90 degree angle drill, with a #18 drill bit, match drill as many mounting holes as possible. Cleco clamp or install AN525-832 screws to secure the scroll as the holes are drilled. Match drill the two vertical mounting holes through the oil cooler ledge. f) Position the upper and lower B229-2 lips at the inlet of the scroll. Adjust the clearance to the edge of the cooling fan to 0.030-0.070 inch. Clamp into position and match drill the lips to the scroll. g) Remove the scroll and fan. Drill the remaining marked mounting holes, with a #18 drill bit. Assemble the A 185 brackets on the drill fixture. Position the brackets on their alignment marks on the scroll. Drill through the brackets and scroll with a #40 drill bit. Position the reinforcing plates on the inside of the scroll. Enlarge the holes in the brackets, scroll and reinforcing plates with a #30 drill bit. Disassemble and de burr the holes. Reassemble and rivet the brackets and reinforcing plates using MS20470AD4 rivets. Change 11: 7 AUG 92 Page 6.16A ROBINSON MAINTENANCE MANUAL MODELA22 6.250 Cooling Scroll Replacement (cont'd) h) Position one NAS679A08 nutplate on upper scroll half at vertical mounting hole on inboard right hand side. Drill and rivet nutplate in position with flush head rivets. i) Trim top and side edges of scroll upper half parallel with sheet metal cool panel flanges as required to maintain an edge distance of 0.01-0.02 inch j) Trim upper scroll at lower actuator mounting bolt as necessary. No contact with bolthead is permitted. k) Epoxy prime and paint grey. I} Install fan wheel per Section 6. 220. s / FIGURE 6-5A LOWER ACTUATOR BEARING INSTALLATION (VIEW LOOKING AFT) I I I I J A236-1 1 UPPER SCROLL I HALF I I A236-4 LOWER SCROLL HALF Page 6.16B Change 23: JAN 2005 ROBINSON MAINTENANCE MANUAL MOOELR22 TRIM EXCESS - FLUSH MARK AND DRILL MATCH DRILL MARK AND DRILL TO .18 IN. (SAME ON USING #18 BIT TO SHEET METAL USING #18 BIT BOTH SID~ES). --- J SHROUD US~ING MATCH DRILL #18 BIT. TO SHEET METAL ~ =----==-~---=:,,,,,- ·.-=-==----!a.~- SHROUD USING ~ ~ ~ •:~ T__:_::rs -t =111 # 18 BIT. ~ I /\ t_ II~~ + MATCH DRILL 7TO SHEET METAL SHROUD USING #18 BIT. Change 11: 7 AUG 92 .,__ ' l - - - - - - -,, ,,. - ...J \ \ ,, / \ I ✓ ,. I FIGURE 6-5B COOLING SCROLL REPLACEMENT MARK AND DRILL USING #18 BIT Page 6.16C ROBINSON MAINTENANCE MANUAL A236-l UPPER SCROLL MOLDING .030- .070 IN.~ TOP AND BOTTOM r: :B229-2 """--=~l,, ✓✓ 1 I LIP~ ... r :i I f MATCH DRILL THRU -- -- -- - 1 FIBERGLASS 8 PLCS. USING #18 BIT A236-3 I+ Ill I Ill I 11 1 I 11: I 11 1 I II, + LOWER SCROLL __ _ MOLDING ', I ',,I I : ,---------- I ·- -..J FIGURE 6-SC COOLING SCROLL REPLACEMENT (FAN LIP POSITIONING) MOCELR22 Page 6 .16D Change 11: 7 AUG 92 ROBINSON MAINTENANCE MANUAL BOLT 90° ELBOW FITTING OILLINE_/ (Oil from engine) FORWARD OIL COOLER 90° ELBOW FITTING FIGURE 6-6 OIL COOLER INSTALLATION Change 26: APR 2007 MOCEL R22 ~BOLT 6.17 ROBINSON MAINTENANCE MANUAL MOCEL R22 6.300 LUBRICATION SYSTEM NOTE Refer to Pilot's Operating Handbook for grade and quantity of oil required. Refer to the Textron-Lycoming Operator's Manual for adjustment and maintenance of the lubrication system. 6.310 Oil Cooler Removal 1. Disconnect oil lines at cooler. 2. Remove four screws and nuts connecting support to panels. 3. Disconnect four mounting bolts and remove oil cooler and attached support. If replacing cooler do NOT attempt to remove and transfer blue-anodized 90 degree elbow fittings (steel fittings may be removed). 