Summary
We propose to adopt a new airworthiness directive (AD) for certain Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This proposed AD would require modifying the thrust reverser inner walls, inspecting for damage of the upper and lower inner wall insulation blankets, measuring the electrical conductivity on the aluminum upper compression pads 2 and 3 as applicable, inspecting for discrepancies of the inner wall of the thrust reverser, and corrective actions if necessary. This proposed AD would also require, for certain airplanes, doing various concurrent actions (including replacing the inner wall blanket insulation, installing updated full-authority digital electronic control software, and modifying the thrust reverser inner wall and insulation blankets). This proposed AD results from reports of heat damage to the inner wall of the thrust reversers. We are proposing this AD to detect and correct such heat damage, which could result in separation of adjacentcomponents and consequent structural damage to the airplane, damage to other airplanes, and injury to people on the ground.