Attach02_PDM_Work_Spec.pdf

TH‐1H DEPOT LEVEL MAINTENANCE

PROGRAMMED DEPOT MAINTENANCE (PDM)

WORK SPECIFICATION

DOCUMENT NUMBER: TH‐1H‐13‐070‐001

Original: 18 July 2013

Revision 1: 24 Feb 2014 Revision 2: 14 May 2014 Revision 3: 9 Aug 2016 Revision 4: 3 Oct 2017

Approved by:

JERRY P. BYRD

AFLCMC/WIU (SOF/PR) Rotary Wing Chief Engineer

PREPARED BY: USAF H-1 SYSTEM PROGRAM OFFICE, AFLCMC/WIUED

SUMMARY OF CHANGES

Changes made in most recent revision are indicated throughout this document using bold text.

Revision 4

• Global clarification/changes between “DLM” (which includes UDLM) and “PDM” (which consists of required work every 8 years).

• Para 3.2.4.10. Updated to remove additional flight controls.

• Para 3.2.4.10.1 added.

• Para 3.2.4.11. Updated to remove additional heating ducting.

• Para 3.2.7.4. Clarified fuel cell preservation requirements per manufacturer recommendation.

• Para 3.3.1.2 added.

• Para 3.3.2.d. Added required removal and replacement of seals attached with adhesive.

• Para 3.3.2.n. Added required removal and replacement of select air distribution system components.

• Para 3.3.4, Structure. Added NDI requirement of main beam tee caps just forward of pylon (increased scrutiny due to past cracks found during PDM). Added 100% replacement of forward cargo door tracks.

• Para 3.3.4, Crew Doors. Added 100% replacement of hinge springs.

• Para 3.3.4, Landing Gear. Changed “Bell WI” to “approved work instruction”. Added 100% replacement of crosstube support fittings and structural support angles.

• Para 3.3.4, Flight Controls. Added mandatory cyclic/collective stick boot replacement.

• Para 3.3.4, Air Distribution System. Added mandatory duct replacements.

• Para 3.3.5, Structure. Added 100% replacement of aft cargo door tracks and tailboom attachment bulkhead.

• Para 3.3.5, Cargo Doors. Added 100% replacement of rollers and slide.

• Para 3.3.6, Transmission Damper Supports. Added 100% replacement of transmission mount boots.

• Para 3.3.7, Engine Mount Assemblies. Added part numbers and 100% replacement of bearings on aft engine mounts. Rod end bearing tolerance limits changed.

• Para 3.3.8, Structure. Clarify tailboom attachment bolts to be replaced.

• Para 3.3.9. Added paragraph for maintenance to removed components.

• Para 3.4.1.1. Various changes and clarifications.

• Para 3.4.1.2. Various changes and clarifications.

• Para 3.4.3.1. Structural, Metal, and Airframe Repairs. Deleted T.O. 1H-1(T)H-2-1-1.

• Para 3.4.3.9. Added a statement to replace worn/dry rotted/deteriorated rubber seals/gaskets/grommets.

• Para 3.4.3.11. Added a statement to populate connectors with missing filler pins. Added a statement to string tie wires with zip tie or missing string tie.

• Para 3.4.5.5. Referenced paint drawing that calls out Cor-Ban stencil.

• Para 3.4.6. Added statement to clarify primary focus areas of water tightness test are nose avionics bay and upper circuit breaker panel.

• Para 4. Moved CSI list to Appendix E.

• Appendix C added.

• Appendix D added.

• Appendix E added (CSI list moved from paragraph 4).

Revision 3

• General grammar and formatting changes.

• Para 2.1. Added word “main” in line 1.

• Para 3.1.1.5. Corrected name of Vibration Office. Update Vibration Office email address.

• Para 3.2.1. Joint Oil Analysis Program (JOAP). Added language regarding hydraulic sampling.

• Para 3.2.4.3 Powerplant Removal. Added “exterior” to line 7, clarifying that only exterior requires cleaning. Added sentence stating that compressor wash need not be accomplished upon induction.

Added statement referencing paragraph 3.4.1.2 that allows some O/I-level engine maintenance when approved by CFA/CFR.

• Para 3.2.7. Aircraft, Avionics and Component Preservation. Changed “T.O. 2J-1-18” to “T.O. 2J- T53-12” in line 7.

• Para 3.2.7.3 Engine Preservation. Changed “T.O. 2J-1-18” to “T.O. 2J-T53-12, paragraph 5.G” in line 6 through 7.

• Para 3.3.2.y. Combined redundant sentences (no content change).

• Para 3.3.3, Honeycomb Panels. Added list of honeycomb panels (formalizing what is already accomplished).

• Para 3.3.4, Honeycomb Panels. Added Fuselage Stations, Butt Lines, and clarifying identification terms to Items 1, 3, and 4. Corrected Fuselage Stations and P/N for Center Fuel Cell Lower Panel.

Added Items 8 through 11 (formalizing what is already accomplished).

• Para 3.3.4, Structure. Added clarifying terms for main beam caps.

• Para 3.3.4, Crew Doors. Clarified requirement to include both door and airframe seals.

• Para 3.3.4, Landing Gear Assembly. Information in Ft. Rucker Maintenance Process Control

Document Number 5769 has been incorporated into T.O. 1H-1(T)H-2-1, paragraph 3.2.4.1. Added 100% replacement of short saddles. Added T.O. 1H-1(U)N-3-1 to inspection requirements.

Combined redundant inspection steps.

• Para 3.3.5, Honeycomb Panels. Added clarifying identification terms to Items 3 through 9 and main beam caps. Added precise aircraft location to main beam caps. Changed P/N for Items 8 and 9 from Installation to Assembly P/N’s. Added Items 10 through 27 (formalizing what is already accomplished).

• Para 3.3.5, Honeycomb Cabin Floor Panels. Added this section to define floor panels to inspect (formalizing what is already accomplished).

• Para 3.3.5, Cargo Doors. Clarified requirement to include both door and airframe seals.

