Instructions for Continued Airworthiness Dual Cargo Hook System

25.17.2 Secondary Attach Point Re-installation, Section 25, Page 16 25.17.3 Cargo Hook Orientation, Section 25, Page 17 25.17.4 Cargo Hook Attachment Hardware, Section 25, Page 18 25.17.5 Cargo Hook Attachment w/ Pin Load Cell, Section 25 Page 18 25.17.6 Slave Cylinder Assembly Installation, Section 25 Page 19 25.17.7 Hydraulic Hose & Electrical Harness Routing, Section 25 Page 20 25.17.8 Hose and Harness Routing from Secondary Hook, Section 25 Page 21 25.17.9 External Hose and Harness Routing, Section 25 Page 22 25.17.10 Hydraulic Release System Installation, Section 25 Page 24 25.17.11 Lever Adjustment, Section 25 Page 25 25.17.12 Relay Re-installation, Section 25 Page 26 Instructions for Continued Airworthiness 123-048-00 Page ix Revision 2 02/25/20 Tables 5.2.1 Cargo Hook Installation Parts, Section 5 Page 5 5.2.2 Dual Cargo Hook Suspension Inspection Criteria, Section 5 Page 6 5.3.1 Long Line Kit Parts, Section 5 Page 8 5.3.2 Long Line Kit Inspection Criteria, Section 5 Page 12 11.1 Cargo Hook Kit Placards, Section 11 Page 1 25.5.1 Component Weights and CGs, Section 25 Page 4 25.15.1 Troubleshooting, Section 25 Page 5 Instructions for Continued Airworthiness 123-048-00 Page x Revision 2 02/25/20 THIS PAGE INTENTIONALLY LEFT BLANK Instructions for Continued Airworthiness 123-048-00 Revision 3 00-00-00 Page 1 08/17/21 Section 0 Introduction 0.4 Scope The following information is necessary to carry out the service, maintenance, and inspection of the Dual Cargo Hook System P/N 200- 448-00 and P/N 200-448-01, Long Line Kit P/N 200-449-XX, and optional Pin Load Weigh Kit P/Ns 200-383-00 and 200-383-01. See Section 25.2 for a detailed description of these P/Ns. 0.5 Purpose The purpose of this Instructions for Continued Airworthiness (ICA) manual is to provide the information necessary to inspect, service, and maintain the dual cargo hook system and long line kit in an airworthy condition. 0.6 Arrangement This manual contains instructions for the service, maintenance, inspection and operation of the part numbers listed above and as installed on MD Helicopters (MDHI) 369D, 369E, 369F, 369FF, 500N and 600N model helicopters. The manual is arranged in the general order that maintenance personnel would use to maintain the Dual Cargo Hook System and Long Line Kit in service. The arrangement is: Section 0 Introduction. Section 4 Airworthiness Limitations Section 5 Inspection and Overhaul Schedule Section 11 Placards and Markings Section 12 Servicing Section 25 Equipment and Furnishings 0.7 Applicability These Instructions for Continued Airworthiness are applicable to Dual Cargo Hook System P/Ns 200-448-00 and 200-448-01, Long Line Kit P/N 200-449-XX, and Pin Load Weigh Kit P/Ns 200-383-00 and 200-383-01 for the MD Helicopters 369 series, 500N, and 600N model helicopters. Refer to the appropriate MD Helicopter maintenance documentation for instructions regarding parts of the aircraft that interface with these parts. 0.9 Abbreviations FAA Federal Aviation Administration FAR Federal Aviation Regulation ICA Instructions for Continued Airworthiness CMM Component Maintenance Manual Instructions for Continued Airworthiness 123-048-00 00-00-00 Page 2 Revision 0 11/14/18 0.12 Precautions The following definitions apply to safety labels used in this manual. Indicates a hazardous situation which, if not avoided, will result in death or serious injury. Indicates a hazardous situation which, if not avoided, could result in death or serious injury. Indicates a hazardous situation which, if not avoided, could result in minor or moderate injury. Draws the reader’s attention to important or unusual information not directly related to safety. Used to address practices not related to personal injury. 0.19 Distribution of Instructions for Continued Airworthiness Before performing maintenance ensure that the Instructions for Continued Airworthiness (ICA) in your possession is the most recent revision. Current revision levels of all manuals are posted on Onboard Systems Int'l web site at www.onboardsystems.com. Onboard Systems offers a free notification service via fax or e-mail for product alerts and documentation updates. By registering Onboard Systems products on the web site, we will be able to contact you if a service bulletin is issued, or if the documentation is updated. Notices can be chosen to be received on an immediate, weekly, or monthly schedule via fax, email or both methods. There is no charge for this service. Please visit the Onboard Systems web site at