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Generation
Our expertise encompasses constant-frequency AC systems and DC generation, including variable frequency, constant frequency, and high voltage. See us for CSD and starter/generator support.
Electrical Power System Expertise
Four Star Accessory Overhaul provides specialized power generation accessory overhaul services for generators, alternators, and integrated drive units. These components supply the electrical power essential to every aircraft system, from avionics to environmental control.
Power Generation Components
Four Star provides specialized overhaul and repair services for aircraft power generation systems, including generator control units (GCUs), starter-generators, alternators, and power conversion units. These components convert mechanical energy into the stable electrical power that supports every aircraft system, from avionics to environmental control.
Aircraft Power Generation Unit Overhaul
Our overhaul process integrates mechanical and electrical expertise, covering complete disassembly, component inspection, bearing and seal replacement, rotor and stator testing, and comprehensive load and performance verification. We service constant- and variable-frequency AC systems, DC generators, and power electronics that maintain precise voltage, current, and frequency regulation under all conditions.
Power Generation Experts
Our experienced technicians are equipped with specialized tools and test equipment to overhaul and test complex power generation systems including CSDs and starter/generators.
From routine maintenance to complete overhaul, we ensure your aircraft's electrical power systems operate reliably.
Generator Control Unit (GCU) Repair
Our technicians perform Generator Control Unit diagnostics and repair to address voltage regulation issues, load sharing imbalances, and system protection faults. Using simulated generator signals and electronic testing equipment, we ensure each control unit operates reliably across both normal and fault conditions. Modern GCUs include microprocessor-based controls and advanced protection algorithms, and our team maintains the expertise and tooling to test and validate these complex systems.
Starter Generator & Alternator Overhaul
Four Star’s starter generator repair services restore dual-function units used on turboprops and APUs to like-new reliability. Each overhaul includes bearing replacement, commutator or brush service, winding inspection, and dual-mode testing to verify performance in both starting and generating operation. We also perform aircraft alternator overhaul services, addressing bearings, brushes, diodes, and regulators to maintain efficient DC output and long service life.
Our Comprehensive
Service Guarantee
Power Conversion Unit Repair
Our power conversion unit repair capabilities cover transformer-rectifier units (TRUs), inverters, and frequency converters that convert between AC and DC power. These high-power systems are tested under realistic load conditions to confirm output stability, thermal integrity, and compliance with aerospace electrical standards.
Modern turbofan engines drive multiple accessories through gearboxes that power generators, hydraulic pumps, and other vital systems. Four Star provides specialized overhaul and testing for engine-mounted accessories, addressing the performance and reliability challenges these high-demand environments create.
Testing & Validation
Four Star’s power generation test facilities are equipped with advanced load banks capable of applying full-rated electrical loads while precisely monitoring voltage regulation, frequency stability, current capacity, and efficiency. Testing replicates real-world operating conditions with resistive, inductive, and capacitive elements to confirm performance and identify potential thermal or voltage irregularities before components return to service.
Load Bank Testing & Certification
Our technicians perform load testing from no-load to full output, verifying generator and control system performance across the entire range. Temperature and electrical readings ensure proper cooling, minimal ripple, and consistent voltage and frequency control under simulated flight conditions.
All repairs and overhauls are completed under our FAA and EASA power generation repair authorizations, following OEM or FAA-approved data. Every unit is released with airworthiness certification (FAA Form 8130-3 or EASA Form 1), detailed test documentation, and full parts traceability to guarantee compliance and reliability.
Need Expert Support for Your Power Systems?
From CSD overhaul to starter/generator testing, our certified team delivers reliable results.
Four Star’s power generation expertise integrates with our broader accessory capabilities to ensure reliable performance across electrical, mechanical, and control systems. Many power issues originate beyond the generator itself, including gearbox faults, wiring problems, or load management errors. Our system-level diagnostics identify these root causes and provide clear, actionable solutions that prevent repeat failures.
System-Level Support
For operators managing multiple electrical systems, we offer coordinated inspection and testing to uncover patterns across generators, batteries, and control units. From single-generator aircraft to complex widebody transports, we help maintain dependable electrical performance across every platform.
Common Questions
About Power Generation
Repair And Refurbishment
