Cyclic

Inspect engine controls per Chapter 76.

### Rigging Verification Procedure 1.

**Fuel control unit (FCU) rigging:** a.

## 76-20-00 Fuel Control Unit Inspection ### Procedure 1. Inspect the fuel control unit (FCU) mounting for security.

Inspect the FCU input lever and linkage for wear, corrosion, and freedom of movement.

Inspect fuel lines to and from the FCU for chafing, leaks, and security.

--- # Chapter 79 — Engine Oil System ## 79-10-00 Spectrometric Oil Analysis ### General Spectrometric oil analysis (SOA) is a critical tool for monitoring engine internal wear.

### Sample Collection Procedure 1.

Obtain the sample from the engine oil tank drain valve using a clean sample bottle.

## 79-10-00 Engine Oil Filter Inspection ### Procedure 1. Remove the engine oil filter bowl assembly from the oil filter housing (located on the accessory gearbox).

Cut the filter element using an approved oil filter cutting tool.

## 79-20-00 Engine Chip Detector Inspection ### Procedure 1. Remove the engine chip detector plug from the accessory gearbox sump (lower location).

Inspect the magnetic plug for metallic particles.

### Borescope Inspection Procedure (100-Hour) 1. Remove the borescope inspection plugs from the engine case (two plugs: one for the first-stage gas generator turbine and one for the first-stage power turbine).

Insert a rigid or flexible borescope and inspect the first-stage gas generator turbine wheel: - Blade tips: Look for tip erosion, burning, or curling.

## 72-20-00 Interstage Seal and Exhaust Stack ### Inspection 1. **Interstage seals:** During the borescope inspection, observe the interstage seal area between the gas generator turbine and power turbine.

**Exhaust stack inspection:** a.

Inspect cabin structure for cracks, corrosion, loose rivets, and deformation. Pay particular attention to the lower cabin skin at station 108.0 and station 136.0 where fatigue cracking has been observed in service. Refer to SB 407-53-108 for updated inspection criteria.

Inspect all windows and windshield for crazing, delamination, and security of attachment. Windshield panels shall be replaced if any crack exceeds 2.0 inches in length or if crazing reduces pilot visibility below acceptable limits.

Inspect landing gear skid tubes, crosstubes, and saddles for damage, distortion, and security. Check crosstube-to-saddle bolt torque at 150-175 in-lbs. Refer to Chapter 20-00-00 for torque values.

Inspect all doors and latches for proper operation. Door hinge pins shall show no wear exceeding 0.005 inches on the pin diameter.

Inspect tailboom attachment bolts for proper torque (350-400 in-lbs) and safety wire. Inspect tailboom skins for cracks, dents, and corrosion, especially in the area of the horizontal stabilizer attachment at station 267.0.

Inspect horizontal stabilizer for cracks, debonding, and mounting bolt security. Mounting bolt torque: 80-100 in-lbs.

Inspect swashplate assembly for wear, corrosion, and freedom of movement. Check swashplate bearing play per the limits in the Component Maintenance Manual.

Inspect hydraulic system for leaks, reservoir level, and filter condition. Hydraulic fluid: MIL-PRF-83282. Reservoir capacity: 1.5 quarts. Minimum fluid level for dispatch: 1.0 quart.

Inspect electrical system including battery, generator, bus bars, and circuit breakers. Battery specific gravity: 1.275-1.300 when fully charged.

Inspect pitot-static system for blockage and leaks. Perform altimeter correlation check per 14 CFR 91.411 if required.

Inspect fuel system, including cells, lines, valves, and fuel filter. Drain fuel filter/water separator bowl. Check fuel boost pump operation.

Inspect flight controls for full travel, freedom of movement, and proper rigging. All control rod end bearings shall be checked for wear.

### 12-10-00 Lubrication Chart — 100-Hour Items The following lubrication points shall be serviced at intervals not exceeding 100 flight hours: 1. **Main rotor spindle bearings (4 locations):** Apply MIL-PRF-81322 grease through the zerk fitting on each spindle.

**Main rotor pitch link rod ends (8 bearings):** Apply MIL-PRF-81322 grease to each rod end bearing.

**Swashplate bearings (upper and lower):** Apply MIL-PRF-81322 grease through the zerk fittings on the swashplate support.

## 12-20-00 Fluid Levels and Servicing ### Hydraulic Reservoir 1.

Remove the filler cap and check fluid level on the sight glass.

### Transmission Oil 1.

Inspect main transmission per Chapter 63-10-00. Check oil level, chip detectors, and external condition.

### 100-Hour Inspection Procedure 1. **External visual inspection:** Inspect the transmission housing for cracks, leaks, and security of mounting.

3. **Chip detector inspection:** a.

Inspect freewheeling unit per Chapter 63-20-00.

### Inspection Procedure 1. With the engine at idle, disengage the rotor brake and observe main rotor RPM.

4. **Oil filter inspection:** a. Remove the transmission oil filter bowl assembly.

Remove the filter element and inspect for metallic contamination.

