Propeller Construction


TTP
B1-L3
ATA61A
Cessna 172
B2-L1


 Two bladed, fixed pitch metal propeller are manufactured of one-piece anodized Al alloy.
Identification hub of each propeller is stamped with the complete model number, serial number, TC number, production certification number,and the number of times the propeller has been reconditioned. The complete model number is a combination of the basic model number and suffix numbers to indicate the propeller diameter and pitch.
Propeller Model Designation is steel stamped on the forward/camber side/face of the propeller hub.
Overhaul. a complete tear-down and reassembly which is not necessarily applicable to a FPP. The terms "overhaul" and "reconditioning" are sometimes used synonymously for a fixed pitch propeller. The overhaul of a propeller requires the propeller to be inspected for conformity to a fixed set of dimensions and is required on a predetermined interval while reconditioning can occur on an as needed basis.
Reconditioning. The repair of blade damage caused by erosion or striking small objects during normal operation. The propeller shall be fluorescent dye penetrant inspected, refinished, and rebalanced. Reconditioning is accomplished on an irregular basis as necessary and required.
Repair. The correction on an irregular basis as necessary, of damage that has occurred to the propeller. The amount, degree, and extent of damage determines whether or not the propeller can be repaired without refinishing or removing the propeller from the engine. If a propeller is bent or twisted, the repair is major and reconditioning or overhaul of the propeller must be accomplished.
Frequency of Overhaul. Refer  TBO. Propellers shall also be overhauled or repaired as required for blade surface conditions. The propeller mounting bolt torque should be checked at least once a year. Propeller mounting bolts must be magnetic particle inspected in accordance with ASTM E-1444 or replaced whenever the propeller is removed from the engine.

PROPELLER INSTALLATION INSTRUCTIONS               A-2230
1. Lightly oil O-ring and hub bore surfaces only.
2. Propeller face, stud and nut threads, engine flange holes, and both flange surfaces must be clean and dry.
3. Torque nuts 65 to 55 lb-ft.

Blade SN Information  is stamped on the hub
(1) Blade serial numbers assigned before 1980:
(a) Prior to 1980, no calendar date information was encoded in the propeller serial number.
(b) Initially, the serial number was a 4 digit number and the numbers were assigned in
ascending order.
(c) Eventually, the serial number became a 7 digit number.
(d) Not all serial numbers are sequential, there are large breaks between assigned propeller
serial numbers.
(2) Blade serial numbers assigned after 1980 and before June 15, 2000:
(a)First letter represents the year of manufacture.
(b)Second letter represents  month of manufacture.
(c)Following digits represent number of  blade manufactured during the month of manufacture.
(3) Blade serial numbers assigned after June 15, 2000:
(a) First or first and second letters represent the year of manufacture.
(b) The second, or third, letters represent the month of manufacture.
(c) The first two digits represent a reference forging model.
(d) The following digits represent the number of the blade manufactured during the month of
manufacture.
Service Bulletins and Service Letters 
A. Alert Service Bulletin are technical documents that provide instructions and, if applicable, part information for the incorporation of an installation, modification, or repair to a specific propeller or propeller component. Alert Service Bulletins are used to announce mandatory special product inspection criteria and modifications, revised maintenance information and/or revised operational information which has been determined to be critical for the continued safe and reliable performance of the propeller, or propeller component.
 B. Service Bulletin are technical documents that provide instructions and, if applicable, part information for the incorporation of an installation, modification, or repair to a specific propeller or propeller component. Service Bulletins are used to announce special product inspection criteria and modifications, revised maintenance information and/or revised operational information which has been determined to be critical for the continued safe and reliable performance of the propeller, or propeller component. 
C. Service Letter  are used to announce support and service information. 
D. Special Service Project (SSP's) are similar to service bulletins and are used to announce special product inspection criteria and modifications, revised maintenance information and/or revised operational information which is intended to assist in improving propeller safety, reliability, durability and/or performance. SSP's typically contain similar information and/or headings as service bulletins, but are often tailored for special situations and/or conditions or logistical requirements that may affect only a limited number of propellers. One additional heading that can be found on a SSP is the heading titled "Duration". The Duration heading provides an expiration date for the SSP when used.

SB 227B    Propeller Installation Mounting Torque : All McCauley  prop
SB137AF  TIME BETWEEN OVERHAUL (TBO)
SB 240E    : Inspection of Propeller Blade for Cracking  1A170E/JHA[XXXX],

571018 Wing structure external. Make sure you inspect these areas: 1. Skin with emphasis
at skin overlaps and under access panels. 2. Rear spar upper and lower caps. 3.Rear spar web.
611002 Spinner and Spinner Bulkhead - Remove spinner, wash, and inspect for cracks and
fractures. B 05-12-02 110
611003 Propeller Blades - Inspect for cracks, dents, nicks, scratches, erosion, corrosion, or other damage. A 05-12-01 110

