AMM 1.0.0.0PROPELLER ASSEMBLY (FIVE-BLADED PROPELLERS) - MAINTENANCE PRACTICES NOTE: For six-bladed propeller assemblies (aircraft equipped with PT6A-67R engines), refer as follows: 1. Servicing Model HC-A6A-3 (pre Hartell SB 168). Refer to 61-10-02, pb201. Model HC-A6A-3A (post Hartell SB168). Refer to 61-10-03, pb201. A. Lubricate blade clamps. Refer to 12-22-61, pb301. 2. Removal/Installation Special Tools & Equipment:- Table, Propeller Setting: Protractor, Blade Setting: Wrench, Blade Clamp bolts: Puller, Beta Ring: Sling, Propeller: Wrench, Propeller Mounting bolts: Blade bar, Blade Slippage check: Dial Indicator Gauge, (Run-out checks): Rig, Unfeathering: T360-61-02 T360-61-03 T360-61-04 T360-61-05 T360-61-07 T360-61-08 T360-61-09 Operators Supply Operators Supply A. Remove a propeller assembly (1) Remove spinner dome (2) Remove cowl 430AT and hinge down cowl 420BB. (3) Refer to Figure 201. Remove propeller reversing lever to disengage associated slipper block from the propeller low stop collar:- (a) Disconnect lever (2) from clevis (3) at front end of push-pull control terminal (4) by removing cotter pin, castellated nut and bolt (5). (b) Disconnect lever from Beta valve plunger (6) on propeller governor (7) by removing cotter pin, washer and pin (8). Page 201
SD3-60 AIRCRAFT MAINTENANCE MANUAL (c) Remove lever and remove spacer (9) and bushing (10) to prevent loss of these parts. NOTE: Do not remove carbon slipper block (11) from lever. (4) Detach the fine pitch back-up and reverse pitch indication mechanism where attached to the thrust bearing cover on the reduction gearbox. Extricate the associated slipper block from the low stop collar on the propeller and temporarily stow the assembly clear of the propeller mounting flange. (5) Fit beta ring puller to the low stop rods support ring around propeller piston and wind the ring forward such that the low stop collar is positioned to provide optimum access to propeller mounting bolts. (6) Sling the propeller. (7) Break the lockwire and remove the eight attachment bolts and washers which secure the propeller assembly to the engines propeller shaft. Pull the propeller forward to disengage from the dowel pins on the propeller shaft flange and lower unit clear. (8) Remove the O-ring from the propeller shaft. B. Install a propeller assembly (1) If propeller assembly to be installed is in 'shipped' condition, carry out preparation procedure detailed in para C. (2) Clean the respective mounting faces of the propeller assembly and the engines propeller shaft. Remove any sharp edges which might prevent mating. (3) Ensure that the four dowel pins are fitted to the mounting flange on the engine propeller drive shaft. (4) Fit O-ring, Pt. No. PRP-909-8 to drive shaft. NOTE: Use PRP Compound 1487 or 8307 to fit O-ring. (5) Fit beta ring puller to the low stop rods support ring around propeller piston and wind the ring forward such that the lower stop collar is positioned to provide optimum access to the propellers mounting flange for installation. (6) Sling the propeller and raise to installation position. Page 202
Reversing Lever - Removal/Installation Figure 201 Page 203
SD3-60 AIRCRAFT MAINTENANCE MANUAL (7) Attach propeller to drive shaft on engine, engaging dowel pins. Ensure that complete and true surface contact is established and fit attachments as follows:- (a) Apply MIL-T-5544 Petrolated Graphite to threads of the eight bolts, Pt. No. B-3339 and to the bolt-to-washer interface of the eight washers, Pt. No. A-2048-2. NOTE: Graphite grease may also be applied to shanks of bolts, if desired. (b) Refer to Figure 202. Fit the bolts and washers, torque tightening to 40 ft lb and then to 80 ft lb following torque sequence 'A'. (c) Final torque all bolts using sequence 'B' to 100 to 105 ft lb. (d) Wirelock bolts together in pairs (figure-of-eight). (8) Remove sling. (9) Remove beta ring puller. (10) Carry out blade slippage check (refer to para 3.). NOTE: Operation (11) is to be ignored on aircraft which have propeller de-icing inhibited. (11) Check propeller de-icing brush block alignment and carry out de-icing function test as detailed in Chapter 30. (12) Re-attach the fine pitch back-up and reverse