Airworthiness Directives; Raytheon (Beech) Model MU-300, MU-300-10, 400, 400A, and 400T Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Raytheon (Beech) Model MU-300, MU-300-10, 400, 400A, and 400T series airplanes, that requires a one-time inspection to detect hydraulic fluid leakage from the B-nut area, which attaches a hydraulic tube to the anti-skid valve assembly, and corrective actions, if necessary; and installation of an additional support for the hydraulic tube. This amendment is intended to prevent an asymmetric braking condition and a longer stopping distance due to sudden loss of normal braking to the left wheel. Such loss of normal braking could result in the airplane overrunning the runway surface. This action is intended to address the identified unsafe condition.