6.320 Oil Cooler Installation NOTE Seal elbows' pipe threads with B270-6 sealant prior to installing in oil cooler. Torque elbows per Section 1 .320. CAUTION Hold threaded fittings on oil cooler with wrench to react torque when tightening elbows. 1. Install oil cooler and attached support to engine cooling panels using four mounting bolts. Torque AN3 bolts per Section 1.320 and torque stripe per Figure 2-1. 2. Install four screws and nuts connecting support to cooling panels (See Figure 6-6). 3. Connect oil lines, torque nuts per Section 1 .330, and and torque stripe per Figure 2-1. 6.400 INDUCTION SYSTEM 6.410 Carburetor Removal 6.18 1. Disconnect air intake and carburetor heat hoses from air box. 2. Disconnect throttle linkage from carburetor bellcrank, mixture control cable from carburetor and carburetor heat control cable from air box slider valve. 3. Disconnect carburetor air temperature probe wiring. 4. Remove palnuts and nuts securing carburetor to intake manifold and remove carburetor and attached air box assembly. Change 26: APR 2007 ROBINSON MAINTENANCE MANUAL MOCEL R22 6.420 Air Box Removal 1. Disconnect air intake hoses from air box. 2. Disconnect mixture control cable clamp(s) from air box. 3. Disconnect mixture safety spring from carburetor mixture control arm. 4. Open air box cover and remove air filter. 5. Disconnect carburetor heat control cable from air box and slider valve. 6. Cut safety wire and remove four bolts (or cap screws) securing air box to carburetor and remove air box and rubber gasket. 6.430 Air Box Installation 1. With air inlets on right, install air box and rubber gasket on carburetor and secure with bolts and washers (or cap screws and spacers on R22 S/Ns 25 71-2664 with C05 7 air box). Torque fasteners per Section 1. 330 and safety with 0.032 inch diameter safety wire. 2. Connect mixture control safety spring to carburetor mixture control arm. Verify spring moves arm to full rich position. 3. See Figure 6-7. Connect mixture control cable housing to air box. Push and pull on cable housing and verify it does not slip in clamp(s). 4. See Figure 6- 7. Connect mixture control cable inner wire to mixture control arm. Verify mixture control moves carburetor mixture control arm stop to stop. Verify 0.03/0.10 inch clearance (spring-back) under knob at full-rich position. If required, adjust position of inner wire in A462 fitting. Torque A462 fitting per Section 1 .330. Install palnut, torque per Section 1 .320, and torque stripe. 5. Connect carburetor heat control cable to air box. Connect carburetor heat control cable inner wire to slider valve and torque A462 fitting per Section 1.330. Verify carburetor heat control fully opens and closes slider valve. Bend free end of inner wire ninety degrees where it exits A462 fitting, then cut wire as required to leave 0.25/0.50 inch remaining. Install palnut, torque per Section 1.320, and torque stripe. 6. Install air filter, close cover, and secure. Tighten four long bolts only enough to secure cover and eliminate looseness, then torque stripe. On R22 Mariners, seal air box cover perimeter with aluminum tape. If installed, verify spring-loaded alternate air door fully closes when released. 7. Connect air intake hoses to air box. Change 26: APR 2007 6.19 ROBINSON MAINTENANCE MANUAL MODEL R22 AIRBOX CABLE MOUNT r. MIXTURE CONTROL CABLE .'\ MIXTURE CONTROL ARM FUEL INLET AND FU EL SCREEN ~Q '~"-- ACCESS ~ MIXTURE CONTROL / ~ I SAFETY SPRING / -~- AND BRACKET ~ . ------ MIXTURE CONTROL/ ~~=:::::::::::;r- _,,....