The smoke detected was from a leak of diesel fuel on to a hot diesel engine surface. There was no fire. A small bore fuel line had fractured at a radial bend in the tubing as it entered a ferrule fitting. The failure was as a result of stress, impact and the high vibration environment. The radial bend was of the incorrect dimensions and the support was not sufficiently robust. Evidence of impact could be seen on the assembly
• Incorrectly designed and installed fuel line after maintenance
• Radial bend dimensions pre-stressed the tubing at the ferrule.
• High vibration loads on the pre-stressed tubing led to the fracture
• Changes in design should be managed through the management of change procedure
• Introduce enhanced training and competence for those working with small bore tubing
Diesel fuel line