AD 2001-02-08 Amendment 39-12092

This amendment adopts a new airworthiness directive (AD), applicable to all Short Brothers Model SD3-60 SHERPA, SD3-SHERPA, SD3- 30, and SD3-60 series airplanes, that requires replacement of the existing pneumatic de-icing boot pressure indicator switch with a newly designed switch. This amendment is prompted by an occurrence on a similar airplane model in which the pneumatic de-icing boot indication light may have provided the flightcrew with misleading information as to the proper functioning of the de-icing boots. The actions specified by this AD are intended to prevent ice accumulation on the airplane leading edges, which could reduce controllability of the airplane.