Maintenance & fault isolation

Access · Battery compartment access panel

Tools & materials · Digital multimeter · Battery capacity tester · Terminal cleaning kit · Torque wrench

Warning · A NiCd battery with rising temperature or falling voltage trend can indicate incipient thermal runaway — do not return a suspect battery to service without shop test.

1. 1.Battery master OFF; disconnect battery per AMM sequence (negative first on removal).
2. 2.Inspect the battery box for corrosion/electrolyte residue; clean and neutralise as required.
3. 3.Check terminal condition, inter-cell connections (NiCd) and vent/drain paths are clear.
4. 4.Perform or schedule a capacity check per AMM interval; check individual cell voltages if applicable.
5. 5.Reinstall and reconnect per AMM sequence, torque terminals, verify no BATT FAULT caution on power-up.

Ref: H145 AMM 24-30-00

Access · Fuel filter housing, each engine supply line

Tools & materials · Filter wrench · New O-rings/seals · Fuel sample container

Warning · A popped bypass indicator means fuel has been flowing unfiltered to the engine — do not clear the indication without inspecting and, if needed, replacing the element.

1. 1.Confirm fuel shutoff valve CLOSED for the line being serviced; relieve any residual pressure per AMM.
2. 2.Remove the filter bowl/element and inspect the bypass (clog) indicator button position.
3. 3.Inspect the filter element for contamination (water, debris, microbial growth); clean the bowl.
4. 4.Install a new element/seals as required; reinstall and torque per AMM.
5. 5.Reopen the shutoff valve, run an engine or boost pump per AMM to check for leaks and confirm the bypass indicator resets.

Ref: H145 AMM 28-20-00

Access · Hydraulic reservoirs, upper fuselage/MGB deck

Tools & materials · Flashlight · Approved hydraulic fluid

Warning · Never mix hydraulic fluid types — contamination can damage seals across both systems.

1. 1.With the system in the depressurised/ground state specified by the AMM, read each reservoir's sight gauge or electrical level indication.
2. 2.Compare to the minimum mark for System 1 and System 2 independently — do not assume one reading applies to both.
3. 3.Top up with approved fluid if below minimum; do not mix fluid types.
4. 4.Check for external leaks at reservoir fittings, lines and servo-actuators.
5. 5.Record readings; investigate any system showing a trend of fluid loss.

Ref: H145 AMM 29-00-00

Access · Skid tubes, cross tubes, ground

Tools & materials · Flashlight · Inspection mirror · Torque wrench for attachment fittings

Warning · Any suspected hard or hard-side landing requires the AMM hard-landing inspection before further flight, even if the skid gear looks superficially normal.

1. 1.Visually inspect skid tubes for dents, scoring, abrasion from ground contact, and corrosion.
2. 2.Inspect cross tube attachment fittings to the fuselage for cracking, loose fasteners, and correct torque striping.
3. 3.Check ground-handling wheel attachment points (if fitted) and any skid shoes/wear plates for wear.
4. 4.Inspect for signs of a hard landing (cross tube bowing, fuselage skin wrinkling near attachments) and cross-reference with any hard-landing inspection requirement.
5. 5.Record findings; defer per AMM damage limits or escalate to a hard-landing inspection if indicated.

Ref: H145 AMM 32-00-00

Access · Main rotor blades, ground, rotor stopped

Tools & materials · Flashlight · Inspection mirror · Blade damage limit chart

Warning · Never rotate the rotor by hand to inspect a blade without confirming engines are shut down and all ignition/battery switches are set per the AMM ground-handling procedure.

1. 1.Visually inspect each blade leading edge erosion strip for nicks, disbonding and lightning strike damage.
2. 2.Check blade skin for delamination, cracking, or impact damage, especially near the root flexbeam area.
3. 3.Inspect tip cap and balance weights for security.
4. 4.Check drain holes (if fitted) are clear.
5. 5.Compare any damage found against the AMM blade damage limit chart; record and defer or repair as required.

