Attachment 34_Critical Safety Item List.xlsx

Sheet1

The Lee Jet Plug is integral to the Piston in the Cylinder Assembly of the Propeller. High pressure oil is supplied to the Cylinder that causes the Piston/Crosshead to move and transmit the force to rotate the De-Iced Blade Assemblies. The Lee Jet Plug is used to seal the drilled passageway in the Piston Assembly. If the Plug fails, fine pitch oil can leak into the coarse pitch side and vice versa leading to unpredictable Blade angles. The Propeller can be moved to feather in this scenario and the Blade that has lost control will be driven to feather by the Counterweight. 12/18/2025 6:04:00 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

This Seal installs on the outside diameter of the Piston Assembly used in the Cylinder of the Propeller. The Seal prevents leakage of fine to coarse pitch (or coarse to fine) hydraulic oil. This leakage could result in unpredictable Blade angle changes. 12/18/2025 6:03:58 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Outer Race is part of the Bearing Assemblies used to change pitch on the De-Iced Blade Assemblies. The Inner Race installs on the Blade Root and the Outer Race installs in the Hub Assembly. The Outer Race is subject to corrosion pitting or indentions caused by debris or bad brinelling. Damaged Races can cause the Blade to bind at an undesired angle and has the potential for a catastrophic end effect, classifying this part as CSI. 12/18/2025 6:03:58 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Inner Race is part of the Bearing Assemblies used to change pitch on the De-Iced Blade Assemblies. The Inner Race installs on the Blade Root and the Outer Race installs in the Hub Assembly. The Inner Race is subject to corrosion pitting or indentions caused by debris or bad brinelling. Damaged Races can cause the Blade to bind at an undesired angle and has the potential for a catastrophic end effect, classifying this part as CSI. 12/18/2025 6:03:58 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

To change pitch, each de-iced blade assembly turns on two, taper roller bearing assemblies. Both bearings are the single row type with a two piece inner ring for easy removal. The inner races install on the blade root and the outer races install in the hub assembly. A ring nut holds the outer race of the outboard bearing assembly and is satisfied with a locking plate. This cage and taper roller is used on the Outboard Bearing Assembly. Damaged Bearings can cause the Blade to bind at an undesired angle and has the potential for a catastrophic end effect, classifying this part as CSI. 12/18/2025 6:03:58 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Outer Race is part of the Bearing Assemblies used to change pitch on the De-Iced Blade Assemblies. The Inner Race installs on the Blade Root and the Outer Race installs in the Hub Assembly. The Outer Race is subject to corrosion pitting or indentions caused by debris or bad brinelling. Damaged Races can cause the Blade to bind at an undesired angle and has the potential for a catastrophic end effect, classifying this part as CSI. 12/18/2025 6:03:58 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Inner Race is part of the Bearing Assemblies used to change pitch on the De-Iced Blade Assemblies. The Inner Race installs on the Blade Root and the Outer Race installs in the Hub Assembly. The Inner Race is subject to corrosion pitting or indentions caused by debris or bad brinelling. Damaged Races can cause the Blade to bind at an undesired angle and has the potential for a catastrophic end effect, classifying this part as CSI. 12/18/2025 6:03:58 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

To change pitch, each de-iced blade assembly turns on two, taper roller bearing assemblies. Both bearings are the single row type with a two piece inner ring for easy removal. The inner races install on the blade root and the outer races install in the hub assembly. A ring nut holds the outer race of the outboard bearing assembly and is satisfied with a locking plate. This cage and taper roller is used on the Inboard Bearing Assembly. Damaged Bearings can cause the Blade to bind at an undesired angle and has the potential for a catastrophic end effect, classifying this part as CSI. 12/18/2025 6:03:58 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

There are six De-Iced Blade Assemblies for each Propeller. The Blades are made from a composite skin with a mixture of glass and carbon fiber. A carbon spar on each blade face gives primary strength. The blades have a polyurethane foam core and cuff. A polyurethane spraycoat gives protection to the blade surface. A lightning conductor braid moulded alnong the ful length of each de-iced blade assembly attaches to the outer sleeve. Lead wool is installed as necessary for balancing. Two Taper Roller Bearing Assemblies are used to change pitch. Multiple failure modes exist for the De-Iced Blade Assemblies, which could potentially degrade feathering and pitch change operations making the Assembly CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