- - • WIRE END TO ARM-STOP / . REMAIN STRAIGHT ENSURE FREEDOM OF -- ROT A TION BETWEEN MIXTURE CONTROL CABLE ~ ~ARM A~D INNER WIRE - -==-=----e:: ~ ---- ' ' 0'.: MIXTURE CONTROL ~ CARBURETOR CABLE CLAMPIS~ 1/~----:::_ ::::_ ~ AIRBOX • AIRBOX CABLE MOUNT BRACKET - FIGURE 6-7 MIXTURE SAFETY SPRING INSTALLATION 6.20 Change 26: APR 2007 6.435 Air Filter Cleaning NOTE Replace B771-1 air filters after 5 years or 600 flight hours, whichever occurs first. 1. Remove B771-1 air filter from airbox. Visually inspect filter and verify no obvious damage. Inspect filter’s pleated media for cleanliness. If the media contains only dust, clean media using compressed air or water. Clean heavily soiled media using a mild soap & water solution. a. Compressed air: Maintain at least one-inch distance between air nozzle and pleated media and apply less than 40 psi compressed air thru media opposite the normal direction of airflow. b. Water: Apply less than 40 psi water stream thru media opposite the normal direction of airflow. Dry filter thoroughly using less than 160°F warm air. c. Mild soap & water solution: Apply less than 40 psi water stream thru media opposite the normal direction of airflow. Soak filter in a mild soap and water solution for more than 15 minutes but less than 4 hours. Gently agitate filter in soap solution to help remove dirt. Apply less than 40 psi water stream thru media in both directions. Dry filter thoroughly using less than 160°F warm air. 2. Using a bright light, examine pleated media and verify no holes or tears. 3. Verify filter sealing surfaces are a smooth, continuous circle and flat. NOTE Do not install a wet air filter. Do not apply oil to filter media. 4. Install filter in airbox. NOV 2020 Chapter 6 Powerplant Page 6.21 ROBINSON MAINTENANCE MANUAL R22 SERIES 6.440 Carburetor Installation 1. With carburetor butterfly bellcrank on left, install carburetor and new gasket on mounting studs of engine sump and secure with washers and nuts. Special torque nuts per § 23-33. Install palnuts, standard torque per § 23-32, and torque stripe. 2. Connect throttle push-pull tube to middle hole of carburetor butterfly bellcrank. Standard torque bolt per § 23-32. Install palnut, torque per § 23-32, and torque stripe. 3. See Figure 6-7. Connect mixture control cable inner wire to carburetor mixture control arm. Lightly tighten A462 fitting, but do not torque; fitting will be torqued in following step. 4. Install air box per § 6.430. 5. Verify idle RPM and idle mixture per § 2.210. 6. Check throttle correlation rigging per § 10.150. 6.450 Carburetor Heat Scoop Removal 1. Disconnect hose from carburetor heat scoop. 2. 0-320 engine: Remove six screws securing curved sheet metal and remove sheet. 0-360 engine: Remove two B277 clamps securing scoop assembly to exhaust manifold and remove scoop. 3. 0-320 engine: Remove four bolts securing scoop assembly to bead clamp on exhaust riser and remove scoop assembly. Remove additional clamp from exhaust riser above bead clamp. 6.460 Carburetor Heat Scoop Installation 1. 0-320 engine: Install A694 clamp and angle on #4 cylinder exhaust riser and lightly tighten. Attach scoop assembly on bead clamp and lightly tighten. 0-360 engine: Install scoop assembly, secure with B277 clamps, and lightly tighten. 2. Connect air inlet hose to scoop assembly. 3. 0-320 engine: Position sheet on mounts. Move A694 clamp and rotate bead clamp (with attached scoop assembly) as required to minimize preload and ensure clearance from surrounding structure. Tighten A694 clamp. Standard torque bolts per § 23-32. Install sheet with six screws. 0-360 engine: Move scoop assembly as required to minimize preload and ensure clearance with surrounding structure. Special torque scoop attach clamps to 30 in.