pitch indication mechanism to the thrust bearing cover on the reduction gearbox, inserting the associated slipper block within the low stop collar on the propeller. (13) Refer to Figure 201. Refit the propeller reversing lever as follows:- (a) Press bushing (10) into centre hole of lever (2). (b) Position slipper block (11) in propeller low stop collar. Insert centre boss of lever (2) into clevis on Beta valve plunger (6) of propeller governor (7). Secure lever in clevis with pin (8), washer and cotterpin. (c) Press spacer (9) into upper hole in propeller reversing lever (2). Secure lever in clevis (3) with bolt (5) and castellated nut. Torque tighten nut to between 24 and 36 lb. in. and install cotterpin. (14) Rotate propeller and check that the side clearance of both slipper blocks in the low stop collar is 0.001 to 0.002 in. NOTE: Discard any block with clearance in excess of that quoted and appropriately lap evenly the sides of any tight block to come within tolerance. (15) Refit spinner dome and cowlings. Page 204
Torquing Sequences - Propeller Attachment Bolts Figure 202 Page 205
SD3-60 AIRCRAFT MAINTENANCE MANUAL (16) Rotate propeller and check that clearance exists between the spinner and engine cowlings. (17) Remove the POWER, FUEL and PROP lever cover assembly from the top of the centre console in the flight compartment. (18) Refer to 71-00-00, pb1. Start and run engine and perform the following checks (adjusting as necessary):- (a) Check flight fine pitch angle (b) Set reverse maximum power NOTE: This will set the operational max. reverse blade angle (the angle set during propeller assembly merely provides overtravel). (19) Shutdown engine and refit console cover. C. Prepare propeller for installation. General information This procedure relates to the preparation of a propeller assembly from received (shipped) condition. The propeller has been assembled and balanced by the manufacturer. The blade angles relative to the clamps have been marked with matching red tape attached to the clamp and blade shank. Grease has been installed in the blade-hub system. Matching corresponding numbers (1 to 5) have been put on each blade and its associated clamp. For convenience of shipping, up to four blades may have been removed from the assembly. The clamps were re-installed on the hub. The blade ends were wrapped to preserve the grease and to keep out foreign matter. The spinner and unfitted blades are respectively packaged separately from the main propeller assembly. Procedure Refer to Figure 203. (1) Mount the propeller-hub on the setting table spindle as follows:- (a) Fit O-ring, Pt. No. PRP-909-8 to the spindle. (b) Mount propeller on spindle, engaging dowels. (c) Fit the eight propeller mounting bolts and washers. Torque tighten to installation value i.e. 100 to 105 ft.lb (greased threads). Page 206
Propeller Assembly Figure 203 Page 207
SD3-60 AIRCRAFT MAINTENANCE MANUAL (2) Check slip ring run-out as follows:- (a) Suitably secure a dial indicator gauge to the setting table, bring pointer into contact with a slip ring and adjust dial to ero. (b) Rotate propeller slowly and note the deviation from a true plane is indicated by the gauge. NOTE: The run-out should not exceed (i) 0.008 in. in total and (ii) 0.002 in. within any four inches of slipring travel. CAUTION: REFER TO FIGURE 204. THE BELLEVILLE WASHER MUST BE INSTALLED AS SHOWN. IF THE WASHER IS NOT INSTALLED AS SHOWN, YOU WILL DAMAGE THE SLIPRING AND THE SPINNER BULKHEAD. (c) If tolerances quoted in preceding note are not met, then: excess run-out may be corrected by circumferentially varying the torque of the slipring/spinner bulkhead attachment bolts within their specified limits of 40-100 lb.in. (Belleville washers are introduced between the mating faces of the spinner bulkhead and slipring. Refer to Figure 204. (3) Check that the distance between the rear faces of the low stop collar and propeller flange is 1.80 + 0.005-0.020in. as shown (4) Install unfitted blades in turn as follows:- (a) Remove temporary fitted blade clamp assembly from propeller hub; this entails:- 1 Disconnecting the link arm on the clamp from its attachment to the propeller piston (remove safety screw and withdraw link pin unit). 