A cage can include a thermal plate positioned so as to be aligned with a bottom of a channel. Each recess has a housing which contains pressure in the channel. A pair of floatation pontoons is releasably attached to the passenger cabin. A shaft is coupled to the rotor. In this weight detecting apparatus weight detecting apparatus, the mounting conditions of the weights are detected by wireless communications between the ID reader and the ID tags. If a femoral component is not locked to the pad, the post of the instrument moves from an exposed position proximal to the proximal pad surface to a retracted position distal to the proximal pad surface, thereby permitting impaction.