Airworthiness Directives; Learjet Model 45 Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Learjet Model 45 airplanes. This action requires pulling the FOOT WARM circuit breaker located on the copilot's circuit breaker panel, and installing a collar on that circuit breaker. This action is necessary to prevent an electrical short circuit between the pilot's and copilot's foot warmers and the composite floorboards, which could result in outgassing of the faceply material of the composite floorboards, and consequent smoke in the cockpit. This action is intended to address the identified unsafe condition.