Inspect main rotor blades per Chapter 62-10-00. All four blades shall be inspected for erosion, cracks, delamination, and impact damage.

### 100-Hour Inspection Procedure 1.

**Leading edge erosion strip inspection:** Examine the full length of the titanium erosion strip from root to tip. Look for: - Pitting deeper than 0.020 inches - Erosion strip separation or delamination from the blade surface - Leading edge nicks exceeding 0.125 inches in depth - Any den

Inspect main rotor hub assembly per Chapter 62-10-00. Check yoke for cracks using dye penetrant or fluorescent penetrant methods per Bell Process Specification BPS-4005.

## 62-10-00 Main Rotor Hub Inspection ### 100-Hour Inspection Procedure 1. Inspect the hub yoke assembly for cracks, corrosion, and mechanical damage. Pay particular attention to the spindle-to-yoke junction area.

Inspect pitch link assemblies per Chapter 62-20-00. Check rod end bearing play; replace bearing if axial play exceeds 0.010 inches.

## 62-20-00 Pitch Link Assembly Inspection 1. Inspect each pitch link rod end bearing for wear. Check for axial play by grasping the rod end and attempting to move it along the axis of the bolt. Replace the bearing if axial play exceeds 0.010 inches.

Inspect lead-lag dampers per Chapter 62-30-00 for fluid leaks and proper charge pressure.

## 62-30-00 Lead-Lag Damper Inspection 1. Inspect each elastomeric lead-lag damper for: - Fluid leaks: Any visible fluid weeping from the damper body requires damper replacement.

Inspect engine installation per Chapter 71-10-00.

### 100-Hour Inspection Procedure 1. **Engine cowling and firewall:** Remove engine cowling panels.

2.

## 71-20-00 Compressor Wash ### Purpose Compressor performance degrades over time due to contaminant buildup on the compressor blades and vanes.

### Procedure 1.

## 71-30-00 Fuel Nozzle Inspection ### Procedure 1. Remove the fuel nozzle from the combustion liner.

Inspect the nozzle tip for carbon buildup, erosion, and cracking.

Check the spray pattern by connecting the nozzle to a calibrated fuel flow bench.

## 71-40-00 Igniter Plug Inspection ### Procedure 1. Remove both igniter plugs from the combustion liner.

Inspect each igniter plug for: - Electrode erosion: Replace if the center electrode has eroded to within 0.040 inches of the shell.

### 05-10-00 100-Hour / Annual Inspection Card The following inspection tasks shall be accomplished at intervals not to exceed 100 flight hours or 12 calendar months, whichever occurs first. All discrepancies noted during the inspection shall be corrected prior to return to service.

### Table 20-1: Standard Torque Values | Bolt Size | Fine Thread (in-lbs) | Coarse Thread (in-lbs) | |-----------|---------------------|----------------------| | #8-32 | 18-20 | 15-17 | | #10-32 | 30-35 | 25-30 | | 1/4-28 | 75-85

### Installation Procedure 1.

--- # Chapter 20 — Standard Practices ## 20-00-00 Torque Values ### General Torque Requirements Unless otherwise specified, all bolts, nuts, and screws shall be torqued in accordance with Table 20-1.

All critical fasteners shall be torqued using a calibrated torque wrench.

Inspect tail rotor gearbox per Chapter 65-20-00. Check oil level and magnetic chip detector.

### 100-Hour Inspection Procedure 1.

**Oil level check:** Remove the oil level check plug (pipe plug at the 3 o'clock position on the gearbox).

Inspect tail rotor driveshaft and hanger bearings per Chapter 65-10-00.

### 100-Hour Inspection Procedure 1. **Driveshaft section inspection:** Inspect each driveshaft segment for: - Dents: No dent deeper than 0.020 inches is acceptable on any driveshaft tube.

2.

Inspect tail rotor blades per Chapter 64-10-00.

### 100-Hour Inspection Procedure 1.

**Leading edge inspection:** Examine the stainless steel erosion strip for: - Dents exceeding 0.060 inches in depth - Erosion that exposes the composite substrate - Separation of the erosion strip from the blade body Minor dents and nicks less than 0.060 inches deep may be blended sm

Inspect tail rotor pitch change mechanism per Chapter 64-10-00.

## 64-10-00 Pitch Change Bearings and Crosshead ### Inspection Procedure 1. Inspect the tail rotor pitch change bearings (2 per blade, 4 total) for: - Freedom of rotation: The bearing must rotate smoothly with no roughness or binding.

Perform vibration survey per Chapter 18-10-00.

### Equipment Required - Chadwick-Helmuth Vibrex 4000 or Aces Systems 2100 (or equivalent) - Accelerometer kit with mounting hardware - Reflective tape for blade tracking - Stroboscope (Strobex or equivalent) ### 18-10-00 Main Rotor Track and Balance Procedure 1. Install the accelerometer on the

## 18-20-00 Vibration Survey — Tail Rotor 1. With the main rotor at 100% Nr, record the tail rotor 1-per-rev vibration at the tail boom accelerometer station (station 260.0).