www.onboardsystems.com/notify.php to get started. Instructions for Continued Airworthiness 123-048-00 Revision 1 04-00-00 Page 1 12/11/18 Section 4 Airworthiness Limitations The Airworthiness Limitations section is FAA approved and specifies inspections and other maintenance required under Secs. 43.16 and 91.403 of the Federal Aviation Regulations unless an alternative program has been FAA approved. The following items of the Long Line Kit are life-limited. Captured metal parts (load rings, snap hooks, etc.) of the assemblies are also scrapped at retirement. Part Number Description Maximum Service Life** 490-014-00 Y-Rope 4 years 490-015-XX* Long Line 4 years 490-018-00 Lanyard 4 years *The XX represents length of the long line in feet divided by 10, e.g. - a 100 foot long line has a part number 490-015-10, a 150 foot long line has a part number 490-015-15, etc. ** Service life begins when the item is placed into service. This date must be marked by the operator in the reserved location on the component ID tag or using another method such as recording in a log book. FAA Approved: This page constitutes the Airworthiness Limitations Section in its entirety, is considered segregated from the rest of the document, and sets forth the FAA approved mandatory replacement times for the life-limited parts listed above. Instructions for Continued Airworthiness 123-048-00 04-00-00 Page 2 Revision 1 12/11/18 THIS PAGE INTENTIONALLY LEFT BLANK Instructions for Continued Airworthiness 123-048-00 Revision 2 05-00-00 Page 1 02/25/20 Section 5 Inspection and Overhaul Schedule The scheduled inspection intervals are maximums and are not to be exceeded. If the cargo hook system is subjected to unusual circumstances, extreme environmental conditions, etc., it is the responsibility of the operator to perform the inspections more frequently to ensure proper operation. There is no maintenance to be performed on the Load Weigh Indicator of the load weigh system (if installed). Do not open the enclosure, if repair is needed return it to the factory. 5.1 Annual/100 Hour Inspection Annually or 100 hours of external load operations, whichever comes first, inspect the cargo hook system per the following. Refer also to the cargo hook’s Component Maintenance Manual (manual no. 122-015-00) for additional inspection. Hours of external load operations should be interpreted to be (1) anything is attached to the cargo hook (whether or not a useful load is being transported) and (2) the aircraft is flying. If these conditions are NOT met, time does NOT need to be tracked. 1. Activate the helicopter’s electrical system and press the pushbutton switch for the primary cargo hook (the primary cargo hook switch is the original MDHI switch on the cyclic labeled “HOOK RELEASE”) to ensure the cargo hook electrical release system is operating correctly. The cargo hook must open. Reset the hook by hand after release. Repeat for the secondary cargo hook using the pushbutton switch integrated into the release lever installed on the cyclic labeled “SECONDARY HOOK RELEASE”. Depressing the cargo release button continuously in excess of 20 seconds will cause the cargo hook solenoid to overheat, possibly causing permanent damage. Instructions for Continued Airworthiness 123-048-00 05-00-00 Page 2 Revision 1 12/11/18 5.1 Annual/100 Hour Inspection continued 2. Check the function of the primary cargo hook’s hydraulic release system by pulling the inboard release lever on the cyclic. The lever should operate smoothly and the primary (forward) cargo hook must release. Return the load beam to its closed and locked position by hand after release. Verify that the hook lock indicator on the side of the hook returns to the fully locked position. In the fully locked position the hook lock indicator must align with the lines on the cover (see Figure 5.1.1). Repeat using the outboard lever on the cyclic for the secondary (aft) cargo hook. Figure 5.1.1 Hook Lock Indicator Hook Lock Indicator ACCEPTABLE Hook Lock Indicator 3. Move each cargo hook throughout its full range of motion and observe the hydraulic hose and electrical harnesses to ensure that they have enough slack. The hose or harness must not be the stops that prevent each cargo hook from moving freely in all directions. 4. Rotate pivoting joints at each cargo hook attachment to ensure that they rotate freely throughout their range of motion. 5. Visually inspect for presence and security of fasteners. 6. Visually inspect the external electrical harnesses and their connectors at the cargo hooks and at the fixed connectors on the belly for damage and security. 