Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Lockheed Model L-188A and L- 188C series airplanes. This proposal would require revising the Airplane Flight Manual to provide the flightcrew with modified procedures and limitations for operating in icing conditions. This proposal is prompted by incidents and accidents involving airplanes equipped with turboprop engines that experienced tailplane stall due to ice accretion on the horizontal stabilizer of the airplane. The actions specified by the proposed AD are intended to prevent undetected accretion of ice on the horizontal stabilizer, which could result in ice contaminated tailplane stall and consequent loss of pitch control.