• Para 3.3.7, Honeycomb Panels. Added clarifying identification term and precise aircraft location to main beam caps. Corrected P/N for Items 4 and 5 to reflect upper panel assembly. Added alternate P/N for Item 7. Corrected P/N for Item 8. Bell-Ozark stated that -183 Center Deck is the proper P/N and is produced from a modified 205-031-197-139/-127/-053 deck. Deleted Item 1 (Fwd Firewall), as it is titanium not honeycomb.

• Para 3.3.8, Structures. Re-wrote first item (tailboom attach fitting) inspection to include Bell Information Letter TH-1H-13-01 criteria. Added 50 hour tailboom inspection IAW T.O. 1H-1(T)H- 6 (formalizing what is already accomplished).

• Para 3.4.1.1. Clarification of Required Depot-Level Maintenance Tasks.

• Para 3.4.1.2. Clarification of Authorized Organizational/Intermediate-Level Maintenance Tasks.

• Para 3.4.1.3. Identified/formalized two specific examples of calendar and scheduled inspections that are already performed in the context of DLM process.

• Para 3.4.1.4. Authorized Depot-Level Maintenance Tasks. Paragraph added for clarification of requirements.

• Para 3.4.4.2.2. Interior Painting. Added T.O. 1H-1(U)N-3-1 to list of required documents.

• Para 3.4.4.2.3. Special Markings. Added T.O. 1H-1(U)N-3-1 as document governing interior stencils and markings.

• Para 3.5.7.3. Cleaning the Aircraft. Added “interior and exterior” to line 2 and clarified the requirement for performing compressor wash prior to topping check.

• Para 3.5.7.6. Aircraft Fueling. Change fueling reference from “operator’s” to “maintenance” manual.

Added language regarding fuel sampling (matching what is currently accomplished).

• Para 3.5.7.7. Rewrote hydraulic sampling procedure to mirror actions currently performed.

• Para 3.5.10. Complete Weight and Balance. Updated email address for 23 FTS QA.

• Para 3.5.16. Rewrote based on recommended changes from Mike Thomas, Vibration Program Management Office. Added CFA/CFR authorized use of RADS for rotor track/balance if VXP does not achieve solution within T.O. limits after four flights.

• Para 4. Critical Safety Item section rewritten. One P/N added to CSI list: 205-076-099-001.

• Appendix B added. BHT Information Letter TH-1H-13-01 with inspection criteria for tailboom attachment fittings.

1. SCOPE

1.1. Scope: This work specification establishes the standard Depot Level Maintenance (DLM) requirements during Programmed Depot Maintenance (PDM) for the TH-1H model aircraft. The U.S. Air Force TH-1H training helicopter, manufactured by Lockheed Martin, is a highly modified version of the U.S. Army UH- 1H/V utility helicopter. The modifications, detailed in Time Compliance Technical Order (TCTO) 1H-1(T)H- 501, include the Bell Helicopter UH-1H-II (Huey II) kit (ref 205-705-001-101K, Kit Assembly Inspection Log or “KAIL”), the Honeywell T53-L-703 commercial engine upgrade, and the Bell 212 nose installation; a communications and navigation systems avionics upgrade; an electronic MFD glass cockpit; an emergency locator transmitter; and crashworthy pilot, copilot and center observer seat installations.

1.2. Purpose: The primary purpose of the DLM program for the TH-1H aircraft is to accomplish PDM, aircraft structural inspections and repairs concurrent with zonal inspections and repairs at a depth and skill level greater than that available at organizational and intermediate (O&I) maintenance levels. The zonal inspections will address electrical wiring, hydraulic system components, fuel system components, and general integrity of the remaining items in that zone. Components (including engine, drivetrain elements, avionics, etc.) are removed to the extent required, and as specified in this work specification, to conduct a detailed airframe inspection and will normally not be the subject of any depot-level maintenance effort. The DLM program will also consist of drop-in maintenance and the deployment of Contractor Field Teams (CFT), as required. Any Unprogrammed Depot Level Maintenance (UDLM) requirements, such as drop-in maintenance or CFT, shall be defined in a separate Statement of Work (SOW) and estimated, negotiated, approved, and charged as Over and Above (O&A) work IAW contract procedures.

1.3. Schedule: Starting in FY 2010, the depot level maintenance concept for the USAF TH-1H was established with an initial 8 year fixed interval PDM cycle. Under this concept, a fixed DLM inspection interval was established and incorporated (reference T.O. 00-25-4).

2. DOCUMENT CONTENTS

2.1. This TH-1H PDM Work Specification consists of six main sections (see PWS Figure 1, Typical PDM Process Flow), and is organized to reflect the PDM process. Each section addresses general policies and guidance for the PDM process.

2.1.1. Preparation for Induction: Section 3.1 of this PDM Work Specification describes tasks required by the contractor upon arrival of the aircraft at the contractor’s facility.

2.1.2. Aircraft Induction: Section 3.2 of this PDM Work Specification describes tasks required to prepare the aircraft for inspection and maintenance.

2.1.3. Inspection/Repair Authorization: Section 3.3 of this PDM Work Specification outlines inspection tasks required to locate and identify defects, including corrosion. Work outside of the Firm Fixed Price (FFP) tasks, shall be estimated, negotiated, approved, and charged IAW the contract O&A procedures.

2.1.4. Maintenance and Repair: Section 3.4 of this PDM Work Specification sets guidelines for and outlines repair tasks required to correct deficiencies discovered during the inspection process, and describes general maintenance tasks to be accomplished during the DLM process.

2.1.5. Preparation for Delivery: Section 3.5 of this PDM Work Specification describes tasks required to prepare the aircraft for delivery.

2.1.6. Aircraft Delivery: Section 3.6 of this PDM Work Specification details responsibilities of the rework facility during the process of delivering the reworked aircraft to the gaining custodian.

3. PDM PROCESS FLOW

3.1. PREPARATION FOR INDUCTION:

3.1.1. Receipt of aircraft at facility:

3.1.1.1. Tasks and Requirements upon Aircraft Arrival at the Contractor’s Facility - This section details the contractor’s responsibilities, tasks and requirements to be accomplished upon the aircraft arrival at the contractor’s facility. Some activities include coordination and participation of the owning activity.

