Abstract: Methods, apparatus, computer programs, and non-transitory computer readable storage mediums for repairing an aerofoil of a gas turbine engine A method of repairing an aerofoil of a gas turbine engine, the method comprising: controlling machining of at least one of: a first aerofoil and a second aerofoil; the machining causing an increase in a throat area defined by the first aerofoil, the second aerofoil, a first platform and a second platform, the first aerofoil and the second aerofoil being arranged to couple to the first platform and to the second platform; and controlling provision of a coating to at least one of the first platform and the second platform subsequent to controlling machining to reduce the throat area.

Abstract: An internal combustion engine includes separated oil drain-back and crankcase ventilation passages. The oil drain-back passages extend from the cylinder head to a position below the top level of oil in the engine's crankcase. The crankcase ventilation passages extend from passages formed in the main bearing bulkheads from positions above the oil level in the crankcase and ultimately through the cylinder head. Oil dams surrounding the uppermost portions of the crankcase ventilation passages prevent oil from running downwardly through the crankcase ventilation passages.