70-23-03\tBOEING: Amendment 39-1105 as amended by Amendment 39-1115. The following airworthiness directive, applicable to all operators of Boeing 747 airplanes is effective immediately upon receipt of telegram dated October 23, 1970. Because of three reported incidents of the pilot's or first officer's instrument panel assemblies sliding aft and 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\t(1)\tInstall placard on captain and first officer instrument panel stating "Check panel security before take-off." Or \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\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\tEquivalent methods of compliance must be referred to the Chief, Aircraft Engineering Division, FAA Western Region. \n\tAs an alternative action to (1), (2), or (3), secondary safety latches may be installed in accordance with Boeing Service Bulletin 31-2005, dated November 13, 1970, or later FAA approved revision. Accomplishment of this modification will constitute of itself compliance with this AD. \n\tAmendment 39-1105 became effective upon publication in the Federal Register for all person except those to whom it was made effective immediately by telegram dated October 23, 1970. \n\tThis amendment 39-1115 becomes effective December 4, 1970.