Ref: H145 AMM 62-10-00

Access · MGB access panel, upper fuselage

Tools & materials · Flashlight · Chip detector removal tool · Clean lint-free cloth

Warning · A persistent or repeat chip indication is a flight-safety item — do not dispatch without following the AMM/RFM fault isolation procedure.

1. 1.Check MGB oil sight gauge/level sensor reading against minimum mark.
2. 2.Remove each chip detector plug per AMM; inspect for metal particles.
3. 3.If debris found, identify material (ferrous/non-ferrous) and compare against AMM acceptance criteria.
4. 4.Reinstall plug with new seal, torque and safety per AMM.
5. 5.Record findings; escalate per AMM if chips exceed limits.

Ref: H145 AMM 63-21-00

Access · Tail fin Fenestron duct, ground

Tools & materials · Flashlight · Inspection mirror · Torque wrench for access panels

Warning · Keep hands and tools clear of the duct interior until it is confirmed the rotors cannot be moved — residual rotation energy and inadvertent engagement are hazards.

1. 1.Remove/open the fin access panel as required for the inspection level.
2. 2.Visually inspect each Fenestron blade for leading-edge erosion, impact damage, and pitch-horn security.
3. 3.Check the duct/shroud interior for cracks, delamination and foreign object debris between blades and duct wall.
4. 4.Check blade pitch-change spider and linkages for play and correct lubrication.
5. 5.Close and secure panels; record findings.

Ref: H145 AMM 64-10-00

Access · Tail boom access panels along drive shaft run

Tools & materials · Flashlight · Bearing play-check tooling per AMM · Torque wrench

Warning · A worn or failed hanger bearing can lead to drive shaft whip and eventual loss of tail rotor (anti-torque) drive — treat findings outside limits as a no-go item.

1. 1.Open tail boom access panels along the length of the tail rotor drive shaft.
2. 2.Check each hanger bearing support for security, cracking of the mount, and excess radial play in the bearing.
3. 3.Inspect drive shaft couplings for correct alignment and fretting/wear at splines or flexible couplings.
4. 4.Check for oil/grease leakage or lack of lubrication at bearings requiring it.
5. 5.Reinstall panels; run engines/rotors per AMM and check for abnormal drive-line noise or vibration if a bearing was serviced.

Ref: H145 AMM 65-20-00

Access · Engine air intake, ground, engine cold or per AMM procedure

Tools & materials · Approved compressor wash fluid/kit · Wash rig/sprayer · Demineralised water for rinse

Warning · Skipping the clean-water rinse can leave corrosive residue in the compressor — always complete the full wash-and-rinse cycle.

1. 1.Confirm engine condition per AMM (cold motoring wash or running wash as specified for the Arriel 2E).
2. 2.Protect electrical connectors/sensitive components per AMM masking instructions.
3. 3.Introduce approved wash fluid into the intake while motoring the engine (starter, no fuel/ignition) per the AMM cycle.
4. 4.Follow with a clean water rinse cycle to remove residual detergent.
5. 5.Motor/dry per AMM before the next engine start; perform a ground run and check parameters (NG, TOT, TRQ trend) afterward.

Ref: H145 AMM 72-00-00 / Arriel 2E engine manual

Access · Engine cowling open, each engine

Tools & materials · Flashlight · Approved oil (per AMM)

Warning · Hot oil can cause burns; allow proper cool-down before opening the cowl.

1. 1.Engine shut down, allow oil to settle per AMM wait time.
2. 2.Open the engine cowl and read the sight gauge/dipstick for each engine.
3. 3.Top up with approved oil if below the minimum mark; do not overfill.
4. 4.Check for oil staining/leaks around the accessory gearbox and chip detector plug.
5. 5.Close cowl, secure fasteners, record quantity added.

Ref: H145 AMM 79-00-00