3.1.1.2. Aircraft Inventory Record - After arrival of the aircraft at the contractor’s facility, the contractor shall perform a complete and thorough aircraft inventory jointly with the owning activity. The inventory is to be conducted as soon as possible after receiving the aircraft. The owning activity and contractor shall complete a joint aircraft inventory of those items and components listed on DD Form 365-1, Chart A, of the aircraft logs and records. When a joint inventory is not possible, the CFR shall perform the joint inventory with the contractor.

3.1.1.3. Review of Aircraft Discrepancies - After aircraft arrival, the contractor shall review discrepancies discovered by the aircrew during the aircraft ferry flight. Those discrepancies shall be recorded on AFTO Form 781A as required.

3.1.1.4. Logs and Records Review - The aircraft shall arrive at the contractor’s facility with accurate and up-to-date logbooks and records. After arrival of the aircraft at the contractor’s facility a review of the aircraft logs and records shall be performed jointly by the depot and owning activity. Discrepancies discovered with any logbooks or records shall be corrected by the contractor with the assistance of the aircraft owing unit. The review, at a minimum, shall include aircraft logbooks, engine logbooks, historical files, and component history records. In addition, discrepancy files; main and tail rotor balance charts; vibration analysis signature cards;

and functional check flight record cards, as available, shall be reviewed for discrepancies that shall be corrected during the repair process. A review of the logs and records shall include the following:

• Aircraft logbooks and records

• Engine logbooks and records

• Historical files and records

• Discrepancies discovered during the incoming ferry flight

• Outstanding AFTO Form 781 open write-ups

• Main and tail rotor balance charts

• Vibration signature cards

• Functional check flight record cards

• Weight and Balance records

3.1.1.5. Review Vibration Analysis Cards - The aircraft owning activity will perform/collect vibration signature data using the VXP Balancer/Analyzer and VXP Application File PN: 15727-03 or current equivalent equipment in use with aircraft Configuration File provided by the AETC Vibration Program Management Office (VPMO) in accordance with T.O. 1H-1(T)H-2-1, Para 5.21.3. Following completion of data collection the owning activity will send all vibration log files collected for the aircraft via email to:

58MXG.C-130vibrationprogram@us.af.mil. The VPMO will analyze the vibration signature log files and provide the contractor and owning activity a written report listing vibration levels of dynamic components with recommendation to the contractor of any indications of discrepancies or suspect areas that will require further investigation or correction during the PDM process. The contractor will review these records after arrival of the aircraft and perform maintenance as required during the PDM process (See Section 3.4 of this

PDM Work Specification).

3.1.1.6. Disarm and Remove Explosives and Ordnance - All explosives and ordnance shall be disarmed and/or removed from the aircraft prior to induction to the contractor’s facility IAW the applicable aircraft maintenance manual.

3.1.1.7. Perform Check Flight - Prior to aircraft induction the contractor shall perform a joint check flight with a representative of the owning activity for all flyable aircraft. The check flight may be accomplished concurrently with the aircraft ferry flight to the DLM facility, with the DLM facility test pilot serving as aircraft co-pilot. A check flight consists of a thorough inspection and airworthiness check of the aircraft before flight, during flight, and upon completion of the check flight. On flyable aircraft, all systems and components shall be assumed operational unless a discrepancy is noted. It shall be the responsibility of the contractor to ensure all discrepancies are recorded properly. The aircraft shall be repaired and returned to the gaining custodian with the same systems operating as when the aircraft was inducted unless otherwise directed by the Cognizant Field Authority/Cognizant Field Representative (CFA/CFR).

3.2. AIRCRAFT INDUCTION: This section details the depot facility responsibilities and tasks required to prepare the inducted aircraft for inspection and repair.

3.2.1. Joint Oil Analysis Program (JOAP): Oil analysis shall be performed on engine, transmission, 42° gearbox, and 90° gearbox IAW the applicable aircraft maintenance manual by the depot facility prior to inspection and repair. Upon receipt of the aircraft, sample the hydraulic fluid from hydraulic reservoir while the system is warm. Submit sample for JOAP analysis and provide the report to CFA (AFLCMC/WIUED SPO Engineering) for disposition.

3.2.2. Purging the Aircraft of All Fluids, Fuels, Oils, and Hydraulic Fluids: The aircraft shall be purged of all fuels, oils, and fluids prior to inspection and repair.

3.2.3. Strip Paint: All aircraft undergoing the scheduled PDM repair process shall be stripped of paint and finishes on exterior airframe surfaces (Fuselage, Tailboom & Landing Gear). Exempt fiberglass surfaces from strip and paint. Contractor’s processes for stripping paint are acceptable with prior approval by

CFR/CFA.

3.2.4. Removal of Aircraft Components: Aircraft components are to be removed to facilitate individual inspections and repairs. Noted removal of components is mandatory unless otherwise specified by an “(as required)” annotation beside the component. Unless specified otherwise, component evaluation after removal shall be limited to a visual inspection for general condition and obvious defects only. Any damage discovered that requires repair must meet the defect correction repair criteria specified in paragraph 3.4.1 in order for the damage to be qualified as depot level repair.

3.2.4.1. Removal of Airframe Components: The following items shall be removed to perform inspection actions. Upon removal, they shall be evaluated, and, if serviceable, retained for reinstallation in or on the aircraft. Refer to applicable aircraft maintenance manuals and drawings for removal procedures.

• Cockpit floor, both removable and fixed panels

• Cabin floors, both removable and fixed panels

• Sound proofing, flooring, and loose equipment from the fuselage interior as required to accomplish inspection requirements

• Tailboom assembly

3.2.4.2. Removal of Landing Gear System Components: The following items shall be removed to perform inspection actions. Upon removal, they shall be evaluated and, if serviceable, retained for reinstallation in or on the aircraft. Refer to applicable aircraft maintenance manuals for removal procedures.

