Summary
The FAA is revising an earlier proposed airworthiness directive (AD) for certain Raytheon Model HS.125 series 700A airplanes, BAe.125 Series 800A airplanes, and Model Hawker 800 and Hawker 800XP airplanes. The original NPRM would have required an inspection to determine the current rating of the circuit breakers of certain cockpit ventilation and avionics cooling system blowers; and replacing the circuit breakers and modifying the blower wiring, as applicable. The original NPRM was prompted by a report indicating that a blower motor seized up and gave off smoke. This action revises the original NPRM by clarifying the compliance time and removing a reporting requirement. We are proposing this supplemental NPRM to prevent smoke and fumes in the cockpit in the event that a blower motor seizes and overheats due to excessive current draw.