7. Visually inspect each external hydraulic hose and the connections to the cargo hooks and the fixed fittings on the belly for damage and security. 8. Visually inspect for cracks and damage in the Pillow Block and Pivot Link of the attach point assemblies. Refer to Table 5.2.2 for inspection criteria. Instructions for Continued Airworthiness 123-048-00 Revision 2 05-00-00 Page 3 02/25/20 5.1 Annual/100 Hour Inspection continued 9. Inspect for security of the Dual Master Cylinder on the cyclic. 10. Visually check for fluid leaks in the hydraulic release system. Any leakage of fluid is unacceptable. See troubleshooting section to determine the course of action. 11. Check the fluid level in the master cylinder on the cyclic. The master cylinder features a transparent lid through which the fluid level can be checked. Hydraulic fluid level must be within the “MIN-MAX” circle on the baffle plate (reference Figure 12.1.1). 12. Check one of the hydraulic release systems for air by pulling one of the levers firmly until it bottoms out. Check the push rod position (reference Figure 12.2.7). If some of the green ring on the push rod is visible, the system is adequately bled. If some of the green on the push rod is NOT visible with the lever completely pulled, the system has too much air in it and must be bled, see Section 12.2 for bleeding instructions. Repeat with the other lever to check the other cargo hook’s hydraulic release system. 13. Visually inspect the load weigh indicator (if optional load weigh system is installed) for damage and security. Instructions for Continued Airworthiness 123-048-00 05-00-00 Page 4 Revision 1 12/11/18 5.2 5 Year/1000 Hour Inspection Every 5 years or 1000 hours of external load operations, whichever comes first, remove the external load bearing components of the dual cargo hook system from the helicopter, disassemble, and inspect the parts per the following instructions. For numbers in ( ) refer to Figure 5.2.1. For parts not numbered in the primary cargo hook installation; these are the same P/N’s as used in the secondary cargo hook installation. Bushings do not need to be removed unless they are being replaced. 1. Disconnect the electrical release harness connectors and remove slave cylinder/plumbing assembly (see section 25.16 for removal instructions) from the cargo hooks. 2. Remove the cotter pin (18) from the nut (17) and remove nut and washers (15 and 16) from the end of the attach bolt (14). 3. Remove the attach bolt, separating it and the respective cargo hook from the secondary Pivot Link Assembly (9, 10, 11) or the primary Pivot Link Assembly (10, 11, 21). 4. Remove the four attach point bolts (7, 21) and washers (7) securing each pillow block (1, 20) to the hardpoints to remove the remaining components from the helicopter. 5. Separate the Pivot Link Assembly from the Pillow Block (1) by removing cotter pin (5), nut (4), washer (3), and bolt (2). Figure 5.2.1 Cargo Hook Installation Components/Disassembly Secondary Cargo Hook Installation Parts Primary Cargo Hook Installation Parts Instructions for Continued Airworthiness 123-048-00 Revision 3 05-00-00 Page 5 08/17/21 5.2 5 Year/1000 Hour Inspection continued Table 5.2.1 Cargo Hook Installation Parts Item Part No. Description Qty 1 292-019-00 Pillow Block 1 2 510-142-00 Bolt 2 3 510-109-00 Washer 2 4 510-108-00 Nut 2 5 510-222-00 Cotter Pin 2 6 220-047-00 Bumper 1 7 510-100-00 Washer 8 8 511-034-00 Bolt 4 9 292-020-00 Pivot Link 1 10 291-486-00 Flanged Bushing 4 11 290-364-00 Bushing 2 12 290-360-01 Bumper 1 13 232-803-00 Cargo Hook w/ Slave Cylinder 1 232-803-01 Cargo Hook w/ Slave Cylinder (for the 600N) 14** 290-332-00 Attach Bolt 2 15 510-183-00 Washer 4 16 510-174-00 Washer 2 17 510-170-00 Nut 2 18 510-178-00 Cotter Pin 2 19 232-456-00 Spacer Assembly 1 20 291-483-00 Pillow Block 1 21 510-308-00 Bolt 4 22 291-484-01* Pivot Link 1 23 232-809-00 Cargo Hook/Slave Cylinder 1 232-809-01 Cargo Hook/Slave Cylinder (for the 600N) *Supersedes P/N 291-484-00. **Replaced by Pin Load Cell (P/N 210-301-03 or P/N 210-226-03 for the 369/500 or P/N 210-301-05 for the 600N) at the primary cargo hook if load weigh system is installed. Washer (15) under Attach Bolt head is also not used with Pin Load Cell. 6. Carefully inspect detail parts in accordance with the instructions in Table 5.2.2. Inspect the parts in a clean, well-lighted room using standard dimensional measuring tools and visual methods. Repair parts found within inspection limits. Replace any part found beyond limits. 