Airworthiness Directives; Boeing Model 737-300, 737-400, 737-500, 737-600, 737-700, 737-800, 757-200, 757-200PF, 757-200CB, and 757-300 Series Airplanes

Streszczenie

This document proposes the adoption of a new airworthiness directive (AD) that would apply to certain Boeing Model 737-300, 737- 400, 737-500, 737-600, 737-700, 737-800, 757-200, 757-200PF, 757-200CB, and 757-300 series airplanes. This proposal would require a test of the two electrical circuits that close the fuel shutoff valve on the wing spar, and repair, if necessary. This action is necessary to prevent inability to shut off the flow of fuel to an engine after an uncontained engine failure, which could result in a fire spreading to other parts of the airplane. This action is intended to address the identified unsafe condition.