-lb. Page 6.22 Chapter 6 Powerplant NOV 2020 ROBINSON MAINTENANCE MANUAL R22 SERIES 6.500 Exhaust System 6.510 Exhaust System Removal 1. Remove carburetor heat hose and, if installed, disconnect heater hoses from muffler shroud. 2. Protect landing gear aft cross tube with suitable covering. Disconnect exhaust flanges at cylinder heads and remove exhaust system and gaskets. 6.520 Exhaust System Installation NOTE Do not use stainless tape beneath exhaust bead clamps which incorporate integral barriers. 1. Position a gasket on each exhaust port. 2. Protect landing gear aft cross tube with suitable covering. Position exhaust system on engine and connect riser exhaust flanges to cylinder heads with washers and nuts. Remove protective cover from cross tube. 3. Loosen bead clamp on each riser. If required, remove curved metal sheet from carb heat scoop assembly. 4. Special torque exhaust flange nuts per § 23-33. Install palnuts and standard torque per § 23-32. 5. Install carburetor heat hose and connect heater hoses, if installed. 6. Standard torque bead clamp AN3 bolts per § 23-32. If removed, install curved metal sheet on carburetor heat scoop assembly and reposition clamps as required to minimize preload and ensure clearance from surrounding structure. NOV 2020 Chapter 6 Powerplant Page 6.22A ROBINSON MAINTENANCE MANUAL R22 SERIES Intentionally Blank Page 6.22B Chapter 6 Powerplant NOV 2020 ROBINSON MAINTENANCE MANUAL R22 SERIES ROBINSON MAINTENANCE MANUAL MODELR22 6.610 LOW-POWER CHECKLIST When low engine power output is suspected, use the following checklist to verify: 1. Aircraft gross weight is not exceeded. Weigh aircraft if it was not weighed at last overhaul. 2. Engine oil pressure, oil temperature, and CHT are within limits. 3. MAP gage indicates ambient pressure (engine off). 4. Proper grade of fuel per Pilot's Operating Handbook. 5. Main rotor blades are clean and smooth (no rough paint). 6. Exhaust is unobstructed. 7. Main rotor blade trim tabs are not excessively bent. 8. Carburetor heat valve closes fully in OFF position. 9. Induction system is unobstructed. Air filter and both inlet hoses (ambient and carburetor heat) are clean, undamaged, unobstructed, and do not collapse in flight. Carburetor-to-engine gasket is correct size. 10. Engine tachometer indication is correct. Verify with digital tachometer (such as found in newer dynamic balancing equipment) or similar equipment. 11 . Oil screens or filter do not exhibit metallic debris consistent with internal engine damage. 12. Proper cylinder compression (both leakage and direct) per Lycoming recommendations. 13. Mixture neither excessively lean nor rich. Compare fuel flow. Verify fuel filter cleanliness, check spark plug indications, check carburetor throttle body-to-float bowl screw security per Lycoming SB 366. 14. Proper spark plug type and condition. 15. Proper magneto-to-engine timing. Verify engine-left (helicopter-right) magneto is not operating in retard mode when ignition switch is in BOTH position (disconnect retard terminal after starting engine and compare hover MAP indications; lesser hover MAP with retard terminal disconnected indicates magneto was operating retarded). 16. Proper fuel flow and unobstructed carburetor fuel inlet screen. Perform fuel-flow check per Section 1 2. 17. If primer-equipped, verify fuel is not leaking past primer pump (ensure primer pump is locked) and air is not leaking past fittings in cylinder head. Change 22: MAR 2004 Page 6.23 ROBINSON MAINTENANCE MANUAL MOCELR22 I 6.610 LOW-POWER CHECKLIST (cont'd) 18. Carburetor or fuel control throttle lever contacts full-throttle stop (collective must be raised slightly). 