611004 Propeller Hub - Check general condition.
611005 Propeller Mounting - Check for security of installation. A 05-12-01 110
611006 Propeller Mounting Bolts - Inspect mounting bolts and safety wire for signs of looseness.
                                Propeller and Spinner 
Remove the Propeller and Spinner 
WARNING: Exercise care when working with the propeller. Ensure magneto switch is in
the off position before turning propeller.
(1) Remove the cowling and nose cap.
(2) Remove screws securing the spinner to the forward and aft bulkheads. Remove the spinner.
(3) Cut and discard safety wire from the propeller mounting bolts.
(4) Remove the mounting bolts, forward bulkhead, propeller, aft bulkhead and spacer from crankshaft.
NOTE: A dowel pin holds the propeller, aft bulkhead and spacer together when removed.
(5) The propeller mounting bolts must be magnetic particle inspected, refer to ASTM E-1414 or liquid penetrant inspected, refer to ASTM E-1417, or replaced at every overhaul. The propeller mounting
bolts must be replaced when the propeller is involved in a blade strike.
(6) Remove the spacer and the aft bulkhead from the propeller.
(a) Support the propeller by setting it between two sand filled bags placed as close to the hub as possible with the spacer down. Allow two (2) inches of clearance for the spacer and aft bulkhead to separate from the hub.
(b) Select a rod of proper diameter and is six (6) inches long. Insert rod into propeller hub dowel pin holes. Using a hammer, lightly tap dowels in a alternating pattern to free the spacer and bulkhead from propeller hub. The dowels will remain in the spacer.
(c) If the tapered end of dowels were installed in the propeller hub, remove dowels from spacer by inserting the rod into dowel pin holes in spacer. Using a hammer, lightly tap dowels in a alternating pattern to remove dowels from spacer.
B. Aft bulkhead and spacer assembly.
CAUTION: The spacer and propeller are balanced as a pair and must be installed together. Do not exchange spacers or propellers from other airplanes.
(1) Position spacer on a arbor press table with hub mating surface facing up.
(2) If dowels were removed from spacer, install dowels with tapered end into spacer.
(a) Lightly oil each dowel and press into spacer.
(b) Engage dowel into spacer enough to hold dowel firmly. Extension of both dowels above face of spacer must be the same after pressing.
NOTE: Final dowel location will be made when spacer is installed in propeller hub.
(c) Position propeller hub on arbor press table with spacer mating surface facing up.(d) Place bulkhead over hub aligned with dowel holes.
(e) Align serial number on spacer with serial number on propeller hub.
(f) Press spacer down against hub and allow the bulkhead to rotate against the dowels for
adjustment.
C. Install the Propeller and Spinner.
CAUTION: The spacer and propeller are balanced as a pair and must be installed together. Do not exchange spacers or propellers from other airplanes.
(1) Clean the mating surfaces and install the spacer, propeller and bulkheads to crankshaft. Make sure the serial number stamped on the side of the spacer lines up with either of the propeller blades.
(2) Clock the propeller as follows:
(a) Find the top center (TC) mark on the aft face of the starter ring gear.
(b) Align one of the propeller blades with the TC mark.
(c) Rotate the propeller clockwise, looking from in front of the airplane until the bolt holes align.
(3) Install the spacer, aft bulkhead, propeller and forward bulkhead to crankshaft with mounting bolts finger tight.
(4) Install spinner over bulkheads and install screws in forward bulkhead finger tight.
(5) Rotate the aft bulkhead until the spinner screws can be installed with little effort.
(6) Identify on the propeller, spinner, forward and aft bulkheads index marks for screw alignment.
(7) Carefully remove spinner so the forward and aft bulkhead remains in the same aligned position.
(8) Secure propeller assembly using the propeller bolts and washers. Tighten the mounting bolts in a crossing pattern to 660-780 inch-pounds dry (55-65 foot-pounds dry). Safety wire the mounting bolts..

PROPELLER INSTALLATION INSTRUCTIONS A-2230
1. Lightly oil O-ring and hub bore surfaces only.
2. Propeller face, stud and nut threads, engine flange holes, and both flange surfaces must be clean and dry.
3. Torque nuts 65 to 55 lb-ft.

D. Install spinner in same position with index marks

Check the spinner to aft bulkhead clearance.
(1) If not removed, remove upper cowling and upper nosecap. 
(2) Using a 0.03 inch feeler gauge insert gauge between spinner and aft bulkhead to ensure the gap is 0.03 inches or less. If a gauge is not available, fabricate a gauge from phenolicaluminum or steel that is 0.5 inches wide by 0.03 inches thick and 2.0 inches long.(3) Replacement of the Aft Bulkhead will be required if gap is more than 0.03 inches.
(4) Adjust alternator belt tension.
(5) Install nosecap and cowling.
F. Check the spinner to propeller clearance.
(1) Clearance between the spinner and propeller must be a minimum of 0.10 inch.
(2) If clearance is not a minimum of 0.10 inch, remove and adjust the spinner.

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