7. If the load weigh system is installed, return the Pin Load Cell Assembly to the factory for inspection and calibration. The factory will inspect the condition of the pin load cell and perform acceptance test procedures including calibration and zero balance, repairing as necessary. 8. In addition, remove the bleed screw (refer to Figure 12.2.4) at each cargo hook slave cylinder to drain the hydraulic release system***. Re-fill and bleed per the instructions in Section 12.2. ***Calendar time alone can be used for replacing hydraulic fluid. Instructions for Continued Airworthiness 123-048-00 05-00-00 Page 6 Revision 2 02/25/20 5.2 5 Year/1000 Hour Inspection continued Table 5.2.2 Dual Cargo Hook System Inspection Criteria Seq. Component Inspection Criteria and Limit Repair Action Finish 1. Pillow Block (1) Pivot Link (9) Pillow Block (20) Pivot Link (22) Nicks, dents, scratches, corrosion – 0.010 in. (0.254 mm) deep Blend at 10:1 ratio as required to provide smooth transitions. Glass bead blast at less than 30 PSI (2.11 KGF/CM2) to remove corrosion. Passivate per AMS-QQ-P-35 or ASTM A967. Any indication of cracks. None. N/A 2. Bolt (2) Wear on OD – 0.428 in. (10.87 mm) None. N/A 3. Flanged Bushing (10) Wear on ID – 0.450 in. (11.43 mm) None. N/A 4. Bushing (11) Wear on ID – 0.520 in. (13.21 mm) None. N/A 5. Attach Bolt (14) Wear on OD – 0.495 in. (12.57 mm) None. N/A 6. Spacer Assembly (19) Dents, nicks, cracks, gouges, scratches and corrosion – 0.020 in. (0.50 mm) deep Blend at 10:1 ratio as required to provide smooth transitions. Apply Alodine (MIL-DTL-5541) and zinc chromate primer (MIL-PRF- 23377 or similar) to affected surfaces. 7. Bumper (6) Denting, cuts or abrasions – 0.060 in. (1.27 mm) deep None. N/A 8. Bumper (12) Denting, cuts or abrasions – 0.060 in. (1.27 mm) deep None. N/A 9. Cargo Hook (13, 23) Refer to CMM 122-015-00 for inspection and overhaul instructions for the cargo hook. 10. Remaining bolts, nuts, washers, cotter pins. Wear, corrosion, or deterioration. None. N/A Instructions for Continued Airworthiness 123-048-00 Revision 1 05-00-00 Page 7 12/11/18 5.3 Long Line Kit Inspection Inspection of the long line kit includes a check before each use (not a maintenance activity) and an annual inspection. Refer also to the manufacturer’s Long Line User Manual. All of the manufacturer’s inspection requirements must be observed. The following figure shows the components of the long line kit P/N 200-449-XX. The Y-rope Assembly (item 24, 24.1) interfaces with the dual cargo hooks and is the only required component, for items connected below the Y-rope, locally approved alternate configurations may be used. If an alternate configuration is used refer to its maintenance documentation. Figure 5.3.1 Long Line Kit Components Instructions for Continued Airworthiness 123-048-00 05-00-00 Page 8 Revision 1 12/11/18 5.3 Long Line Kit Inspection continued Table 5.3.1 Long Line Kit Parts Item Part No. Description Qty 24 490-014-00 Y-rope Assembly 1 24.1 N/A** Load Ring 3 25 530-031-00 Carabiner 2 26 490-015-XX* Long Line 1 27 490-017-00 Weight Bag 1 28 292-017-00 Rigging Plate 1 29 490-018-00 Lanyard 1 29.1 N/A** Carabiner 1 29.2 N/A** Snap Hook 2 *Long Line P/N is completed by replacing the “XX” with the length divided by 10, for example a 100 foot long line is P/N 490-015-10 and a 150 foot long line is P/N 490-015-15, etc. **The Load Rings (24.1), Carabiner (29.1) and Snap Hooks (29.2) are integral to the Y-rope Assembly and Lanyard respectively. Instructions for Continued Airworthiness 123-048-00 Revision 1 05-00-00 Page 9 12/11/18 5.3 Long Line Kit Inspection continued Prior to a flight involving external load operations that includes use of the long line kit check the condition of the equipment and check the condition of the equipment after each use. Use the criteria defined in the annual inspection as a guide for the check. Also, consult the Long Line User’s Manual provided by the rope and manufacturer. Annually inspect the long line kit components per the following. Inspection of the Y-rope, Long Line Assembly, and Lanyard Assembly must be conducted by a qualified person. In addition to the instructions below, consult the Long Line User’s Manual provided by the rope manufacturer. Inspect the Y-rope Assembly (24) per the following. 1. Open the covers and inspect them on the inside and outside per the following. o Loose, cut or pulled zipper stitching. o Loose, cut or pulled stitching of cover to webbing. o Torn, cut or otherwise damaged cover material. o Legibility of “PRIMARY” and “SECONDARY” markings. o Condition and function of zipper. o Condition and function of hook and loop closure strap. 