2 Removing the two socket head screws and two clamp bolts and nuts from the clamp assembly. Remove the clamp, complete with link arm from the hub. (b) Without disturbing the grease in the blade shank, fit the relevant blade to the hub pilot tube. (c) Apply an automotive type gasket compound around the shoulder area of the blade to seal the clamp against grease leaks. (d) Without disturbing the grease which is packed around the blade bearings, fit blade clamp assembly with a clamp gasket (Pt. No. A-1306-1) placed between each of the two clamp jointing lines. NOTE: The clamp parting surfaces should be free of grease. (e) Fit the two socket head screws (Pt.No.A-282) to clamps. Do not tighten at this stage. Page 208
Slipring Attachment Figure 204 Page 209
SD3-60 AIRCRAFT MAINTENANCE MANUAL (f) Fit the two clamp bolts, Pt.No.A-1372 (alternatively A-1379) and clamp nuts (Pt.No.A-1373). Do not tighten at this stage. (g) Tighten socket head screws just sufficiently to support blade. (h) Re-align link arm on clamp assembly with its pick-up lugs on the propeller piston. Fit the link pin unit, securing with safety screw. Wirelock. (5) Set the pitch of each blade by aligning the red tape on the blade root with the red tape on the corresponding blade clamp. (6) Tighten the socket head screws and clamp bolts to respective torque values of 40 lb.ft. and 60-65 lb. ft. NOTE: Ensure that the red tape remain matched precisely during this operation. (7) Lock the two socket head screws on each clamp assembly by the following means:- (a) At blade leading edge - fit split pin (b) At blade trailing edge - wirelock. NOTE: The nuts on the clamp bolts are not to be locked at this stage. (8) Connect unfeathering rig to propeller table. (9) Temporarily position elastic nuts, Pt.No.A-2043 towards forward ends of low stop rods. NOTE: These nuts will subsequently be wound back to establish the low hydraulic stop position. (10) Refer to Figure 205. Place protractor on front face of piston as shown and adjust to ero. NOTE: Curved side of the protractor must face towards setting table. (11) Pencil identify for subsequent installation and remove the weight slugs, Pt.No. from the counterweight on each blade clamp. NOTE: This is necessary to (a) permit counterweight angle check-position (13) and (b) allow for subsequent installation of de-icing harness. (12) Operate rig, raise and maintain pressure at 200 psi. to force propeller piston to the full reverse position. (13) Place protractor on the side of each counterweight in turn and check that adjustment to re-centre protractor bubble will provide an indication of between + 1.5 and + 3.5 from the propeller axis towards feather. Refer to Figure 206. Page 210
Protractor - Initial Setting Figure 205 Page 211
SD3-60 AIRCRAFT MAINTENANCE MANUAL (14) With the propeller piston maintained at full reverse, choose a blade (remember ident number) and set protractor on the 42 in. radius station. Check that when protractor is adjusted to centre bubble a reverse blade angle of-11 0' ± 30' is indicated. If blade angle is outside quoted limits, then:- (a) Slacken outer clamp bolts on the blade clamp (b) Set protractor to required blade angle. (c) Again locate protractor on blade checking station. (d) Using a blade bar carefully turn blade within clamp until protractor bubble centres. (e) Torque tighten outer clamp bolts to 60-65 lb.ft. Lock clamp nuts with split pins. (15) Set protractor to 16 30' ± 12' and place on the checking station of the blade set at operation (14). (16) Bleed pressure out of the piston until the protractor bubble centres (blade at low pitch) Maintain this angle. (17) Check that remaining four blades are positioned at 16 30' ±12' : if not, carry out procedures (a) to (e) inclusive of operation (14). (18) With the blades held at low pitch, position the elastic nuts, Pt.No.A-2043 (on the three low stop rods) to lightly grip a 0.002 in. feeler between the nut and the boss on the propeller piston through which the low stop rods slide. This establishes the low hydraulic stop position. (19) Operate the rig and move the piston slightly towards reverse such that the low stop collar (Pt.No.C-4019) enters its operational range. (20) Check the collar run-out as follows:- (a) Suitably secure a dial indicator gauge to the setting table; bring pointer into contact with the rear face of the collar and adjust dial to ero. (b) Rotate propeller slowly and note the deviation from a true plane as indicated by the gauge. The total run-out should not exceed 0.010 in. NOTE: If run-out exceeds 0.010 in. then:- 1 Note direction that low stop rod/s must be turned to correct run-out. 2 Release oil pressure from piston. 