70-14-03\tBOEING: Amdt. 39-1024 as amended by Amendment 39-1093 and 39-1123 is further amended by Amendment 39-1144. Applies to all Model 747 airplanes certificated in all categories. \n\tCompliance required within the next 10 landings after the effective date of this AD, unless already accomplished within the last 90 landings and thereafter at intervals not to exceed 100 landings from the last inspections. \n\tTo detect cracks of the flap track, accomplish the following: \n\t(a)\tWithin 10 landings after the effective date of this AD, unless already accomplished within the last 90 landings, visually inspect all flap tracks for cracks in accordance with Boeing Alert Service Bulletin 57-2011, Revision 1, dated June 6, 1970, or later FAA approved revisions, or in a manner approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\t\t(1)\tIf a crack is found, replace flap track or repair in accordance with a method approved by the Chief, Aircraft Engineering Division, FAA Western Region, prior to further flight. Repeat inspections, per (a) (2) below. \n\t\t(2)\tIf no cracks are found, repeat the inspection for cracks at intervals not to exceed 100 landings. \n\t(b)\tWithin 10 hours after the effective date of this AD, unless already accomplished, install a placard as noted below in full view of the captain and first officer, or provide an equivalent procedure acceptable to the cognizant Air Carrier District Office. \n\tPlacard wording is as follows: \n\n\t\t\t\t Recommended \n\t\t Flap\t\t Flap Operating Speed \n\t\tPosition\t\t(Knots IAS)\t \n\t\t 25\t\t 170 \n\t\t 30\t\t 140 \n\n\t(c)\tReport in the airplane log all instances when the flap speeds in (b) above are exceeded. \n\t(d)\tUpon accomplishment of (c), visually inspect all inboard flap tracks for cracks per (a), prior to further flight. \n\t\t(1)\tIf a crack is found, replace or repair the flap track per (a)(1). Repeat inspections per (a)(2). \n\t\t(2)\tIf nocracks are found, repeat inspections per (a)(2). \n\t(e)\tInstall placard advising pilot of reporting requirements specified in paragraph (c). \n\t(f)\tThe existing flap tracks may be replaced with redesigned flap tracks in accordance with Boeing Service Bulletin 57-2100, Revision 4, dated November 25, 1970, or later FAA approved revision or in a manner approved by the Chief, Aircraft Engineering Division, FAA Western Region. Upon completion of this modification, the inspection and placard installation requirements of paragraphs (a) through (e) are no longer applicable. \n\tAmendment 39-1024 effective July 21, 1970. \n\tAmendment 39-1093 effective October 22, 1970. \n\tAmendment 39-1123 effective December 11, 1970. \n\tThis Amendment 39-1144 becomes effective January 19, 1971.