• Main Landing Gear Assembly

3.2.4.3. Removal of Powerplant System Components: The following items shall be removed to perform inspection actions. Aircraft inducted to the depot facility under the PDM concept shall have a fully operational engine. The repair activity shall not repair or overhaul the aircraft engine, except as required to complete PDM per paragraph 3.4.1.2. No disassembly of the engine is authorized without prior CFA/CFR approval. No removal of engine components is authorized without CFA/CFR approval. All components removed from an engine to facilitate storage shall be tagged, and shall have an inventory link with that engine.

Engine components shall not be interchanged without CFA/CFR approval. Engine exterior shall be cleaned IAW T.O. 1H-1(T)H-2-1 prior to removal from the aircraft. Engine compressor wash need not be accomplished at this time. Upon removal, the engine shall be visually inspected, preserved, and stored as a Quick Engine Change (QEC) assembly during the repair process. Refer to applicable aircraft maintenance manuals for removal procedures. The contractor shall preserve the engine in accordance with paragraph 3.2.7.3.

• Engine

3.2.4.4. Removal of Rotor System Components: The following items shall be removed to perform inspection actions. Upon removal, they shall be evaluated, and, if serviceable, retained for reinstallation in or

• Main Rotor Mast Assembly

• Main Rotor Hub

• Swashplate Assembly

• Main Rotor Blades

• Stabilizer Bar Assembly

• Scissors and Sleeve Assembly

• Stabilizer Bar Dampers

• Tail Rotor Hub

• Tail Rotor Blades

• Tail Rotor Crosshead Assembly

3.2.4.5. Removal of Drive System Components: The following items shall be removed to perform inspection actions. Upon removal, they shall be evaluated, and, if serviceable, retained for reinstallation in or

• Main Transmission Assembly

• Main Drive Shaft

• 42° Gear Box

• Tail Rotor Drive Shafts

• 90° Gear Box

• Hanger Bearings

3.2.4.6. Removal of Hydraulic Systems Components: The following items are to be removed as required to perform zonal inspection actions. Upon removal, they shall be evaluated, and, if serviceable, retained for reinstallation in or on the aircraft. Refer to applicable aircraft maintenance manuals for removal procedures.

• Hydraulic Pump (as required)

NOTE

Hydraulic lines, valves, and disconnects should remain installed during the PDM process. Remove lines, valves, or disconnects only to facilitate extended inspection and repair. Ensure all disturbed lines and components are capped to prevent system contamination. Remove/replace flexible hoses as noted in paragraph 3.3.2.m.

3.2.4.7. Removal of Instrument Systems Components: The following items are to be removed to perform zonal inspection actions. Upon removal, they shall be evaluated, and, if serviceable, retained for reinstallation in or on the aircraft. Refer to applicable aircraft maintenance manuals for removal procedures.

All LRU’s/mounts shall be removed from the nose shelves for evaluation of the component and the shelves.

• Flight Instruments (as required)

• Engine Instruments (as required)

• Caution/Advisory Panel (as required)

• Antennas

• LRU’s/Mounts

• Multi-Function Displays (MFD’s)

• Standby Instruments (as required)

• Engine Data Concentrator Units (EDCU’s)

• Air Data Computers

3.2.4.8. Removal of Electrical System Components: The following items are to be removed to perform zonal inspection actions. Upon removal, they shall be evaluated, and, if serviceable, retained for reinstallation in or

• Voltage Regulators

• Circuit Breaker Panels (as required)

• Relay Panels (as required)

• Inverter

• Main and Standby Generators

• Aircraft Battery

• Aircraft Interior/Exterior Lighting (as required)

Electrical wires, harnesses, and connectors should remain installed during the PDM process. Remove electrical wires, harnesses, or connectors only to facilitate extended inspection and repair.

3.2.4.9. Removal of Fuel System Components: The following items shall be removed to perform inspection actions. Upon removal, they shall be evaluated, and, if serviceable, retained for reinstallation. Refer to applicable aircraft maintenance manuals for removal procedures.

• Fuel Cells

Fuel system lines, valves, and disconnects should remain installed during the PDM process. Remove lines, valves, or disconnects only to facilitate extended inspection, repair, and paint touch up.

3.2.4.10. Removal of Flight Control Systems Components: Remove flight control systems components to perform zonal inspection actions. Upon removal, they shall be evaluated, and, if serviceable, retained for reinstallation in or on the aircraft. Refer to applicable aircraft maintenance manuals for removal procedures.

Removals shall include:

• Flight Control Rods, with exceptions listed in paragraph 3.2.4.10.1

• Cyclic and Collective Servos

◦ Disconnect upper clevis (P/N 204-076-268-101) and upper tube (P/N 204-076-267-1/- 3/-5) from rest of each servo.

• Tail Rotor Servo (P/N 204-076-053-011) and Mount (P/N 205-001-701-001)

• L/H and R/H Pedal Adjuster Assemblies (P/N 204-001-762-013/-015)

• Mixing Lever Assy (P/N 205-001-301-001)

• Lever/Bellcrank (P/N 205-001-704-001)

3.2.4.10.1. The following flight control systems components shall remain installed:

• Flight Control Rods:

◦ P/N 204-001-027-005 (Cyclic)

◦ P/N 205-001-014-001 (Cyclic)

◦ P/N 204-001-027-023 (Collective)

◦ P/N 205-001-011-017 (Collective)

◦ P/N 204-001-012-001 (Anti-Torque). Disconnect from pedal adjuster bellcranks, at a minimum.

◦ P/N 205-001-011-009 (Anti-Torque)

• Cyclic Lateral Interconnect Support (P/N 204-001-514-001)

• Pilot/Copilot Anti-Torque Pedals

• Collective Bellcrank Support (P/N 205-030-725-013)

3.2.4.11. Removal of Environmental System Components: The following items are to be removed, as required for access, to perform inspection actions. Upon removal, they shall be evaluated, and, if serviceable, retained for reinstallation in or on the aircraft. Refer to applicable aircraft maintenance manuals for removal procedures.

• Heating and Ventilation Ducting, including everything downstream of bleed air tee (P/N

AN783D16) at STA 211 bulkhead.