2. Inspect the internal webbing material of the Y-rope Assembly per the following. o Legibility and security of ID tag. o Acid or caustic burns. o Holes, tears, cuts or snags. o Broken or worn stitching in the load bearing splices. o Excessive abrasive wear. o Knots in any part of the sling. o Discoloration and brittle or stiff areas on any part of the sling. o Wear on Load Ring, inspect per criteria in Table 5.3.2. Instructions for Continued Airworthiness 123-048-00 05-00-00 Page 10 Revision 1 12/11/18 5.3 Long Line Kit Inspection continued Inspect the Long Line Assembly (26) per the following. Lay out the long line on a clean surface as it should be thoroughly inspected both visually and by feel over its entire length. 1. Unzip the cover and inspect it inside and outside per the following. o Loose, cut or pulled zipper stitching o Torn, cut or otherwise damaged loops (attaching each end of cover to thimbles). o Torn, cut or otherwise damaged cover material. o Condition and function of zipper. o Condition and function of hook and loop closure strap. 2. Inspect the rope and end terminations of the Long Line Assembly for the following. o Security of thimble, verify it is securely captured by the eye splice. o Condition of thimbles, inspect for signs of damage including corrosion, cracks, distortion, nicks, or rough surfaces. o Condition of the rope’s lockstitch thread and whipping thread at each eye splice, inspect for broken, cut or frayed threads. o Legibility and security of ID tag. Along the entire length of the rope, inspect for the following. o Externally observed abrasion, cut strands or areas of extensive fiber breakage. o Fiber breakage, fused or melted fibers observed internally (observed by prying or twisting to open the strands). Remove from service if an estimated 10% of fiber in any strand or the rope as a hole is damaged. o Uniform fiber breakage along the length of rope such that the entire rope appears covered with fuzz or whiskers. o Consistent diameter of the rope. Measure the rope dimeter in several locations and inspect for flat areas, bumps, or lumps. Remove from service if the diameter has been reduced by more than 10% in any area. o Discoloration, brittle fibers and hard or stiff areas that may indicate chemical, ultraviolet or heat damage. o Melted, hard or charred areas which may be evidence of excessive heat. Remove from service if areas in this condition affect more than 10% of the rope diameter or affect several adjacent strands along the length that affect more than 10% of strand diameters. o Cleanliness of the rope, stiffness of the rope may indicate dirt or grit embedded within its fibers. Instructions for Continued Airworthiness 123-048-00 Revision 1 05-00-00 Page 11 12/11/18 5.3 Long Line Kit Inspection continued Inspect the Lanyard Assembly (P/N 490-018-00) per the following. 1. Unzip the cover and inspect the inside and outside per the following. o Loose, cut or pulled zipper stitching o Loose, cut or pulled stitching of cover to webbing. o Torn, cut or otherwise damaged cover material. o Condition and function of zipper. o Condition and function of hook and loop closure strap. 2. Inspect the load carrying webbing material of the Lanyard Assembly for the following. o Legibility and security of ID tag. o Acid or caustic burns. o Holes, tears, cuts or snags. o Broken or worn stitching in the load bearing splices. o Excessive abrasive wear. o Knots in any part of the sling. o Discoloration and brittle or stiff areas on any part of the sling. 3. Inspect the captive carabiner and the two snap hooks of the Lanyard Assembly per Table 5.3.2. Instructions for Continued Airworthiness 123-048-00 05-00-00 Page 12 Revision 1 12/11/18 5.3 Long Line Kit Inspection continued Carefully inspect detail parts in accordance with the instructions in Table 5.3.2. Inspect the parts in a clean, well-lighted room using standard dimensional measuring tools and visual methods. Repair parts found within inspection limits. Replace any part found beyond limits. Table 5.3.2 Long Line Kit Inspection Criteria – Metallic Components Seq. Component Inspection Criteria and Limit Repair Action Finish 1. Load Ring (24.1, integral to Y-rope Assembly) Wear on inside of ring – minimum thickness of cross section of ring - 0.50 in. (12.7 mm) Blend at 10:1 ratio as required to provide smooth transitions. N/A 2. Carabiner (25) Nicks, dents, scratches, corrosion – 0.020 in. (0.127 mm) deep Blend at 10:1 ratio as required to provide smooth transitions. N/A Proper engagement of