71-11-08 MCDONNELL DOUGLAS: Amdt. 39-1217. Pursuant to the authority of the Federal Aviation Act of 1958, delegated to me by the Administrator, the following airworthiness directive, applicable to all operators of Douglas DC-9 and Military C-9A airplanes, was effective immediately upon receipt of telegram dated May 10, 1971. \n\n\tBecause of repeated incidents of the pilot's or first officer's instrument panel assemblies sliding aft; and in one instance, producing control column interference, one of the following alternate actions is to be accomplished within 25 flight hours in service after receipt of this telegram: \n\n\t(1)\tInstall placard on captain and first officer instrument panel stating "Check panel security before takeoff." Or \n\n\t(2)\tIncorporate a check item in flight crew aircraft acceptance check list stating "Check security of captain and first officer instrument panels." Or \n\n\t(3)\tIn the maintenance program include security of captain and first officer instrument panel as a "required inspection item" whenever the panels are disturbed, subject to the approval of the assigned principal inspector. \n\n\t(4)\tSecondary safety latches may be installed in accordance with Douglas Service Bulletin 31-16, dated October 14, 1969, or later FAA approved revision. Accomplishment of this modification will constitute of itself compliance with this AD. \n\n\tEquivalent methods of compliance must be referred to the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\tThis amendment becomes effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated May 10, 1971.