3.2.4.12. Removal of Emergency Equipment: The following items shall be removed to perform inspection actions. Upon removal, they shall be evaluated, and, if serviceable, retained for reinstallation in or on the aircraft. Refer to applicable aircraft maintenance manuals for removal procedures.

• First Aid Kits

• Cabin Fire Extinguishers

• Emergency Locator Transmitter (ELT)

3.2.4.13. Removal of Center Pedestal Equipment: Equipment mounted in the center pedestal shall be removed to perform inspection actions. Upon removal, they shall be evaluated and, if serviceable, retained for reinstallation. Refer to the applicable aircraft maintenance manuals for removal procedures.

3.2.4.14. Removal of Utility System Components: The following items shall be removed to perform inspection actions. Upon removal, they shall be evaluated, and, if serviceable, retained for reinstallation, with the exception of 100% replacement of wiper blades, in or on the aircraft. Refer to applicable aircraft maintenance manuals for removal procedures.

• Windshield Wipers

• Windshield Wiper Motors (as required)

3.2.4.15. Removal of Miscellaneous Components: The following items shall be removed to perform inspection actions. Upon removal, they shall be evaluated, and, if serviceable, retained for reinstallation in or

• Oil Cooler Assembly

3.2.5. Visual Inspection and Disposition of Removed Components: The following paragraphs provide guidance to the depot facility for the visual inspection and subsequent disposition of avionics and other components removed from the aircraft to facilitate structural inspection and repair under the PDM process.

3.2.5.1. Visual Inspection and Disposition of Avionics Components: A visual inspection of all avionics components and instruments for evidence of corrosion or physical damage shall be conducted. Avionics and instruments include those items associated with the communication, navigation, performance indication, attitude indication, and mission systems. Any avionics or instruments with external corrosion shall be cleaned and treated IAW T.O. 1H-1-23 and T.O. 1-1-689. If available, environmentally sealed connectors shall be used as replacements. Those avionics and instruments with no visible defects shall be assumed to be operational, and shall be tagged, wrapped in electrostatic discharge material (if applicable), preserved, and stored. In the event the visual inspection reveals suspected defects, then replacement may be required. No avionics component tear-down or repair is authorized.

3.2.5.2. Visual Inspection and Disposition of Components Other than Avionics: A visual inspection of all removed aircraft components and accessories shall be conducted. The following guidance is provided regarding disposition of aircraft parts and components (excluding avionics and instruments) following inspection. Aircraft components include those items associated with the aircraft structure or airframe, or other aircraft systems not categorized as avionics or instruments. Any component with corrosion shall be cleaned and treated. Any component with a safety-of-flight discrepancy shall be repaired. Any component requiring obvious depot-level maintenance may be routed for repair. No component tear-down, overhaul, or repair outside the scope of this work specification is authorized without prior approval from the CFA/CFR. Those items requiring organizational/intermediate-level repairs or questionable depot-level repairs shall be preserved and stored while disposition is determined by the CFA/CFR. Those components with no defects shall be tagged, preserved, and stored.

3.2.6. System and Component Requirements: Table 1 is provided as guidance to determine responsibility for correction of systems/component discrepancies found during DLM.

Table 1. Systems Diagram

Inducted operational?

Disturbed in DLM during inspection/repair/disassembly/ assembly operations?

Operational after

DLM?

Does DLM Correct?

Yes Yes No Yes Yes No No No No Yes No No No No No No

Unknown Yes No Yes Unknown No No No

The steps and procedures concerning preservation that are outlined in the following paragraphs are intended to establish guidelines and expectations. Preservation is to be accomplished IAW the applicable aircraft maintenance manuals.

3.2.7. Aircraft, Avionics and Component Preservation: Aircraft, avionics, and components, requiring removal to facilitate inspection, shall be removed, preserved, and stored IAW the applicable aircraft maintenance manuals. The following paragraphs detail desired policies for the preservation and storage of the TH-1H aircraft, avionics, and associated components during depot-level maintenance. In this document, the TH-1H components to be removed and preserved are classified into five categories: avionics, dynamic components, engine, batteries, and fuel tanks. General storage and preservation requirements for the TH-1H aircraft, avionics, and components are contained in T.O. 1H-1(U)N-17, T.O.1-1-17, T.O. 2J-T53-12, T.O. 00-85A-03- 1, and T.O. 1-1-689.

3.2.7.1. Aircraft Preservation: The depot facility shall determine the type of aircraft storage and preservation required IAW T.O. 1H-1(U)N-17 and T.O. 1-1-17 based on the anticipated delay of aircraft induction or delivery.

3.2.7.2. Dynamic Components Preservation: Preservation of aircraft dynamic components shall be accomplished IAW the applicable aircraft maintenance manual as required.

CAUTION

Extra precautions shall be taken to preserve and store the main transmission due to possible moisture condensation within the assembly and the high susceptibility of the gearbox to corrosion.

3.2.7.3. Engine Preservation: No disassembly of the engine or removal of components is authorized, except to install the engine into approved engine container. All components removed from an engine to facilitate storage shall be tagged, and shall have an inventory link with that engine. Engine components shall not be interchanged without CFA/CFR approval. If an engine, or a sub-component of the engine, is within 10% time/fatigue life limits that require replacement, the depot facility shall notify the CFA/CFR. Engine removal, preservation, shipment, and storage in the appropriate engine storage container shall be IAW T.O. 2J-T53-12, paragraph 5.G. The engine must be stored in a pressurized container. The US Government (USG) will provide a serviceable container for each engine delivery.

3.2.7.4. Fuel Tank Preservation: Preservation and storage of aircraft fuel tanks shall be IAW T.O. 00-85A-03-

1. Coat interior and exterior rubber portions of cell with oil IAW T.O. paragraph 4.7.3.2. Touch up alodine/anodize on fittings as necessary.

3.2.7.5. Avionics Component Preservation: Preservation and storage of aircraft avionics components shall be

IAW T.O. 1-1-689.

3.2.7.6. Deviations: In view of efficiency and effectiveness of the repair process, deviations to preservation and storage requirements may be authorized. However, written justification for any deviation shall be presented to the CFA/CFR for review and approval.