19. Carburetor or fuel control mixture arm contacts stop when mixture control is in full-rich position and mixture arm does not exhibit springback at extremes of travel when disconnected from control cable/safety spring (due to internal binding). 20. No induction/MAP system leaks. To check MAP system, disconnect MAP line at cylinder head fitting and apply suction with syringe until MAP gage indicates 10 inches Hg. Monitor gage for one minute; indication should rise no more than 1 inch Hg. Verify carburetor throttle shaft bushings are not worn; check both axial and radial clearances. Intake leaks can also occur due to loose intake pipe connections in oil sump and/or cracked sump runner tubes. For 0-320-B2C engines only, incorrect thin-flanged intake pipes P/Ns 61363, 61364, or 61365 used in place of correct P/Ns LW-16728, LS-16729, and LW-16730 can cause leaks in conjunction with deep-counterbore flange P/N 74360. 21 . Proper exhaust valve guide clearance per Lycoming SB388B. 22. Proper dry-tappet clearance per Lycoming Overhaul Manual. 23. With lifters pumped up (valve lash removed), each intake valve should exhibit equal travel during opening when measured with a dial indicator. Similarly, each exhaust valve should exhibit equal travel during opening. Unequal travel indicates damaged cam lobe(s). 24. Proper magneto internal timing. 25. Carburetor float bowl fuel level correct. 26. Cylinder head intake port has radiused edge where inlet airflow turns 90 degress toward valve. If no radius exists, contact Lycoming Technical Support. 27. Proper crankshaft-to-camshaft timing: As #1 piston passes TDC on compression stroke, the #2 intake valve should open while the #2 exhaust valve closes (valve overlap position). 28. If 0-320/0-360/0-540 engine exhibits low-power immediately after overhaul, verify correct 8.5: 1 compression ratio piston P/N 75089 has been installed (instead of 7.0:1 low compression piston P/N 75413). Page 6.24 Change 22: MAR 2004 6.620 High Cylinder Head Temperature (CHT) Indication 1. For any helicopter indicating unusually high CHTs, verify: a. Proper fuel grade. b. Cooling scroll inlet metal lips-to-fanwheel clearance is within 0.020–0.100 inch. c. Mixture control at carburetor is at full-rich position when mixture knob is fully in. d. Integrity of engine baffles and cooling panels. e. Cooling hoses are properly routed, secured, and in good condition. f. Correct spark plugs (Lycoming Service Instruction 1042 refers). g. Magnetos are properly timed. h. No excessive leakage from exhaust riser-to-cylinder head gaskets. NOTE Cylinder head temperatures may be higher during engine break-in until oil change and switch from mineral to ashless dispersant oil. 2. If preceding steps and corrective actions do not improve CHT indications, the CHT gage may be indicating erroneously high. Refer to § 33-131-2 Part E. NOV 2020 Chapter 6 Powerplant Page 6.24A ROBINSON MAINTENANCE MANUAL R22 SERIES Intentionally Blank Page 6.24B Chapter 6 Powerplant NOV 2020 ROBINSON MAINTENANCE MANUAL R22 SERIES ROBINSON MAINTENANCE MANUAL MOCEL R22 6.700 THROTTLE CONTROL AND CARBURETOR HEAT ASSIST The throttle control consists of a twist grip integral with the collective control, an overtravel spring, throttle bellcrank, throttle push-pull tube, a carburetor throttle lever, and carburetor heat assist factory installed on S/N 25 71 and subsequent. 6. 719 Overtravel Spring (Refer to Figures 8-6 and 10-8) 6. 711 Overtravel Sr:iring Removal 1. Remove belly panel and vertical panel between seat backs. 