Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Aerospatiale Model ATR42-200, -300, -320, and -500 series airplanes and all ATR72 series airplanes. This proposal would require revision of the Airplane Flight Manual (AFM) to modify procedures for takeoff when Type II or IV de-icing fluids have been used. This proposal is prompted by reports that use of these de-icing fluids is associated with an increase in the pitch forces necessary to rotate the airplane during takeoff and with other changes in performance. These changes could result in reduced controllability of the airplane. The action specified in this AD is intended to ensure that the flight crew is advised of the potential effects of Type II or IV de-icing fluids on the airplane's performance during takeoff and of the procedures necessary to address these effects.