Summary
We propose to supersede Airworthiness Directive (AD) 2012-05- 03, which applies to certain The Boeing Company Model 747-100, 747- 100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes. AD 2012-05-03 currently requires modifying the fluid drain path in the leading edge area of the wing. Since we issued AD 2012-05-03, Boeing has informed us that it did not provide work instructions to seal two of the drainage holes in the wing leading edge area. This proposed AD would require additional work to seal those drainage holes in the wing access panels. We are proposing this AD to address the unsafe condition on these products.