latching mechanism, 3-stage opening action should be free of any binding that may be an indication of deformation. None. N/A 3. Rigging Plate (28) Nicks, dents, scratches, corrosion – 0.020 in. (0.127 mm) deep Glass bead blast at less than 30 PSI (2.11 KGF/CM2) to remove corrosion. Passivate per AMS-QQ-P-35 or ASTM A967 Wear on inside diameter of holes for attachment to long line and loads. – See Figure 5.3.2 None. N/A 4. Carabiner (29.1, integral to Lanyard) Nicks, dents, scratches, corrosion – 0.020 in. (0.127 mm) deep Blend at 10:1 ratio as required to provide smooth transitions. N/A Proper engagement and operation of latching mechanism, 3-stage opening action should be free of any binding that may be an indication of deformation. None. N/A 5. Snap Hook (29.2, integral to Lanyard) Nicks, dents, scratches, corrosion – 0.020 in. (0.127 mm) deep Blend at 10:1 ratio as required to provide smooth transitions. N/A Proper engagement and operation of gate mechanism, 2-stage opening action should be free of any binding that may be an indication of deformation. None. N/A Instructions for Continued Airworthiness 123-048-00 Revision 1 05-00-00 Page 13 12/11/18 5.3 Long Line Kit Inspection continued Figure 5.3.2 Rigging Plate Inspection Criteria 0.47 in. (11.94 mm) minimum 4 places 0.62 in. (15.75 mm) minimum 2 places Instructions for Continued Airworthiness 123-048-00 05-00-00 Page 14 Revision 1 12/11/18 5.4 Cargo Hook Overhaul Schedule Time Between Overhaul (TBO): 1000 hours of external load operations or 5 years, whichever comes first. Hours of external load operations should be interpreted to be (1) anything is attached to the cargo hook (whether or not a useful load is being transported) and (2) the aircraft is flying. If these conditions are NOT met, time does NOT need to be tracked. Overhaul the cargo hooks per CMM 122-015-00. Contact Onboard Systems for guidance to locate authorized overhaul facilities. Instructions for Continued Airworthiness 123-048-00 Revision 3 11-00-00 Page 1 08/17/21 Section 11 Placards and Markings 11.1 Placards The Dual Cargo Hook System includes the following placards shown in Table 11.1. Table 11.1 Dual Cargo Hook System Placards Placard part number and appearance Location Placard P/N 215-379-00 (applicable to 369 series/500N) Installed on the belly of the helicopter, adjacent to the cargo hooks. Placard P/N 215-418-00 (applicable to 600N) Placard P/N 215-377-00 Installed on the release lever on the cyclic for the primary cargo hook. Placard P/N 215-377-00 Installed on the release lever on the cyclic for the secondary cargo hook. continued Instructions for Continued Airworthiness 123-048-00 11-00-00 Page 2 Revision 3 08/17/21 Table 11.1 Dual Cargo Hook System Placards continued Placard part number and appearance Location Placard P/N 215-377-00 Installed adjacent to the pushbutton switch integrated into the release lever on the cyclic for the secondary cargo hook. Placard P/N 215-381-00 Installed adjacent to the circuit breaker for the secondary cargo hook. Placard P/N 215-417-00 Installed adjacent to the circuit breaker for the load weigh system (if installed). Placard P/N 215-382-00 Located on the belly of the helicopter adjacent to the hydraulic hose connection for the primary cargo hook. Placard P/N 215-382-00 Located on the belly of the helicopter adjacent to the hydraulic hose connection for the secondary cargo hook. Instructions for Continued Airworthiness 123-048-00 Revision 0 12-00-00 Page 1 11/14/18 Section 12 Servicing 12.1 Maintenance of the Hydraulic Release System The system is filled with fluid at installation and does not consume fluid unless it leaks out. If any leakage is detected, the fluid level should be immediately checked. To check the fluid level: 1. Position the cyclic such that the reservoir is level. 2. The Dual Master Cylinder features a transparent lid through which the fluid level can be checked. Hydraulic fluid level must be within the MIN/MAX circle on the baffle surface (see Figure 12.1). 