Document ID: chunk:federal_register_of_legislation:F2006B08801:body:0:p1
Version: federal_register_of_legislation:F2006B08801
Segment Type: other
Provision Reference: 
Character Range: 4–3219

Douglas DC3 Series Aeroplanes

    AD/DC3/26
    Amdt 2

    Wing Centre Section Structure at NK Stn 141-142 - Inspection and Modification

    Applicability: All models DC3 and C47.

                 Requirement: 1. Outer Wing Panel Lower Surface Attachment Angles and Attachment Angle Doublers: Modification:

                 Replace the lower surface attachment angle and light gauge doublers, P/N 570602- 206 and -207 or P/N 5115200-206 and -207 of .064-in. material and 570602-208 and -209 or P/N 5115200-208 and -209 of .051-in. material with heavy gauge doublers, P/N 570602-206 and -207 or P/N 5115200-206 and -207 of .072-in.
                 material and 570602-208 and -209 or P/N 5115200-208 and -209 of .064-in. material and mating attachment angles, or with heavy gauge doublers P/N 524128- 1400, -1401, -1402 and -1403 and mating attachment angles.

               Note: It is imperative that the above modification should be carried out strictly in accordance with the recommended procedures and practices of Douglas Aircraft Company and that the highest standard of workmanship and accuracy should be maintained throughout.

                 2.    Centre Section Lower Surface Skin - Modification:

                   (a)     Provided for the inspection of the centre section skin by cutting six 5/8-in. diameter inspection holes in the internal doublers as shown in Figure 1 of Douglas SB DC3. No. 262, Re-issue No. 2, 6 December 1963.

                   (b)     Modify the centre section lower surface by installing new wrap around doublers and attachment angles in accordance with the above Douglas SB, or to an equivalent scheme approved by the Secretary, except that modifications made prior to the issue of this Order in accordance with Douglas Drawing 5406787 Issue "E" or "F" are satisfactory until parts must again be replaced.

               Note: It is imperative that the highest standard of workman-ship and accuracy should be maintained throughout.

                 3.    Outer Wing and Centre Section Upper and Lower Attachment Angles, Attachment Angle Bolts and Spar Cap Bolts at Stations 141-142 - Inspection:

                      (a)     (i) With the aid of a lens of not less than X8 magnification, inspect the upper and lower attachment angles for cracks and evidence of corrosion, paying particular attention to the radius and to the areas between the bolt holes.

                      (ii)     Visually inspect the attachment angle bolts for evidence of looseness or breakage.

                      (iii)  Visually inspect the spar cap bolts for evidence of looseness of breakage.

                   (b)     At every fourth inspection:

                  (i)       If any signs of corrosion are detected in the attach angles remove all paint and other organic finishes and thoroughly clean the attachment angles prior to carrying out the inspection contained in para. 3(a).

                  (ii)     Remove each 10th attach angle bolt as a sample and inspect removed bolts for corrosion and general condition. Identify removed bolts before reinstallation and select different samples at each subsequent inspection.

                  (iii)  Check that the attach