Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 757-200, -200PF, and -200CB series airplanes. This proposed AD would require doing an ultrasound inspection for disbonded tear straps not mechanically fastened to the skin, and related investigative and corrective actions, if necessary. This proposed AD results from reports indicating that bonded skin panels may not have been correctly anodized in phosphoric acid before the tear strap doubler was bonded to the skin. We are proposing this AD to detect and correct a weak bond between the skin and tear strap. Such disbonding could reduce the ability of the skin to resist cracks and could adversely affect the structural integrity of the airplane.