Transport i lotnictwo · 18.10.1995

14 CFR Part 39

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all Aerospatiale Model ATR- 42 and ATR-72 series airplanes. Unless modifications are accomplished or alternative procedures and training are adopted, that AD currently prohibits operation of the airplane in certain icing conditions, and requires restrictions on the use of the autopilot in certain conditions. That AD was prompted by an FAA determination that, during flight in certain icing conditions, and with the airplane in a specific flight configuration, a ridge of ice can form on the wing and cause an interruption in the airflow over the ailerons, aileron deflection, and resultant lateral control forces. The actions specified by that AD are intended to prevent a roll upset from which the flight crew may be unable to recover. This action would add requirements for modification of the deicing boots on the leading edge of the wing and various follow-on actions.