Summary
The FAA proposes to supersede Airworthiness Directive (AD) 2009-01-02, which applies to certain Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. AD 2009-01-02 requires an inspection of frames between body station (BS) 360 and BS 907 to determine if certain support brackets of the air conditioning (A/C) outlet extrusions are installed, inspections for cracking of the frames around the attachment holes of the subject brackets, and repair if necessary. AD 2009-01-02 also requires installing new, improved fittings for all support brackets of the A/C outlet extrusions between BS 360 and BS 907. Since the FAA issued AD 2009-01-02, the agency determined that certain repairs might develop fatigue cracks that could result in the inability of the frame to sustain limit load and therefore must be inspected. This proposed AD would continue to require the actions specified in AD 2009-01-02 and would also require repetitive inspections for cracking of certain repairs and repair if necessary. The FAA is proposing this AD to address the unsafe condition on these products.