Summary
We propose to adopt a new airworthiness directive (AD) for all The Boeing Company Model DC-6, DC-6A, C-118A, R6D-1, DC-6B, and R6D-1Z airplanes. This proposed AD was prompted by a report of a fuel leak in a Model C-118A airplane that resulted from a crack in the wing lower skin. This proposed AD would require repetitive radiographic, electromagnetic testing high frequency (ETHF), and electromagnetic testing low frequency (ETLF) inspections for cracking of the wing lower skin, and repairs if necessary. We are proposing this AD to detect and correct fatigue cracking in the wing lower skin, which could adversely affect the structural integrity of the wing.