Airworthiness Directives; The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP Series Airplanes

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD would require repetitive inspections for damage of the electrical terminal at the left and right flightdeck window 1, and corrective actions if necessary. This proposed AD would also allow for replacing the flightdeck window 1 with a new improved flightdeck window equipped with different electrical connections, which would terminate the repetitive inspections for that flightdeck window 1. This proposed AD was prompted by several reports of electrical arcs at the terminal blocks of the electrically heated flightdeck window 1. We are proposing this AD to prevent smoke and fire in the cockpit, which could lead to loss of visibility, and injuries to or incapacitation of the flightcrew.