Stage 3 is the root end of the Blade Assembly and is a sub-component to the De-Iced Blade Assembly. The Blade De-Icer is bonded to the Stage 3 Blade Assembly using PR1440-B2 sealing compound. The Operating Pin is joined to Stage 3 with a joining compound. Because the Stage 3 Assembly contains the Operating Pin Assembly, which is critical to Blade rotation, this Assembly is a CSI component. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

There are six De-Iced Blade Assemblies for each Propeller. The Blades are made from a composite skin with a mixture of glass and carbon fiber. A carbon spar on each blade face gives primary strength. The blades have a polyurethane foam core and cuff. A polyurethane spraycoat gives protection to the blade surface. A lightning conductor braid moulded alnong the ful length of each de-iced blade assembly attaches to the outer sleeve. Lead wool is installed as necessary for balancing. Two Taper Roller Bearing Assemblies are used to change pitch. Multiple failure modes exist for the De-Iced Blade Assemblies, which could potentially degrade feathering and pitch change operations making the Assembly CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Hub Assembly is an aluminum housing with front and rear hub halves. The halves a held together with eighteen bolts, washers, and self-locking nuts. Fifteen bolts and three drive dowels install in the installation face of the rear hub half. A bush, seal kit, and a retaining ring install in an internal diameter of the front and rear halves. There are six blade locations for de-iced blade assemblies and each has a PTFE lip seal to prevent leakage of bearing grease. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

Stage 3 is the root end of the Blade Assembly and is a sub-component to the De-Iced Blade Assembly. The Blade De-Icer is bonded to the Stage 3 Blade Assembly using PR1440-B2 sealing compound. The Operating Pin is joined to Stage 3 with a joining compound. Because the Stage 3 Assembly contains the Operating Pin Assembly, which is critical to Blade rotation, this Assembly is a CSI component. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

There are six De-Iced Blade Assemblies for each Propeller. The Blades are made from a composite skin with a mixture of glass and carbon fiber. A carbon spar on each blade face gives primary strength. The blades have a polyurethane foam core and cuff. A polyurethane spraycoat gives protection to the blade surface. A lightning conductor braid moulded alnong the ful length of each de-iced blade assembly attaches to the outer sleeve. Lead wool is installed as necessary for balancing. Two Taper Roller Bearing Assemblies are used to change pitch. Multiple failure modes exist for the De-Iced Blade Assemblies, which could potentially degrade feathering and pitch change operations making the Assembly CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

There are six De-Iced Blade Assemblies for each Propeller. The Blades are made from a composite skin with a mixture of glass and carbon fiber. A carbon spar on each blade face gives primary strength. The blades have a polyurethane foam core and cuff. A polyurethane spraycoat gives protection to the blade surface. A lightning conductor braid moulded alnong the ful length of each de-iced blade assembly attaches to the outer sleeve. Lead wool is installed as necessary for balancing. Two Taper Roller Bearing Assemblies are used to change pitch. Multiple failure modes exist for the De-Iced Blade Assemblies, which could potentially degrade feathering and pitch change operations making the Assembly CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Counterweight Assembly is attached to the outer sleeve of each De-Iced Blade Assembly by six Bolts and Washers. The Bolts are safetied with lockwire. The Counterweight Assembly has a heavy metal Counterweight which attaches to a Counterweight Arm with three Bolts and Washers. The Counterweight is designed such that the centrifugal force on the Counterweight exerts a twisting moment about the blade pitch change axis to overcome blade loads that would drive the blades to fine pitch (reverse) in the event of a hydraulic failure. Combined with a hidden failure that causes a hydraulic failure, a Counterweight failure could result in a catastrophic end effect, classifying it as CSI. 12/18/2025 6:03:55 PM : USAF Recommendation: Retain 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN

