Maintenance Safety Tip – The “B” Nut can be Deadly
The “B” Nut can be Deadly All aircraft maintainers have heard or used the term “B” nut. It is the common description of the nut that is used to connect fluid lines and hoses. It is a very simple component; but does a critical job. It provides a reliable seal in plumbing systems and usually results in ease of maintenance for AMTs. It is designed to provide years of reliable service. However, “B” nut reliability is only as good as how you treat it. We disconnect and connect them many times during our careers - right? However, do you “tighten”
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