Summary
The FAA proposes to supersede an existing airworthiness directive (AD) for all Boeing Model 767-200, -300, and -300F series airplanes. That AD currently requires examination of maintenance records to determine if Titanine JC5A (also known as Desoto 823E508) corrosion inhibiting compound ("C.I.C.") was ever used; inspection for cracks or corrosion and corrective action, if applicable; repetitive inspections and C.I.C. applications; and modification of the aft trunnion area of the outer cylinder, which terminates the need for the repetitive inspections and C.I.C. applications. This proposed AD would also require, for certain other airplanes, repetitive inspections for cracks or corrosion, corrective action if necessary, and repetitive C.I.C. applications. This proposed AD is prompted by a report that JC5A was used on more airplanes during production than previously identified. We are proposing this AD to prevent severe corrosion in the main landing gear (MLG) outer cylinder at the aft trunnion, which could develop into stress corrosion cracking and consequent collapse of the MLG.