Bahrain CAA Part-66 AME Exam cheat sheet

Bahrain CAA is the national civil aviation authority; it adopts EASA-style Part-66/Part-145 rules under its own Bahrain Civil Aviation Regulations (BCARs), so always cite the BCAR reference in force, not the EU number.

Part-66 licence categories: A (line maintenance certifying support), B1 (mechanical), B2 (avionics), B3 (light non-pressurised aeroplanes), plus C for base maintenance certification; each category has its own privilege set.

Basic experience requirements for initial B1/B2 certification are typically 2 years practical maintenance experience (or 1 year plus an approved Part-147 course); A category is generally 1 year (or 6 months with approved training).

A certifying staff authorisation is issued by the Part-145 organisation; the licence alone does not authorise certification - both the licence and the company authorisation are required.

Type ratings are endorsed on the licence after demonstrating experience and examination; the licence must be endorsed for the specific type before certifying that type.

Continuing airworthiness is the responsibility of the registered owner/operator through an approved CAMO; the maintenance organisation supports it via the maintenance programme approved by the CAA.

Aircraft maintenance records must be retained so the airworthiness status can be traced: typically 2 years for detailed maintenance records and the full airworthiness life for life-limited parts and major repairs/modifications.

Occurrence reporting: serious incidents and defects must be reported to the CAA within the timeframes set in the regulations (commonly 72 hours for serious occurrences, 30 days for others) - the maintenance organisation's MOE defines the internal escalation.

SHELL model: Software, Hardware, Environment, Liveware (the person at the centre) - mismatch at any interface creates error; Liveware-Liveware is usually the most critical interface in maintenance.

Dirty Dozen error precursors: lack of communication, complacency, lack of knowledge, distraction, lack of teamwork, fatigue, lack of resources, pressure, lack of assertiveness, stress, lack of awareness, norms.

The 'error chain' concept: errors are usually the result of a chain of latent conditions plus active failures; breaking any link (e.g. via a checklist or second check) prevents the outcome.

Fatigue: performance degrades with cumulative sleep loss; circadian low points are roughly 03:00–06:00 and 15:00–17:00 local, when error rates rise even for experienced staff.

Complacency typically follows repeated routine tasks; countermeasures include varying the sequence, using written task cards, and independent inspection of critical steps.

Communication: use closed-loop (read-back) confirmation for verbal instructions and record all shift handovers in writing; ambiguity in handover is a leading cause of maintenance error.

Stress: moderate arousal improves performance (Yerkes-Dodson), but high stress narrows attention and increases omission errors; recognise personal stress signals early.

Situational awareness: the 'three-level' model - perception of cues, comprehension of meaning, projection of future state; loss of SA often precedes an incident by minutes.

Primary flight controls: ailerons (roll), elevators (pitch), rudder (yaw); secondary controls include flaps, slats, spoilers, trim tabs, and leading-edge devices.

Hydraulic system pressures are typically 3000 psi (approx. 207 bar) on transport aircraft; always depressurise and verify zero pressure before opening a hydraulic line.

Pressurisation: cabin differential pressure is limited by the pressure relief valve and the outflow valve; max differential is typically around 8–9 psi for transport aircraft.

Landing gear: oleo strut servicing uses nitrogen (or dry air) and hydraulic fluid; correct extension/compression and strut inflation are checked against the AMM servicing chart.

Structural inspection: corrosion-prone areas are lap joints, seat tracks, bilge areas, and battery compartments; use the SRM for allowable damage limits and the AMM for inspection intervals.

Composite structures: damage classification (delamination, impact, porosity) requires NDT (tap test, ultrasonic, thermography); repair limits are defined in the SRM, not general practice.

Fire detection: engine/APU fire loops use resistance or capacitance change with temperature; a loop fault typically shows as a fault light and must be tested before flight.

Ice and rain protection: pitot/static heaters, wing anti-ice (thermal or pneumatic), and windshield heating are checked for correct current draw and continuity during pre-flight checks.

Gas turbine cycle: intake, compression, combustion, exhaust; thrust is produced by accelerating mass flow (Brayton cycle), and specific fuel consumption improves with higher compression ratio and turbine inlet temperature.

Turbofan vs turbojet: high-bypass turbofans move most air through the bypass duct, giving better propulsive efficiency and lower noise at typical cruise speeds.

Engine starting: starter (air turbine or electric) drives the HP compressor; ignition is selected during start, and fuel is introduced after reaching the required N2 (or N1) percentage.

Engine parameters monitored: N1 (fan/LP spool), N2 (HP spool), EGT/ITT, fuel flow, oil pressure/temperature, and vibration; exceedances require AMM/SRM action.

Fuel system: LP and HP fuel pumps, fuel control unit / FADEC metering, and fuel/oil heat exchanger; contamination checks (water, sediment, microbial growth) are routine.

Oil system: pressure and scavenge pumps, oil cooler, and chip detectors; a chip detector warning requires inspection per the AMM before further flight.

Ignition: typically two igniter plugs and exciter boxes; continuous ignition is used for takeoff, landing, and adverse weather; igniter wear is checked by gap and condition.

Propeller (where fitted): constant-speed units use a governor to vary blade pitch; feathering, reverse, and beta range functions are tested per the AMM, and blade track/balance checks apply.

DC power: battery (typically 24 V lead-acid or NiCd) and starter-generator; NiCd batteries require specific electrolyte and ventilation precautions and separate servicing from lead-acid.

AC power: 115 V AC 400 Hz is standard on transport aircraft; generated by IDGs or APU generator; the CSD/IDG maintains constant frequency.

Bus systems: main, essential, and emergency buses; the essential bus remains powered by the battery through the static inverter or TRU when main AC is lost.

Bonding and grounding: low-resistance bonds (typically < 2.5 milliohms for primary structure) protect against lightning and static discharge; check with a bonding meter.

Wiring practices: use the standard wiring practices manual (SWPM) for splice, connector, and routing; never exceed bend radius or use unapproved terminals.

ESD precautions: wear a wrist strap and use grounded mats when handling LRUs and circuit cards; store sensitive electronics in anti-static bags.

Inspection of electrical connectors: check for corrosion, arcing, loose pins, and correct torque; use the specified insertion/extraction tools to avoid pin damage.

Fault diagnosis: use built-in test equipment (BITE) and the aircraft maintenance manual fault isolation charts; do not substitute parts without confirming the fault path.

Maintenance documentation hierarchy: AMM (maintenance), SRM (structural repair), IPC (illustrated parts), WDM (wiring), CMM (component); always use the current revision applicable to the aircraft.

Work cards/task cards must be signed off after completion; any deviation from the approved data requires an approved engineering disposition (e.g. a repair scheme or minor/major modification approval).

Torque: use calibrated torque wrenches within their calibration validity; apply the specified torque value and record it; never use an extension that changes the effective lever arm without recalculation.

Locking and safetying: use lockwire, cotter pins, or self-locking nuts per the AMM; lockwire must be twisted in the correct direction and terminate correctly.

NDT methods: visual, dye penetrant, magnetic particle, eddy current, ultrasonic, and radiography; each has a specific material applicability and requires certified personnel.

Release to service: after maintenance, a certificate of release to service (CRS) is issued by authorised certifying staff confirming the work was done per approved data.

Fuel tank safety and confined-space entry: follow the AMM/OSHA-equivalent entry procedures, gas-free certification, and rescue arrangements before entering tanks.

Foreign object debris (FOD) control: tool control, area sweeps, and pre-close inspections of intakes, engine bays, and control cavities prevent FOD damage.