NTSB Safety Alert: Mechanics, The “B” Nut can be Deadly!
"B-nut" is a common term for a nut that provides the clamping force to create a reliable seal in lines (fuel, oil, or air, lines on a reciprocating or turbine engine) installed on an aircraft. If a B-nut is improperly secured (either torqued too much or not enough), a loss of engine power or an engine fire could result. Under- and over-torqued B-nuts could cause fuel, oil, or air leaks depending on where the B-nuts are installed; over-torqued B-nuts could also result in deformation and damage to a line. Fuel or oil leaked onto a hot engine could result in