Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 747 airplanes. This proposed AD would require modifying the inflation systems of the upper deck escape slides; single-piece off-wing escape ramps/slides; two-piece off-wing escape slides; and door 1, 2, 4, and 5 escape slides/rafts. This proposed AD is prompted by a report of 30- to 60-second delays in the inflation of escape slides/rafts. We are proposing this AD to prevent actuation delays in the inflation systems of the escape slides/rafts, which could result in delayed or failed deployment of escape slides/rafts during emergency evacuation of an airplane.