3.2.8. Cleaning the Aircraft: The depot facility shall clean the aircraft IAW T.O. 1H-1(T)H-2-1 and T.O. 1-1- 691 prior to inspection and repair. The purpose of the aircraft cleaning is to expose defects that may not otherwise be noticed during the inspections.

3.3. INSPECTION REQUIREMENTS: The purpose of this section is to establish definitive inspection tasks required to locate and identify all deficiencies, and to determine maintenance and repair requirements.

3.3.1. General Inspection Criteria: The depot facility shall perform a thorough zonal inspection of the aircraft. The inspection requirements for each zone are listed in ascending zone sequence as shown in Figure 1 and Table 2. Each item listed shall be inspected, tested, repaired, reworked, or replaced, as specified, at the designated frequency.

3.3.1.1. Determination if airframe and/or tailboom alignment verification is required under the DLM process unless otherwise directed by the CFA/CFR. If airframe and/or tailboom alignment is required, it shall be verified via the use of a fuselage and/or tailboom alignment fixture. The following conditional inspections/aircrew reports will determine if placement of the fuselage and/or tailboom in an alignment fixture is required. Placement of the fuselage and/or tailboom in an alignment fixture shall be considered work outside of the FFP tasks and shall be estimated, negotiated, approved and charged IAW the contract O&A procedures.

General:

- Vibration. Any persistent/unresolved observed changes in frequency and/or level of aircraft vibration reported by the aircrew. Any persistent/unresolved changes in vibration noticed during changes in speed or during maneuvers reported by the aircrew. Persistent/unresolved vibration could indicate damage to and /or misalignment of the airframe.

- Oscillations. Unusual oscillations reported by the aircrew occurring during landing or shutdown.

Oscillations may indicate damage to landing gear system or landing gear backup structure and/or misalignment of the airframe.

- Stability and Control. Crew reported problems with aircraft stability and control could indicate damage to aircraft’s flight control systems or structural misalignment.

- Load Factor: Any reported excessive flight and/or ground loads placed on the aircraft. Any indication that the aircraft has experienced a hard landing.

Fuselage:

- Inspection of primary airframe structure, and interfacing hardware for signs of overstress such as excessive yielding or buckling. Any wrinkling, distortion, or buckling of skins. Any cracked, bent, twisted pylon structure in the area of the vertical web, horizontal web, and transmission fifth mount attach areas. Any cracks in lift beam cap angles or evidence of oversized/elongated holes in the lift link fitting. All crash damaged aircraft must be placed in the fuselage alignment fixture.

During repair of the fuselage the alignment fixture shall be used for the following conditions unless otherwise directed by the CFA/CFR:

- Aircraft involved in a crash.

- Removal or loosening of primary structure (i.e. longerons, bulkheads, or fittings).

- Removal or loosening of two or more adjoining skins simultaneously.

Tailboom:

- Any deterioration, wrinkling of skin, excessive buckling or other indications which would create doubt as to correct alignment.

During repair of the tailboom the alignment fixture shall be used for the following conditions unless otherwise directed by the CFA/CFR:

- Tailboom removed from a crash damaged aircraft.

- Removal or loosening of primary structure (i.e. longerons, bulkheads, or fittings).

- Removal or loosening of two or more adjoining skins simultaneously.

- Record check incomplete or tailboom history unknown.

3.3.1.2. For those items called out to be replaced 100% that may not be available in supply to support the delivery timeline, contractor may request to inspect removed/used item for serviceability. Upon CFA/CFR approval, contractor shall inspect item for serviceability and reinstall if deemed serviceable.

Figure 1. TH-1H Zone Areas

Table 2. TH-1H Zone Descriptions

Zone Zone Title Zone Description 1 Nose Area All surfaces, components, and equipment in nose compartment and on exterior ahead of crew doors, including the battery, forward electrical compartment, windshield, and lower nose windows.

2 Cabin Area and Landing Gear

All surfaces, components, and equipment inside cabin, and on exterior between forward sides of crew doors (STA 23) and aft cabin walls (STA 166) and pylon island structure (STA 129), includes complete landing gear, but does not include forward fuel cell sumps on cabin underside.

3 Center Fuselage Area All surfaces, components, and equipment in fuselage below engine deck level (WL 54.89), between cabin area and tail boom attachment bulkhead, including fuel cells, forward fuel cells under cabin floor, compartment in pylon island below main transmission, and compartments accessible through side doors on fuselage, oil cooler, and external power distribution.

4 Pylon Area All surfaces, components, and equipment of the main rotor pylon group, from top of mast to bottom of transmission, including main rotor, mast and rotating controls, transmission with accessories and mounts, and main (input) driveshaft.

5 Engine Area All surfaces, components, and equipment associated with engine installation, located above engine work deck (WL 54.89) and within engine cowling, tailpipe fairing, and intake fairing.

6 Tailboom Area All surfaces, components, and equipment located in or on the tailboom and vertical fin structure, including tail rotor synchronized elevator and control linkages, the complete drive train of shaft and gearboxes between main transmission and tail rotor.

3.3.2. Scope of Zonal Inspections: The zonal inspection is a visual inspection for defects; security; cracks;

delamination; wear; chafing; corrosion; damage; dents; non-standard repairs; foreign objects; distortion;

interference; evidence of overheating and leakage; broken or missing parts; loose fasteners; proper lubrication and bonding; out-of-tolerance conditions; and presence and legibility of markings.

a. STRUCTURE. Specific structural inspection tasks are called out in the checklists detailed in the maintenance logs and records, forms and publications section of the PWS. Additional inspection requirements, which typically pertain to isolated mishaps, are listed in the Drop-in Maintenance/Depot Field Team section (Paragraph 4.17) of the PWS. Otherwise the zonal inspection is a visual inspection for defects; corrosion, cracks, distortion, damage, dents, non-standard repairs, loose or missing fasteners, worn or loose bushings, and defective sealant and seals.

