Power 

Generation

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.

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 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.

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.

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.