Bulgaria – Aircraft-engine repair services – Извършване на основен ремонт на два броя газотурбинни двигатели (ГТД) тип MARS 90

The subject of this contract is the performance of a major overhaul of two gas turbine engines (GTE) of type MARS 90, including the following activities according to the technical specification, namely: - Dismantling of the existing two GTE MARS 90 from the composition of GTEC No. 8 from the CS "Lozenez" and GTEC No. 3 from the CS "Petrich"; - Transport of the engines from CS "Lozenez" and CS "Petrich" to the repair base of the contractor; - Disassembly, defect detection, major repair, restoration, replacement of parts and assembly of the engines; - Transport of the engines back from the contractor's repair base to CS "Lozenez" and respectively to CS "Petrich" to the Client; - Installation and 72-hour testing under operational conditions of the engines; - Submission of a final report on the results of the repair of the GTEs; - Warranty maintenance within the warranty period. The gas turbine engines were manufactured and supplied by Solar Turbines Incorporated, headquartered in San Diego, California, USA. They were commissioned in 2016, respectively in the composition of GTEC No. 8 in compressor station "Lozenez" and GTEC No. 3 in compressor station "Petrich". The engines are model MARS 90 with machine identification ME2BEA-1100-270, which determines their technical characteristics, operational parameters and specific maintenance requirements according to the manufacturer's instructions. At this point, the engines have reached a service life close to 30,000 operating hours. This operational threshold is of significant importance, as according to the manufacturer's service concept, it represents a boundary at which a major overhaul is necessary. This requirement is due to the accumulated wear of the main units and components operating under high thermal and mechanical loads, which can lead to deterioration of the operational characteristics and increased risk of emergency events. The major overhaul includes a complete disassembly of the engines, detailed diagnostics and assessment of the condition of all key components, replacement or restoration of worn elements, subsequent assembly, balancing and testing. Through the performance of these activities, the aim is to restore the original technical parameters of the engines, including power, efficiency and reliability of operation. The performance of the repair is necessary in order to ensure safe, reliable and failure-free operation of the equipment within the gas transmission infrastructure. Additionally, according to the manufacturer's instructions, a successfully completed major overhaul will allow the extension of the operational life of the engines until the total service life of approximately 60,000 operating hours is reached.