There are six De-Iced Blade Assemblies for each Propeller. The Blades are made from a composite skin with a mixture of glass and carbon fiber. A carbon spar on each blade face gives primary strength. The blades have a polyurethane foam core and cuff. A polyurethane spraycoat gives protection to the blade surface. A lightning conductor braid moulded alnong the ful length of each de-iced blade assembly attaches to the outer sleeve. Lead wool is installed as necessary for balancing. Two Taper Roller Bearing Assemblies are used to change pitch. Multiple failure modes exist for the De-Iced Blade Assemblies, which could potentially degrade feathering and pitch change operations making the Assembly CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

There are six De-Iced Blade Assemblies for each Propeller. The Blades are made from a composite skin with a mixture of glass and carbon fiber. A carbon spar on each blade face gives primary strength. The blades have a polyurethane foam core and cuff. A polyurethane spraycoat gives protection to the blade surface. A lightning conductor braid moulded alnong the ful length of each de-iced blade assembly attaches to the outer sleeve. Lead wool is installed as necessary for balancing. Two Taper Roller Bearing Assemblies are used to change pitch. Multiple failure modes exist for the De-Iced Blade Assemblies, which could potentially degrade feathering and pitch change operations making the Assembly CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

Stage 3 is the root end of the Blade Assembly and is a sub-component to the De-Iced Blade Assembly. The Blade De-Icer is bonded to the Stage 3 Blade Assembly using PR1440-B2 sealing compound. The Operating Pin is joined to Stage 3 with a joining compound. Because the Stage 3 Assembly contains the Operating Pin Assembly, which is critical to Blade rotation, this Assembly is a CSI component. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

There are six De-Iced Blade Assemblies for each Propeller. The Blades are made from a composite skin with a mixture of glass and carbon fiber. A carbon spar on each blade face gives primary strength. The blades have a polyurethane foam core and cuff. A polyurethane spraycoat gives protection to the blade surface. A lightning conductor braid moulded alnong the ful length of each de-iced blade assembly attaches to the outer sleeve. Lead wool is installed as necessary for balancing. Two Taper Roller Bearing Assemblies are used to change pitch. Multiple failure modes exist for the De-Iced Blade Assemblies, which could potentially degrade feathering and pitch change operations making the Assembly CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

There are six De-Iced Blade Assemblies for each Propeller. The Blades are made from a composite skin with a mixture of glass and carbon fiber. A carbon spar on each blade face gives primary strength. The blades have a polyurethane foam core and cuff. A polyurethane spraycoat gives protection to the blade surface. A lightning conductor braid moulded alnong the ful length of each de-iced blade assembly attaches to the outer sleeve. Lead wool is installed as necessary for balancing. Two Taper Roller Bearing Assemblies are used to change pitch. Multiple failure modes exist for the De-Iced Blade Assemblies, which could potentially degrade feathering and pitch change operations making the Assembly CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

There are six De-Iced Blade Assemblies for each Propeller. The Blades are made from a composite skin with a mixture of glass and carbon fiber. A carbon spar on each blade face gives primary strength. The blades have a polyurethane foam core and cuff. A polyurethane spraycoat gives protection to the blade surface. A lightning conductor braid moulded alnong the ful length of each de-iced blade assembly attaches to the outer sleeve. Lead wool is installed as necessary for balancing. Two Taper Roller Bearing Assemblies are used to change pitch. Multiple failure modes exist for the De-Iced Blade Assemblies, which could potentially degrade feathering and pitch change operations making the Assembly CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