3. If necessary, remove lid and add hydraulic fluid as required (MIL-PRF-87257 hydraulic fluid is supplied with the system and is recommended, MIL-PRF-5606 fluid is also compatible). When re-installing lid do not over-tighten screws. Figure 12.1.1 Checking Hydraulic Fluid Level Min/Max Circle If leakage is noted around any plumbing fittings, the fittings may be tightened until the leakage quits. If leakage is noted around the pistons in either the master or slave cylinders the leaking cylinder must be repaired. See the instructions for repair in this section. Instructions for Continued Airworthiness 123-048-00 12-00-00 Page 2 Revision 0 11/14/18 12.1 Maintenance of the Hydraulic Release System, continued Master Cylinder Repair If fluid is leaking around the piston, the only repair is to remove and replace the cup seal and O-ring. The master cylinder must be disassembled, inspected and then re- assembled with new seals. Disassembly: 1. Remove snap ring. Use caution when removing snap ring since the piston is spring loaded against the washer and snap ring. The piston will pop out of the housing when the snap ring is removed. Use the lever to put pressure on the piston while removing snap ring. 2. Loosen the set screw and disconnect barrel nut on lever. See Figure 12.1.2. 3. Remove the piston and spring. See Figure 12.1.3 for parts breakdown. 4. Inspect the master cylinder bore for scratches. If any scratches or gouges are visible in the bore, the master cylinder must be replaced. Re-assembly 1. If the bore condition is acceptable, replace the cup seal and O-ring on the piston assembly. Orient the cup seal as shown in Figure 12.1.4. Stretch seals over piston into grooves. 2. Lubricate the piston seals and cylinder bore generously with hydraulic fluid. 3. Place the spring in the cylinder bore. 4. Pass the push rod through the washer. 5. Thread the push rod into the barrel nut until approximately 1/16” of thread is visible through the opposite side of the barrel nut. 6. Insert the small spring into the piston assembly and insert the piston assembly into the master cylinder bore using a firm rocking motion. 7. Use the lever to compress the spring and hold the piston in place. 8. Use snap ring pliers to install the snap ring. 9. Secure push rod threads by tightening set screw. Figure 12.1.2 Master Cylinder Lever Disconnect push rod washer set screw barrel nut Turn until barrel nut is disconnected from push rod. snap ring Instructions for Continued Airworthiness 123-048-00 Revision 0 12-00-00 Page 3 11/14/18 12.1 Maintenance of the Hydraulic Release System, continued Master Cylinder Repair continued Figure 12.1.3 Master Cylinder Piston Removal washer spring piston assembly spring push rod snap ring Only one piston removal shown, levers and shaft not shown Figure 12.1.4 Master Cylinder Piston Seal Orientation Cup Seal (P/N 556-048-00) Note seal orientation. O-ring (P/N 556-047-00) Piston (P/N 290-814-01) Slave Cylinder Repair If the slave cylinder is leaking fluid around the piston rod, the only repair possible is to remove and replace the quad ring. Disassembly: 1. Remove cap, piston, and seal (see Figure 12.1.5). 2. Inspect bore of slave cylinder for scratches or gouges. If any are present the assembly must be replaced. 3. Remove bushing in cap by pressing it out. 4. Remove quad ring by stretching it over the piston. Re-assembly: 1. Press new bushing into cap. 2. Stretch new quad ring over piston into groove. 3. Clean and lubricate cylinder bore and piston seal with hydraulic fluid. 4. Insert piston into cylinder taking care not to damage edges of quad ring. 5. Screw on cap and torque to 50-60 in-lbs. Instructions for Continued Airworthiness 123-048-00 12-00-00 Page 4 Revision 0 11/14/18 12.1 Maintenance of the Hydraulic Release System, continued Slave Cylinder Repair continued Figure 12.1.5 Slave Cylinder Piston Removal Piston (P/N 290-805-00) Quad Ring (P/N 556-097-00) Cylinder Cap (P/N 290-802-00) Bushing (P/N 517-040-00) Instructions for Continued Airworthiness 123-048-00 Revision 0 12-00-00 Page 5 11/14/18 12.2 Bleeding Hydraulic System Filling and bleeding requires two persons, one to inject hydraulic fluid through the system and the other to observe the reservoir. Following is the procedure. Bleeding procedure: 1. Obtain the hydraulic hook bleed kit, 212-014-02. This kit consists of 2 ounces of MIL-PRF-87257 fluid, a syringe, a female barb fitting, a length of PVC tubing, and a bleed adapter fitting. The bleed kit is included in new hook kits. Assemble the bleed kit by press fitting each component as shown. Figure 12.2.1 Hydraulic Hook Bleed Kit Bleed Adapter PVC Tubing Female X Barb Fitting Syringe 2. Place an absorbent towel under the master cylinder. Use best shop practices to keep foreign material out of the hydraulic system. FOD will plug orifices, damage seals and/or scratch sealing surfaces necessitating system rebuild. Use only clean hydraulic fluid from sealed containers. Instructions for Continued Airworthiness 123-048-00 12-00-00 Page 6 Revision 0 11/14/18 12.2 Bleeding Hydraulic System, continued 3. Connect each slave cylinder assembly plumbing to the respective master cylinder