Summary
This document withdraws a notice of proposed rulemaking (NPRM) that would have applied to all Short Brothers & Harland Ltd. (Shorts) Models SC-7 Series 2 and SC-7 Series 3 airplanes. The proposed AD would have required you to revise the Airplane Flight Manual (AFM) to include requirements for activation of the airframe pneumatic deicing boots. The proposed AD was the result of reports of in-flight incidents and an accident (on airplanes other than the referenced Shorts airplanes) that occurred in icing conditions where the airframe pneumatic deicing boots were not activated. Since issuing this NPRM, we have found that all of the affected airplanes incorporate a freezing point fluid system. These airplanes do not have pneumatic deicing boots. Therefore, we have determined that the unsafe condition defined in the NPRM does not exist on these airplanes and we are withdrawing the NPRM.