Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Dassault Model Mystere-Falcon 50, Mystere-Falcon 900, and Falcon 900EX series airplanes. This proposal would require revising the Emergency Procedures and Abnormal Procedures sections of the airplane flight manual to advise the flightcrew to immediately don oxygen masks in the event of significant pressurization or oxygen level changes. This action is necessary to prevent incapacitation of the flightcrew due to lack of oxygen, which could result in their inability to continue to control the airplane. This action is intended to address the identified unsafe condition.