50-23-02 DOUGLAS: Applies to All Model DC-6 Aircraft. \n\n\tTo be accomplished as indicated below: \n\n\t1.\tAll P/N 5245424 and P/N 5248748 nose gear yoke end fittings which have not been shotpeened in the journal radius prior to original installation or by subsequent rework should be removed for inspection after being in service for a period not to exceed 6,000 hours. Nose gear yoke end fittings which have already accumulated service time in excess of 6,000 hours should be removed for inspection as soon as practical but not later than September 1, 1950. Shotpeening can be distinguished by the dull gray color and coarse surface of the shotpeened area. \n\n\t2.\tFittings removed at the 6,000-hour period may be used for an additional 4,000 hours or a total service life of 10,000 hours if inspected and reworked as follows: \n\n\t\t(a)\tStrip anodic surface from part, and subject to Zyglo inspection paying particular attention to the journal radius. If no cracks are found, the radius should be polished to remove all blemishes and then shotpeened. This inspection and shotpeening must be done by the Douglas Aircraft Co., an agency approved by that company, or by a method that has been substantiated as being equivalent to the procedure recommended by the Douglas Co. \n\n\t\t(b)\tInspect the base radius of the spot faces of the six mounting holes. Parts having zero radius (sharp corner) to 0.031 radius at this point must be reworked to obtain an 0.062 spot face radius. It will be permissible to increase the original spot face diameter of 1 1/8 inches to 1 1/4 inches to obtain the 0.062 radius. Parts having 0.031 or better radius need not be reworked. Parts should be reanodized after completion of all work. \n\t\t(c)\tInspect the inside diameter of the 2103390 ring. All sharp edges should be given a 0.031 radius. \n\t\t(d)\tInspect the inside diameter of the flanged end of the 2333253 bushing to see that it has a 1/8-inch radius and rework if necessary. \n\n\t3.\tFittings shotpeened at time of original installation may be operated for a maximum service period of 10,000 hours provided they do not have the zero spot face radius at the mounting holes. Parts falling in this category should be removed at the normal gear overhaul period of 8,000 hours for rework of the spot face radius. \n\n\t4.\tAll fittings should be scrapped after reaching a total service life of 10,000 hours. \n\n\t(Douglas General Service Letter DC-6 No. 26 dated April 7, 1950, covers the same subject.)