Date: 201904
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: SF 340B
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Parked
Aircraft component: Fuel Line; Fittings; & Connectors
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Time Pressure; Training / Qualification; Workload
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Aircraft In Service At Gate
Result: General None Reported / Taken
Contributing factors: Aircraft; Company Policy; Human Factors
Primary problem: Human Factors

Narrative: During a flight crew swap of Aircraft X in ZZZ1; the Captain described a maintenance incident that occurred upon arrival in ZZZ. A passenger informed the flight attendant that large amounts of liquid were pouring out from the right engine. After deplaning; maintenance was requested; the local FBO mechanic was notified and addressed the issue. The engine was ran and fuel was spraying from the top of the engine. The action taken to fix this damage was to just slide the metal sleeve over the rubber fuel transfer line and secure the coupling. The engine was run again with no apparent leaking; however there was not an Inspector present to verify or sign off this maintenance action and the aircraft was signed off in ZZZ then operated to ZZZ1. When the aircraft arrived in ZZZ1; the logbook had a history of discrepancy write ups concerning fuel leaking from the right engine. I then asked the ZZZ1 Maintenance to inspect the right engine as I did not agree with the action taken to address these right ups nor the action taken in ZZZ. Two ZZZ1 mechanics opened the front engine compartment of the right engine nacelle and told me it was safe to operate. Further review of past write ups and corrective actions with the ZZZ1 mechanic; from previous mechanics; the ZZZ1 mechanic then stated that several of the corrective actions described did not make sense to include write ups concerning fuel leaking from the right engine. It was at this point I determined that this aircraft was not safe to operate due to the unclear sign offs from other mechanics and that there was not an inspector sign off for a fuel related repair as is states in the MM-01 regarding the repair done earlier in ZZZ. What was then discovered in ZZZ1; under the metal sleeves; were the fuel transfer lines saturated in fuel which led to them expanding double the correct size causing fuel leaking. Every fuel transfer line surrounding the hot section was saturated in fuel with tears in the hoses and were covered up by the metal sleeves. The write ups concerning fuel leaking was misdiagnosed and blatantly signed off as ops checks ok on several occasions over a period of several days.  Flight crews pay close attention to maintenance write ups in the logbook and perform thorough pre and post flights to ensure the aircraft is safe to operate.




Synopsis: Flight crew reported that incorect maintenance was performed to fix an engine fuel leak.