2. Disconnect A327-1 overtravel spring's upper rod end from collective throttle arm. 3. Disconnect A327-1 overtravel spring's lower rod end from bellcrank. 4. Remove overtravel spring. 6. 712 Overtravel Spring Installation 1. Connect overtravel spring's lower rod end to bellcrank and torque per Section 1 .32. Install palnut, torque per Section 1.320, and torque stripe per Figure 2-1. 2. Connect overtravel spring's upper rod end to collective throttle arm. Raise collective fully, and with throttle twist grip rotated full closed, verify dimension shown in Figure 10-8; adjust upper rod position as required. Torque screw per Section 1 .330. Install palnut, torque per Section 1 .320, and torque stripe per Figure 2-1. 3. Install belly panel and vertical panel between seatbacks. 6. 720 (Reserved) Change 26: APR 2007 6.25 ROBINSON MAINTENANCE MANUAL MO □ EL R22 6. 730 Throttle Push-Pull Tube Assembly ~?_3_1 Throttle Push-Pull Tube Assembly Removal 1. Remove cover enclosing bellcrank beneath left seat baggage compartment. Disconnect throttle push-pull tube assembly from bellcrank. 2. Disconnect throttle push-pull tube assembly from carburetor and remove. 6. 732 Throttle Push-Pull Tube Assembly Installation (Refer to Figure 10-8) 1. Insert throttle push-pull tube assembly forward thru firewall seal. Attach aft end to middle hole of carburetor throttle lever and tighten bolt. 2. Attach throttle push-pull tube assembly to bellcrank and tighten bolt. 3. Adjust throttle correlation rigging per section 10.150. Torque push-pull tube jam nuts(s) and palnut(s) (if installed), per Section 1 . 320 and torque stripe per Figure 2-1. 6. 740 Carburetor Heat Assist 6.26 A carburetor heat assist device is installed on R22s with 0-360 engines. The carb heat assist correlates application of carburetor heat with changes in collective setting to reduce pilot work load. Lowering the collective mechanically adds heat and raising the collective reduces heat. Collective input is transmitted through a friction clutch which allows the pilot to override the system and increase or decrease heat as required. A latch is provided at the control knob to lock carburetor heat off when not required. 6. 741 Carburetor Heat Control Removal 1. Open air box. 2. Remove horizontal cover between seats. 3. Drive out spring pin on cyclic friction knob using a pin punch. Remove cyclic friction knob. Unscrew knob and collar from carb heat assist stem. 4. Raise cyclic cover and secure out of the way. 5. Remove and discard palnuts from carburetor heat slider valve fittings. Discard palnuts. 6. Loosen nut(s) securing carburetor heat control inner wire to valve. 7. Remove cotter pin and washer securing forward end of control to D334 bellcrank assembly. 8. Pull center wire out of conduit. 9. Remove 8270-5 sealant surrounding conduit at vertical firewall. Remove screws securing conduit to keel panel and airbox. 10. Remove outer conduit. Change 26: APR 2007 ROBINSON MAINTENANCE MANUAL MO □ EL R22 E3_._71O_~_cl_rQ!J_r-etor Heat A_ssL~t (Cont'd) 6. 742 Carburetor Heat Control Cable Installation 1. Pull inner wire from new control. Route and secure conduit along keel panel, thru vertical firewall, and into air box with retained hardware. 2. Replace B270-5 sealant around cable at firewall pass-through. 3. Lubricate inner wire with A257-1 grease, insert into conduit. Connect forward end to bellcrank, install washer, and temporarily install cotter pin. 4. Secure cyclic cover in place, install collar and knob on stem. Verify 0.10 to 0.25 inch clearance between fitting on inner wire and forward end of conduit with control knob fully down. Reposition conduit as required. 