3 Slacken jam nut A-3459 and elastic nut 52NTE-064 on stop rods requiring adjustment. DO NOT DISTURB LOW STOP ELASTIC NUTS A-2043. Page 212
Counterweight Angle Check Figure 206 Page 213
SD3-60 AIRCRAFT MAINTENANCE MANUAL 4 Slightly rotate low stop rod/s in required direction. Tighten jam nut and elastic nut. 5 Repeat operation (19) and again check run-out. (21) Release pressure from piston and check feathering angle at the checking station on each blade. This should be 79 00' ± 30'. (22) Check blade track as follows:- (a) Operate rig to position blade tips at flat pitch with respect to hub axis. (b) Using a suitable reference, eg. measuring stick, rotate propeller checking that the total variation of blade track at tips for all blades does not exceed 1/8 in. (c) Release pressure from piston. (23) Refer to Figure 207. Prepare and connect propeller de-icing harness as follows:- (a) Connect the terminal lugs provided to the two wires from the de-icer on each blade. (b) Check that terminal strips are fitted to five positions on the front face of the spinner bulkhead (see detail A). (c) Attach loose terminal strips provided to the five weight slugs which were removed from the blade counterweights at operation (11) - see details A and C. NOTE: Do not re-install weight slugs at this stage. (d) Perform the following at each blade in turn:- 1 With reference to details A and B, connect one end of wiring harness 3E2017-4 and the leads from the slipring to the terminal strip on the spinner bulkhead. Match the corresponding GND and POS terminals as shown. 2 Fit cable clamp to bulkhead; attach with screw, nut and two washers (one under screw head, one under nut). 3 Identify and select weight slug appropriate to blade. 4 With reference to details A and C, connect free end of wiring harness 3E2017-4 and wiring from de-icer to the terminal strip on weight slug, again matching respective GND and POS cables. Fit cable clamp (attach with screw and washer). 5 Refit weight slugs to counterweights; tighten attachment bolts and wirelock. Page 214
De-icing Harness Installation Figure 207 Page 215
SD3-60 AIRCRAFT MAINTENANCE MANUAL Blade Bar Figure 208 Page 216
6 With reference to detail B, fit tie strap below erk fitting as shown. NOTE: Pull wiring from de-icer down tight against blade clamp when installing tie strap. (24) Remove propeller from setting table. 3. Adjustment/Test A. Check for blade slippage in clamps (1) Remove spinner dome. (2) Apply temporary alignment marks to each blade and associated clamp. NOTE: Do not employ the red tape marks. (3) Refer to Figure 208. Using a blade bar fitted to each blade in turn, apply a torque of 167 lb.ft. at right angles to the bar against the propellers feather stop. NOTE: Ideally the blade bar should be attached at a somewhat shorter radius than the blade angle checking station. (4) Check that the temporary marks are still in alignment. If not, then the appropriate clamp/ s must be removed and filed lightly on the parting line of the clamp half which does not have the raised surfaces at the four corners. This will allow the clamp to grip the blade shoulder more firmly. Refit the clamp (aligning temporary marks) and repeat procedures (3) and (4) until no slippage occurs. CAUTION: IF THE CLAMPS ARE REMOVED, THE BALLS FROM THE A-1851-T BEARINGS MAY DROP OUT. THESE SHOULD BE CAUGHT IN A CONTAINER HELD BELOW THE BEARINGS. (5) Refit spinner dome. 4. Dynamic balancing A. Equipment required Part No. (1) Balancer/Phaor unit 177M-6A 1 (2) Magnetic pick-ups 3030 2 (3) Magnetic pick-up cable 3319-2 2 (4) Magntic pick-up brackets 4912 2 (5) Accelerometers 4177B 2 (6) Accelerometer cable 4296-2 2 (7) Accelerometer bracket 3383 2 Qty. Page 217
