Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Saab Model SAAB 2000, SAAB SF340A, and SAAB 340B series airplanes. This proposal would require replacing the main pitot static tube on each side of the airplane with a new improved pitot static tube, and installing a gasket between the tube and the airplane structure. This action is necessary to prevent ice from blocking the pitot system, due to the pitot tube not having enough heating capacity to stay above freezing temperature, which could result in erroneous airspeed indications This action is intended to address the identified unsafe condition.