Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Raytheon Model Beech 400A and 400T series airplanes. This proposal would require replacement of the low-pressure oxygen tubing located in the forward fuselage (nose avionics bay), lower forward flight deck, and lower forward cabin areas, as applicable, with new low-pressure oxygen tubing. This action is necessary to prevent leakage of oxygen from scored low-pressure oxygen tubing, which could result in lack of available oxygen for the flightcrew, or possible explosion or fire. This action is intended to address the identified unsafe condition.