assembly plumbing if not already done. 4. Remove screws, reservoir lid, and baffle from the master cylinder reservoir as shown in Figure 12.2.3. Figure 12.2.3 Reservoir Disassembly Screw (4) Reservoir Lid Baffle Plate Instructions for Continued Airworthiness 123-048-00 Revision 0 12-00-00 Page 7 11/14/18 12.2 Bleeding Hydraulic System, continued 5. Remove the screw, two washers, and thread seal washer from either cargo hook slave cylinder, see Figure 12.2.4. Figure 12.2.4 Screw and Washer Removal Screw Washers Thread Seal Washer 6. Fill the syringe with approximately 35 cc of hydraulic fluid and purge any remaining air in the syringe and tubing. Screw the end of the bleed adapter into the screw hole on the slave cylinder to create a tight seal. See Figure 12.2.5. 7. While observing the reservoir, slowly push on the syringe plunger to force fluid through the slave cylinder, hydraulic hose, and up to the master cylinder reservoir. There will be some resistance during filling—this is normal. Injecting the fluid into the system too rapidly may cause the fluid to spray up and out of the master cylinder reservoir. Wear safety glasses when observing fluid reservoir while filling. Figure 12.2.5 Injecting Hydraulic Fluid Bleed Adapter PVC tubing Female X Barb Fitting Syringe Instructions for Continued Airworthiness 123-048-00 12-00-00 Page 8 Revision 0 11/14/18 12.2 Bleeding Hydraulic System, continued 8. Continue to force fluid into the master cylinder reservoir until the reservoir is about to the top of the divider. If bleeding an already filled system, you may need to draw fluid from the master cylinder reservoir during this step to prevent overflow. 9. Have the washers, thread seal washer, and screw ready to install as fluid will drain from the screw hole when the bleed adapter is removed. 10. Remove the bleed adapter from the screw hole and promptly re-install the washers, thread seal washer, and screw, see Figure 12.2.4. 11. Allow the system to rest for several minutes. This will allow any air to rise through the system. 12. Very slowly pull the release lever on the master cylinder and watch for bubbles. If bubbles are observed rising within the reservoir, continue to slowly cycle the lever until there are no more. Actuating the lever releases air trapped within the master cylinder. Pull the lever very slowly! When the reservoir is not baffled and capped, a hard pull will cause fluid to erupt over the edge of the reservoir. 13. Repeat steps 5 – 12 for the other cargo hook. Instructions for Continued Airworthiness 123-048-00 Revision 0 12-00-00 Page 9 11/14/18 12.2 Bleeding Hydraulic System, continued 14. Check the system for air by actuating the lever firmly until it bottoms out. Check the push rod position (see Figure 12.2.7). If some of the green ring on the push rod is visible, proceed to step 13. If some of the green on the push rod is not visible with the lever completely pulled, the system has too much air in it and needs further bleeding. To do this, repeat steps 5 – 12. 15. After the system is properly bled, verify that the reservoir is approximately half full of hydraulic fluid. Fluid should be visible above the baffle. 16. Re-install the baffle plate and the reservoir lid. 17. Check the system for proper operation. Fully actuate the secondary release lever (left lever), the secondary (aft) cargo hook must open and the lever must have a firm feel. Fully actuate the primary release lever (on the right), the primary (forward) cargo hook must open and the lever must have a firm feel. 18. Disassemble and thoroughly clean the bleed kit with isopropyl alcohol. Allow it to dry. Not cleaning the syringe will render it unusable. Reassemble and store for next use. Figure 12.2.7 Checking System for Air Some of the green stripe must remain visible when the release lever is fully actuated. Push Rod Instructions for Continued Airworthiness 123-048-00 12-00-00 Page 10 Revision 0 11/14/18 12.3 Lubrication Information Lubrication of Cargo Hook and linkage pivot points is recommended every 500 hours of external load operations. Lubricate the pivot points illustrated in Figure 12.3.1. Recommended lubricants are AeroShell 7 (MIL-PRF-23827) or Mobilgrease 28 (MIL-PRF-81322). For re-assembly after lubrication, tighten nuts to finger tight until fully seated then rotate to previous castellation if necessary to install cotter pin. Do not tighten nut on pin load cell (if installed) more than finger tight. Over-tightening will damage load cell. Figure 12.3.1 Lubrication Points (primary cargo hook shown) Apply grease. Apply grease.