There are six De-Iced Blade Assemblies for each Propeller. The Blades are made from a composite skin with a mixture of glass and carbon fiber. A carbon spar on each blade face gives primary strength. The blades have a polyurethane foam core and cuff. A polyurethane spraycoat gives protection to the blade surface. A lightning conductor braid moulded alnong the ful length of each de-iced blade assembly attaches to the outer sleeve. Lead wool is installed as necessary for balancing. Two Taper Roller Bearing Assemblies are used to change pitch. Multiple failure modes exist for the De-Iced Blade Assemblies, which could potentially degrade feathering and pitch change operations making the Assembly CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Counterweight Assembly is attached to the outer sleeve of each De-Iced Blade Assembly by six Bolts and Washers. The Bolts are safetied with lockwire. The Counterweight Assembly has a heavy metal Counterweight which attaches to a Counterweight Arm with three Bolts and Washers. The Counterweight is designed such that the centrifugal force on the Counterweight exerts a twisting moment about the blade pitch change axis to overcome blade loads that would drive the blades to fine pitch (reverse) in the event of a hydraulic failure. Combined with a hidden failure that causes a hydraulic failure, a Counterweight failure could result in a catastrophic end effect, classifying it as CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Counterweight Assembly is attached to the outer sleeve of each De-Iced Blade Assembly by six Bolts and Washers. The Bolts are safetied with lockwire. The Counterweight Assembly has a heavy metal Counterweight which attaches to a Counterweight Arm with three Bolts and Washers. The Counterweight is designed such that the centrifugal force on the Counterweight exerts a twisting moment about the blade pitch change axis to overcome blade loads that would drive the blades to fine pitch (reverse) in the event of a hydraulic failure. Combined with a hidden failure that causes a hydraulic failure, a Counterweight failure could result in a catastrophic end effect, classifying it as CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Counterweight Assembly is attached to the outer sleeve of each De-Iced Blade Assembly by six Bolts and Washers. The Bolts are safetied with lockwire. The Counterweight Assembly has a heavy metal Counterweight which attaches to a Counterweight Arm with three Bolts and Washers. The Counterweight is designed such that the centrifugal force on the Counterweight exerts a twisting moment about the blade pitch change axis to overcome blade loads that would drive the blades to fine pitch (reverse) in the event of a hydraulic failure. Combined with a hidden failure that causes a hydraulic failure, a Counterweight failure could result in a catastrophic end effect, classifying it as CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Piston installs on the end of the Crosshead Shaft. It moves in the Cylinder between the internal face of the Cylinder and the abutment face of the Hub Assembly. A PTFE Cap Seal makes a seal against the internal diameter of the Cylinder. A nut holds the Piston against a shoulder on the Crosshead Shaft. An Adjusting Washer installs between the Piston and the Flange. The Adjusting Washer controls the feather angle of the Propeller Blades. If the Piston is cracked or out of round, leakage and binding within the Cylinder are possible, which can potentially result in a catastrophic end effect, classifying the Piston as CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The six sided Crosshead Yoke is fitted inside of the Hub Assembly onto a steel Crosshead Shaft and is locked together by a large retaining nut. The inside faces of both flanges of the Yoke are tungsten carbide coated to prevent wear from the operating pin movement, and fitted on two sides of the Yoke, 180 degrees apar and locatd by two dowels are two nylatron sliding blocks which prevent rubbing of the blade root on the crosshead. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Cylinder Assembly is attached to the front of the Hub Assembly of the Propeller with twelve capscrews and spacers. An O-Ring seal makes a seal between the Cylinder and Hub Assembly. A Cover installs in an internal diamerter in the front of the Cylinder with six bolts and washers. An O-Ring Seal makes a seal between the Cover and the Cylinder. A failure of the Cylinder, including cracking or warping, could cause leakage of hydraulic oil and result in a catastrophic end effect. The Cylinder is therefore classified as CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Counterweight Assembly is attached to the outer sleeve of each De-Iced Blade Assembly by six Bolts and Washers. The Bolts are safetied with lockwire. The Counterweight Assembly has a heavy metal Counterweight which attaches to a Counterweight Arm with three Bolts and Washers. The Counterweight is designed such that the centrifugal force on the Counterweight exerts a twisting moment about the blade pitch change axis to overcome blade loads that would drive the blades to fine pitch (reverse) in the event of a hydraulic failure. Combined with a hidden failure that causes a hydraulic failure, a Counterweight failure could result in a catastrophic end effect, classifying it as CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Dowel Drives are used with fifeteen Stepped Studs in the rear half Hub to attach it to the Engine Flange Iterface. The steel threaded studs are inserted from the inner wall of the Hub. Later Hubs are fitted with through bolts retained by a steel ring to further reduce stress levels in the Hub and extend its service life. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

