Description: time spent on the preventive maintenance of the engine; Name: preventive maintenance period
Description: part of maintenance time when preventive maintenance is carried out on an item, including technical, logistic and internal administrative delay; Name: preventive maintenance time
Description: determined through a surface, product of the sound pressure, p, and the component of the particle velocity, un, at a point on the surface in the direction normal to the surface, integrated over that surface; Name: sound power