Summary
We propose to adopt a new airworthiness directive (AD) for certain Model 737-900ER series airplanes. This proposed AD would require doing a one-time general visual inspection for a keyway in two fuel tank access door cutouts, and related investigative and corrective actions if necessary. This proposed AD results from reports of cracks emanating from the keyway of the fuel tank access hole. We are proposing this AD to detect and correct such cracking, which could result in the loss of the lower wing skin load path and consequent structural failure of the wing.