Fifeteen Stepped Studs are used in the rear half Hub to attach it to the Engine Flange Interface. The steel threaded studs are inserted from the inner wall of the Hub. Later Hubs are fitted with through bolts retained by a steel ring to further reduce stress levels in the Hub and extend its service life. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Hub is an aluminum housing with front and rear hub halves. The halves a held together with eighteen bolts, washers, and self-locking nuts. Fifteen bolts and three drive dowels install in the installation face of the rear hub half. A bush, seal kit, and a retaining ring install in an internal diameter of the front and rear halves. The Hub halves remain together as a matched pair throughout the operating life of the propeller. There are six blade locations for de-iced blade assemblies and each has a PTFE lip seal to prevent leakage of bearing grease. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Hub is an aluminum housing with front and rear hub halves. The halves a held together with eighteen bolts, washers, and self-locking nuts. Fifteen bolts and three drive dowels install in the installation face of the rear hub half. A bush, seal kit, and a retaining ring install in an internal diameter of the front and rear halves. The Hub halves remain together as a matched pair throughout the operating life of the propeller. There are six blade locations for de-iced blade assemblies and each has a PTFE lip seal to prevent leakage of bearing grease. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Hub is an aluminum housing with front and rear hub halves. The halves a held together with eighteen bolts, washers, and self-locking nuts. Fifteen bolts and three drive dowels install in the installation face of the rear hub half. A bush, seal kit, and a retaining ring install in an internal diameter of the front and rear halves. The Hub halves remain together as a matched pair throughout the operating life of the propeller. There are six blade locations for de-iced blade assemblies and each has a PTFE lip seal to prevent leakage of bearing grease. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Hub is an aluminum housing with front and rear hub halves. The halves a held together with eighteen bolts, washers, and self-locking nuts. Fifteen bolts and three drive dowels install in the installation face of the rear hub half. A bush, seal kit, and a retaining ring install in an internal diameter of the front and rear halves. The Hub halves remain together as a matched pair throughout the operating life of the propeller. There are six blade locations for de-iced blade assemblies and each has a PTFE lip seal to prevent leakage of bearing grease. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Counterweight Arm holds the Counterweight to the De-Iced Blade Assembly. The Counterweight is designed such that the centrifugal force on the Counterweight exerts a twisting moment about the blade pitch change axis to overcome blade loads that would drive the blades to fine pitch (reverse) in the event of a hydrualic failure. The Arm can fail from corrosion or wear resulting in a fracture. Loss of the Counterweight, when coupled with loss of hydraulic pressure, results in a catastrophic end effect, classifying the Arm as CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Counterweight Arm holds the Counterweight to the De-Iced Blade Assembly. The Counterweight is designed such that the centrifugal force on the Counterweight exerts a twisting moment about the blade pitch change axis to overcome blade loads that would drive the blades to fine pitch (reverse) in the event of a hydrualic failure. The Arm can fail from corrosion or wear resulting in a fracture. Loss of the Counterweight, when coupled with loss of hydraulic pressure, results in a catastrophic end effect, classifying the Arm as CSI. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Hub is an aluminum housing with front and rear hub halves. The halves a held together with eighteen bolts, washers, and self-locking nuts. Fifteen bolts and three drive dowels install in the installation face of the rear hub half. A bush, seal kit, and a retaining ring install in an internal diameter of the front and rear halves. The Hub halves remain together as a matched pair throughout the operating life of the propeller. There are six blade locations for de-iced blade assemblies and each has a PTFE lip seal to prevent leakage of bearing grease. 12/18/2025 6:03:55 PM : USAF Comment: No NSN / NIIN USAF Review: Retain

The Hub is an aluminum housing with front and rear hub halves. The halves a held together with eighteen bolts, washers, and self-locking nuts. Fifteen bolts and three drive dowels install in the installation face of the rear hub half. A bush, seal kit, and a retaining ring install in an internal diameter of the front and rear halves. The Hub halves remain together as a matched pair throughout the operating life of the propeller. There are six blade locations for de-iced blade assemblies and each has a PTFE lip seal to prevent leakage of bearing grease.