5 Verify aft end of conduit has 0.00 to 0.1 5 inch protrusion into air box. As required, remove inner wire and trim conduit. Install inner wire, connect forward end to 0334 bellcrank, install washer and secure with cotter pin. 6. Connect inner wire thru fitting(s) in carb heat slider valve. With knob fully down and slider valve fully aft, trim inner wire 0.10 to 0.03 inch beyond aft edge of fitting. Torque nuts on fittings per Section 1 .330. Torque stripe per Figure 2-1 . 7. Install air filter, close cover, and secure. Tighten four long bolts only enough to secure cover and eliminate looseness, then torque stripe. On R22 Mariners, seal air box cover perimeter with aluminum tape. If installed, verify spring- loaded alternate air door fully closes when released. 6. 743 0334-5 Carburetor Heat Assist_Bellcrank Assembly Removal 1. Remove belly panel and horizontal panel between seats. 2. Disconnect carburetor heat assist control inner wire from bellcrank. 3. Disconnect carb heat assist push-pull tube from B249 arm assembly. Remove six screws securing bellcrank assembly to keel panel and B368 stiffener. 4. Remove bellcrank assembly. 6. 744 0334-5 Carburetor Heat Assist Bellcrank Assembly Installation 1. Position bellcrank assembly against, and with bearing block protruding thru, right keel panel. 2. Secure plate to keel panel with screws. 3. Install A 142 screws thru stiffener into bearing block. Torque to 45 in.-lb and torque stripe. 4. Attach A336 push-pull tube to B249 arm assembly and torque bolt per Section 1 .320. Install palnut, torque per Section 1.320 and torque stripe per Figure 2-1. 5. Lubricate 0333-3 fitting at forward end of carb heat control with A257-1 grease and secure to bellcrank with washer and cotter pin. Change 26: APR 2007 6.27 ROBINSON MAINTENANCE MANUAL MO □ EL R22 NAS6603- 7 BOLT AN960PD 1 OL WASHER (under head) A 142-4 SCREW NAS1149F0332P WASHER (torque to 45 in.-lb; includes locking torque) A141-16 WASHER (0.688 in. outside diameter; 3 required) 2 places A141-16 REF B250-8 JOURNAL (0.100 in. long) / NAS6606-16 BOLT NAS1149F0632P WASHER MS21042L6 NUT (torque to 280 in.-lb; includes nut self-locking torque) B330-19 PALNUT A647-12 BEARING (2 required) B250-5, -6, -7, -10, or -12 JOURNAL (2 required*) 6.28 D333-10 BLOCK D333-11 PLATE ~ B250 Journal Lengths (thickness): B250-5 : 0.059 inch long B250-6 : 0.062 inch long B250-7 : 0.065 inch long B250-10: 0.068 inch long B250-12 ; 0.071 inch long ~ D333-1 BELLCRANK B1000-035-S SPRING WASHER (2 required, orient as shown} A141-35 WASHER (2 required) NAS1149F0663P WASHER *Install B250-5, -6, -7, -10, or -12 journals as required to produce a rotational friction of 10-12 inch-pounds. Journal dash numbers may be mixed. Measure rotational friction by clamping long side of D333-11 plate in padded vise w/B249-7 arm assembly against vice jaws and rotating bolt head with dial- indicating torque wrench. FIGURE 6-8 D334 BELLCRANK ASSEMBLY CARB HEAT ASSIST FRICTION ADJUSTMENT (View looking aft) Change 26: APR 2007 ROBINSON MAINTENANCE MANUAL MODEL R22 6. 745 D334-5 Bellcrank Friction Adjustment (Refer to Figure 6-8) NOTE Verify bolt head between arm and plate. 1. Measure rotational friction per Figure 6-8. 2. Adjust friction as required by exchanging B250 journals per Figure 6-8 (dash numbers may be mixed). Decreasing journal thickness increases friction. Torque NAS6606 bolt per Figure 6-8. 3. Install palnut, torque per Section 1.320, and torque stripe per Figure 2-1. Change 26: APR 2007 6.29 ROBINSON MAINTENANCE MANUAL MODEL R22 Intentionally blank 6.30 Change 26: APR 2007