b. STRUCTURE, HONEYCOMB AND ADVANCED COMPOSITE. Every panel is to be inspected when removed or opened. Otherwise the zonal inspection is a visual inspection for: cuts, scratches, pits, erosion, abrasion, punctures, cracks, surface ply rips, delamination, dents (i.e. crushed core), and loose or missing fibers around fasteners and/or countersunk holes. Honeycomb panels shall be tapped for delamination, and examined for cracks, corrosion, dents, buckles, punctures, loose fasteners or other damage. Ultrasonic inspection shall be utilized if the extent of delamination cannot be verified during a tap test or if a questionable area is discovered.

c. SKIN. The zonal inspection is a visual inspection for defects: cracks, corrosion, deformation, dents, nicks, scratches, security, and oil canning.

d. ACCESS PLATES, DOORS, PANELS, AND COWLINGS. The zonal inspection is a visual inspection for defects: loose, missing, or defective fasteners, wear on latches and hinges, cracks, corrosion, deformation, and seal integrity (for riveted seals). Tap test honeycomb panels for disbond per paragraph 3.3.2.b. Seals attached with adhesive are to be removed to facilitate inspection, then replaced with new.

e. SCREENS. The zonal inspection is a visual inspection for defects: tears and security.

f. FAIRINGS. The zonal inspection is a visual inspection for defects: cracks and deterioration and loose, missing, or defective fasteners.

g. TRANSPARENT ASSEMBLIES. The zonal inspection is a visual inspection for defects: distortion, scratches, cracks, crazing, delamination, defective sealant and seals; frames for cracks, corrosion, damage, and security.

h. STEPS, LADDERS, AND HANDHOLDS. The zonal inspection is a visual inspection for defects:

cracks, corrosion, distortion, and security.

i. ESCAPE HATCHES/CANOPIES. The zonal inspection is a visual inspection for defects: Inspect transparent assemblies as detailed in paragraph 3.3.2.g. Inspect escape mechanisms for cracks, corrosion, and operation.

j. MECHANICAL LINKAGES AND ACTUATING MECHANISMS. The zonal inspection is a visual inspection for defects: cracks and corrosion, improper alignment and adjustment, damage, and security.

k. CONTROL CABLES, AND FLEXIBLE SHAFTS. The zonal inspection is a visual inspection for defects: corrosion, fraying, chafing, kinks, untwisting, broken strands/wires, security, lubrication, and improper alignment, routing, rigging, and tension.

l. PULLEYS, FAIRLEADS, PRESSURE SEALS, RUBSTRIPS, CABLE END FITTINGS, AND

CONDUIT. The zonal inspection is a visual inspection for defects: wear, improper alignment and adjustment, damage, and security.

m. FLEXIBLE HOSES. Rubber Hoses: Replace with new, all synthetic rubber hoses. Teflon hoses: The zonal inspection is a visual inspection of Teflon hose assemblies for defects: chafing, abrasion, cracking, leaking, corrosion, proper routing, security, and physical integrity. External Wire Braided: The zonal inspection is a visual inspection of the hose. Replace if any of the following conditions exists: Two or more broken wires per plait, more than six broken wires per linear foot, or a broken wire in any position where kinking is suspected. Replace if backed out retaining wires on swivel nuts exist. See Appendix A for mandatory replacements for select hose assemblies.

n. TUBING AND DUCTING. The zonal inspection is a visual inspection for defects: cracks, corrosion, chafing, security, and evidence of leakage, end fittings and clamps for security and proper installation and routing. Remove anti-chafe wrap from rigid hydraulic tubing. See Appendix D for mandatory replacements of select air distribution system components.

o. ELECTRICAL/ELECTRONIC EQUIPMENT. The zonal inspection is a visual inspection for defects in electrical bundles or wiring problems. Visually inspect for evidence of overheating, corrosion, proper bonding and security, defective vibration dampers, missing covers, broken glass, deformed cases, for corroded, exposed, and damaged pins (when disconnected), terminals, connectors, and attaching hardware.

p. WIRING, WIRING COMPONENTS, AND TERMINAL BOARDS. The zonal inspection is a visual inspection for defects: evidence of overheating, kinking, chafing, fraying, deterioration, minimum bend radius, fluid damage, and proper routing, splices, terminals, and connectors (when disconnected) for damaged pins, deteriorated potting, and security.

q. INSTRUMENTS. The zonal inspection is a visual inspection for defects: evidence of overheating of electrical units, damaged faceplates, interference with moving parts, security of units, and attached wiring, hoses, and tubing.

r. ANTI-FRICTION BEARINGS. The zonal inspection is a visual inspection for defects: (unless otherwise specified) accessible anti-friction bearings of mechanisms, control systems, engine control linkages, rod ends, pulleys, etc., for damage. General inspection and servicing of aircraft bearings shall be accomplished IAW T.O. 1H-1(T)H-2-1, as required.

s. RADOMES AND ANTENNA COVERS. The zonal inspection is a visual inspection for defects: cracks, erosion, improper patching with electrically opaque material, improper sealing, obvious misalignment, security, corrosion, wire tension, and loose connectors.

t. DRIVESHAFTS. The zonal inspection is a visual inspection for defects: cracks and corrosion, evidence of improper alignment and adjustment, damage, and security.

u. MECHANICAL FLIGHT CONTROLS. The zonal inspection is a visual inspection for defects and problems. Inspect bearings for roughness, binding, wear, security, and freedom of operation. Inspect brackets for damage and security. Inspect flight control rods for damage or chafing through entire range of motion. Inspect flight control rods for water contamination by shaking rods. Inspect fixed and adjustable length control rods, torque tubes, spring assemblies, supporting structure, flex joints, mounts, and guides for: loose, missing, and improperly installed hardware, corrosion, distortion, cracks, and security of installation. Inspect clevis, adapters, and clevis pins for nicks, scratches, and corrosion.

v. COMMUNICATION SYSTEMS. The DLM team will perform an operational verification of all communication components utilized by this electronic system to verify the ability of the aircraft/component wiring to perform its intended function mated to a set of operational components.

