Thursday, April 25, 2013

McCauley Fixed Pitch Propeller Removal


        The following instructions are general in nature. The aircraft maintenance manual or STC installation instructions should always be consulted for any specialized procedures applicable to a specific aircraft. Various spinner arrangements not manufactured by McCauley may be used which require additional procedures.
        In the following instructions, installation of propeller is based on the assumption that a McCauley spinner will be used. If a spinner is not used or if the spinner is not manufactured by McCauley,omit those steps which apply to the spinner.
              WARNING: Verify that engine magnetos have been grounded prior to approaching the propeller.
Spinner Assembly Removal
       (1) Make an alignment mark on the spinner shell, aft bulkhead and adjacent blade with a felt tip pen. This index mark ensures accurate restoration of spinner shell position to lessen the distortion of any dynamic balance previously performed on the propeller assembly.
       (2) Remove screws and washers from the spinner and fillet assemblies (if fillet assemblies are installed).
       (3) Remove spinner from the bulkhead and fillet assemblies (if fillet assemblies are installed).
       (4) If required, remove screws and washers attaching fillets to bulkhead and remove fillets. Identify location of each fillet to the bulkhead.
                NOTE: On some spinner assemblies, the fillets are riveted in place and cannot be removed from the bulkhead assembly.
                     Propeller Removal
       (1) Remove cowling as required for access to mounting nuts.
NOTE: Not all propellers use nuts to secure the propeller mounting bolts.
       (2) Remove the safety wire from the bolts if installed.
       (3) Break the torque on the propeller mounting bolts and nuts.
       (4) Support the propeller, remove the mounting bolts and remove the propeller from the engine crankshaft flange.
              NOTE: Some propeller spinner front supports use the propeller mounting bolts to hold the front spinner support in position on the propeller.
              NOTE: If you have not removed or installed the propeller and spinner assembly from the engine before, the use of a propeller sling and hoist is recommended to prevent
accidental damage to the propeller. If a hoist is not available, the propeller may be
supported and lifted by hand. Make sure an adequate number of people are available
to support the propeller if a hoist is not used.
     (5) Place the propeller on a suitable work surface.
                          Spacer Removal (If Installed).
     (1) For all fixed pitch propellers (except 1A162 model propellers) with a spacer installed, 
            NOTE: The following procedure should be used to remove a rear spinner bulkhead, when it is clamped between a spacer and the propeller hub.
            (a) Support the propeller by nesting it between two shot or sand-filled bags.
            (b) Put the supports as close to the hub as possible with the spacer down facing the bench or table top.
            (c) Make sure you allow sufficient clearance (approximately 2 inches) for the spacer to separate from the hub.
           (d) Select a punch with the proper diameter, approximately 6 inches long, and insert it into the dowel pin hole.
           (e) Alternately tap one dowel and then the other with light hammer blows to free the spacer from the propeller hub.
     (2) For 1A162 model propellers with a spacer installed, 
(a) Tool Fabrication
        NOTE: The spacer removal tool can be fabricated locally or a tool, part number A-8029,can be purchased from McCauley.
      1 Use a steel bar that is at least 0.250 inch (6.35 mm) thick and 2.00 inches (51.00 mm)
wide and 6.0 inches (152.0 mm) long.
      2 Drill two 0.250 inch (6.35 mm) holes in the steel bar that are 2.875 inches apart,
+0.020 or -0.020 inches (73.03 mm, +0.5 mm or -0.5 mm) and 1.438 inches, +0.020
or -0.020 inches (36.53 mm, +0.5 mm or -0.5 mm) from the center of the steel bar.
(b) Remove the propeller and spacer assembly from the airplane.
(c) Spacer Removal Procedure 
      1 Attach the spacer removal tool to the propeller spacer using two 0.250 inch diameter
bolts with UNC-3A threads.
NOTE: Bolts to be used should be made of steel, 0.250 inch in diameter, have a
UNC-3A thread and the grip length sized tomatch the thickness of the steel
bar. For steel bars that are 0.250 inch (6.35 mm) thick, a MS20074-04-06
bolt is an appropriate sized bolt for this application.
     2 Position the propeller and spacer assembly under an arbor press or similar tool 
     3 Place two propeller mounting bolts or equivalent sized steel dowels in the propeller and spacer assembly. The bolts or dowels that are used to push the spacer from the propeller must be of equal length.
                   CAUTION: Do not use bolts that will be returned to service for this procedure. This procedure can damage the threads of propeller mounting bolts.
     4 Make sure there is at least 2.00 inches (50 mm) clearance between the spacer removal tool attached to the propeller spacer and the work surface supporting the sandbags.
     5 Using an arbor press or similar tool, push the bolts or dowels down to remove the
spacer from the propeller.
     6 Once the spacer is separated from the propeller, remove the 0.250 inch bolts and the
spacer removal tool from the spacer.

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