77-10-12 MCDONNELL DOUGLAS: Amendment 39-2906. Applies to Model DC-8 Series airplanes, certificated in all categories. \n\n\tCompliance required within the next 300 hours time in service or 30 days after the effective date of this AD, whichever comes first, unless already accomplished within the past 30 days. \n\n\tTo detect cracks and prevent failure or jamming of the elevator geared tab crank arm and gust lock assemblies, comply with the following: \n\n\t(a)\tVisually inspect both the left and right side inboard and outboard elevator geared tab crank arm assemblies, P/N's 4710541 and 4710542 for failure and/or cracks. \n\n\t(b)\tVisually inspect the P/N 5644178 gust lock assembly, and specifically, the torque tube section of the P/N 4644181 crank assembly, for failure and/or cracks. \n\n\t(c)\tFailed or cracked parts must be replaced with like serviceable parts before further flight. \n\n\t(d)\tVerify that clearance exists between the crank assemblies, P/N 4710541 and 4710542, and the boxsection for all positions along elevator travel. \n\n\tNote: McDonnell Douglas DC-8 Alert Service Bulletin A27-262, dated April 28, 1977, covers the same subject. \n\n\t(e)\tSpecial flight permits may be issued in accordance with FAR's 21.197 and 21.199 to authorize operation of an airplane to a base to perform the inspections required by this AD. \n\n\tThis amendment becomes effective May 26, 1977.