Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Saab Model SAAB-Fairchild SF340A (SAAB/SF340A) and SAAB 340B airplanes. This proposed AD would require a one-time inspection to see if a faulty uplock axle for the shock strut of the main landing gear (MLG) is installed, and replacing the uplock axle with a new uplock axle if necessary. This proposed AD results from a report of a cracked uplock axle caused by hydrogen embrittlement during the manufacturing process. We are proposing this AD to prevent failure of the uplock mechanism, which, combined with a loss of hydraulic pressure, could result in an uncommanded extension of the MLG.