Operational verification shall be accomplished by operational test of the system using the existing aircraft components, if operable; otherwise the tests cannot be completed. Operational tests shall be limited to the depth required to demonstrate the adequacy of systems function.

w. EQUIPMENT MOUNTS. The zonal inspection is a visual inspection for defects: corrosion, security, nicks, scratches, dents, excessive wear, cracks, damage, and enlargement of fastener holes.

x. FUEL LINES AND FITTINGS. The zonal inspection is a visual inspection for defects: cuts, nicks, dents, damage, leaks, and security. Check date of manufacture on fuel lines and check breakaway valves for serviceability. Replace IAW T.O. 1H-1(T)H-2-1 and T.O. 42E1-1-1 as required. See paragraph 3.3.2.m.for flexible hose inspection/replacement criteria. Mandatory replacement of select hose assemblies are specified in Appendix A.

y. HYDRAULIC LINES AND FITTINGS. The zonal inspection is a visual inspection for defects: cuts, kinks, chafing, leaks, nicks, dents, damage, and proper routing and clamping. See paragraph 3.3.2.m. for inspection/replacement criteria of flexible hoses. Mandatory replacement of select hose assemblies are specified in Appendix A.

z. HYDRAULIC ACTUATORS, MECHANISMS, AND COMPONENTS. The zonal inspection is a visual inspection for defects: leaks, cracks, wear, corrosion, damage, security, and evidence of improper alignment.

3.3.3. Zone 1: Nose Area

REQUIREMENT

Zonal Inspection Perform zonal inspection of Zone 1 IAW paragraph 3.3.2.

Inspect skin for cracks, corrosion, distortion, loose and missing rivets and fasteners.

Inspect structure for cracks, distortion, corrosion and damaged screw holes and fastener receptacles.

Honeycomb Panels Inspect the following honeycomb panels for cracks, corrosion, dents, buckles, punctures, loose fasteners, delamination, or other damage.

1. Upper Nose Shelf (P/N 3H1153-10). (P/N 3H1153-10 is a modified P/N 205-530-509-103 shelf.)

2. Lower Nose Shelf (P/N 3H1152-10). (P/N 3H1152-10 is a modified P/N 205-530-510-101 shelf.)

3. Upper Nose Door (P/N 212-030-348-103)

4. Lower Nose Aft Panel, Searchlight (P/N 212-030-206-1)

5. L/H Upper Nose Panel (P/N 212-030-079-119)

6. R/H Upper Nose Panel (P/N 212-030-079-120)

Upper Nose Door Inspect door hinge brackets and attaching structure for cracks and corrosion.

Perform 100% seal replacement IAW T.O. 1H-1(T)H-2-1. Perform water intrusion check(s). Adjust as necessary. If water intrusion persists, report findings to engineering for further direction.

Lower Nose Door Inspect door hinge brackets and attaching structure for cracks and corrosion.

Perform 100% seal replacement IAW T.O. 1H-1(T)H-2-1. Perform water intrusion check(s). Adjust as necessary. If water intrusion persists, report findings to engineering for further direction.

Avionics Shelves Inspect electrical component and mounting attachment points to shelves for cracks, corrosion, delamination, dents, and punctures; loose, missing, and corroded fasteners.

Examine the mounts and attachment structure for corrosion, cracks, and missing/loose hardware. Inspect doublers for delamination and corrosion.

Inspect shelf brace angles for cracks.

Windshields and Windows Inspect windshield and windows for scratches, pits, cracks, holes, and crazing.

Inspect windshield posts for cracks.

Inspect windshield wiper arms for deterioration, security, and serviceability. Replace blades.

3.3.4. Zone 2: Cabin Area and Landing Gear

Zonal Inspection Perform zonal inspection of Zone 2 IAW paragraph 3.3.2.

Inspect skin for cracks, corrosion, distortion, loose and missing rivets and fasteners.

Inspect structure for cracks, distortion, corrosion, and damaged or oversized fastener holes and receptacles.

Honeycomb Panels Inspect the following honeycomb panels for cracks, corrosion, dents, buckles, punctures, loose fasteners, delamination, or other damage.

1. Center fuel cell forward panel, STA 155.06 (P/N 205-030-200-79)

2. Center fuel cell lower panel, STA 155 to 178 (P/N 205-030-396-087/-089)

3. Intercostal Panel, L/H Forward (“Coffin”) Fuel Cell, STA 102.00 to STA 155.06, LBL 37 (P/N 205- 030-209-19)

4. Intercostal Panel, R/H Forward (“Coffin”) Fuel Cell, STA 102.00 to STA 155.06, RBL 37 (P/N 205- 030-209-20)

5. L/H roof deck panel, STA 63.38 to 168.50 (P/N 205-030-602-55)

6. R/H roof deck panel, STA 63.38 to 168.50 (P/N 205-030-602-50)

7. Center roof deck panel, STA 63.38 to 126.81 (P/N 205-030-126-51)

8. Intercostal, L/H Door Post, WL 38.60 (P/N 205-031-272-1)

9. Intercostal, R/H Door Post, WL 38.60 (P/N 205-030-278-1)

10. L/H Door Post Panel, STA 63.38 to 74.25 (P/N 205-031-271-1)

11. R/H Door Post Panel, STA 63.38 to 74.25 (P/N 205-030-277-49)

Structure Inspect L/H and R/H main beam cap angles, for wear, corrosion, elongated holes and cracks.

Inspect main beam angles and fittings for cracks, corrosion, and working fasteners.

Inspect L/H and R/H forward upper main beam Tee caps, WL 22 BL 14, for cracks. Pay particular attention to the area just forward of pylon, STA 129. Perform fluorescent penetrant inspection of cap at STA 129 ± 4 inches. If previously repaired, check for security of the repair doubler and angle.

Inspect forward landing gear horseshoe support fittings and surrounding area for cracks, deformation, and wear; loose, missing and defective fasteners.

Replace forward cargo door track assemblies (STA 63.38 to 168.50):

1. L/H upper (WL 72.60), P/N 205-030-220-007

2. L/H lower (WL 22.00), P/N 205-030-385-019

3. R/H upper…