SD3-60 AIRCRAFT MAINTENANCE MANUAL B. Test equipment installation Refer to Figure 209. Install equipment on each engine as follows:- (1) Remove access panel No.430AT and 420AB (2) Install accelerometer (3) Install magnetic pick-up and interrupter plate. Set the magnetic pick-up to achieve a clearance of 0.125 (3.17 mm) to the interrupter plate. (4) Install counterbalance washers at the screw position diametrically opposed to the interrupter plate. (5) Connect accelerometer cables to the accelerometers on each engine. (6) Connect magnetic pick-up cables to the magnetic pick-ups on each engine. (7) Route cables along the engine cowl, wing leading edge and through the forward emergency exit doors. NOTE: (a) Care should be taken to ensure that cables are routed away from the engine exhausts and are firmly secured to the aircraft structure with adhesive tape. (b) Ensure that the cables are not nipped excessively when the emergency exit doors are closed. (8) Refit access panel 430AT. (9) Connect DC power to the Balance Unit. Part No. (8) Interrupter 4282 2 (9) Balance chart - 1 NOTE: (a) The unit will operate satisfactorily from an external supply provided that the voltage is between 12 and 28 volts. (b) A convenient internal supply can be taken from distribution panel 2D using the redundant FERRY FUEL circuit breaker No.222. (10) Connect accelerometer and magnetic pick-up cables to the balance unit. (a) Connect the left and right engine accelerometer cables (three pin) to channels A and B respectively. Qty. Page 218
Test equipment installation Figure 209 Page 219
SD3-60 AIRCRAFT MAINTENANCE MANUAL (b) Connect the left and right engine magnetic pick-up cables (two pin) to channels A and B respectively. C. Pre-test notes (1) The propellers must be balanced to within.2 IPS at 1450 PRPM and 2500 lb.ft torque. (2) Observe starter limitations between tests. (3) The optimum test results are realised when the PHAZOR light flashes constantly around the face of the clock with the IPS indicator at less than.2. D. Balancer unit controls Refer to Figure 210. (1) Set the controls as follows:- (a) FUNCTION switch - set to `A' for left propeller or `B' for right propeller. (b) INTERRUPTER LOGIC - set to SINGLE. (c) MAGNETIC PICK-UP switch - set to INDEPENDENT. (d) R.P.M. RANGE - set to X10. (e) R.P.M. TUNE dial - set to 150. E. Balance a propeller (1) Start the engine. Refer to 71-00-00, pb1. (2) Set P.R.P.M. to 1450 and torque to 2500 lbs.ft. (3) Close circuit breaker (No.222 for FERRY FUEL on distribution panel 2D if recommended supply is used). (4) Press TEST button to synchronie the 12.00 o'clock position light in the PHAZOR with the accelerometer position. Release test button. NOTE: If the propeller is out of balance, one light will flash constantly. (5) Observe which light(s) in the phaor is (are) flashing and tune the balancer unit as follows:- (a) Press the VERIFY TUNE button and check if the position of the light(s) change. (b) If the flashing light(s) in the phaor changes, adjust the R.P.M. TUNE (with the VERIFY TUNE button pressed) until flashing light(s) return(s) to the original position(s) as in (5) Page 220
Balancer unit controls - Model 177M-6B Figure 210 Page 221
SD3-60 AIRCRAFT MAINTENANCE MANUAL (c) Release the VERIFY TUNE button and check that the light position is unchanged. (d) Repeat (b) until the conditions detailed in (c) are met. (6) Record the 'out of balance' clock position and the amount of imbalance from the IPS scale on the balance chart. Refer to Figure 211. NOTE: If the IPS reading is off scale, press PUSH FOR SCALE 2 button. The graduations will then read 0 to 10 instead of 0 to 1.0. (7) Stop engine - refer to Chap.71. (8) Add weights as appropriate to correct the imbalance. Refer to Figure 211. (9) Retest as detailed in E(1) thru (8) until propeller balance is within.2 IPS. (10) Set the function switch to B and balance the propeller of the right engine as detailed in E(1) thru (9). F. Restore the aircraft (1) Open circuit breaker No.222 (2) Remove access panel 430AT (3) Disconnect cables and remove accelerometer, magnetic pick up and interrupter (4) Refit access panels. Page 222
Balance chart (5 bladed propeller) Figure 211 Page 223