Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to supersede Airworthiness Directive (AD) 2008-26- 07, which applies to all McDonnell Douglas Model DC-8-11, DC-8-12, DC- 8-21, DC-8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, and DC-8-43 airplanes; Model DC-8-50 series airplanes; Model DC-8F-54 and DC-8F-55 airplanes; Model DC-8-60 series airplanes; Model DC-8-60F series airplanes; Model DC-8-70 series airplanes; and Model DC-8-70F series airplanes. AD 2008-26-07 currently requires repetitive inspections of the lower skin and stringers at certain stations, and corrective actions if necessary. This proposed AD is intended to complete certain mandated programs intended to support the airplane reaching its limit of validity (LOV) of the engineering data that support the established structural maintenance program. This proposed AD would also require an eddy current high frequency (ETHF) inspection for cracks of the fastener open holes common to the lower skins, stringers, and splice fittings at a certain station; installation of external doublers and fasteners and repetitive eddy current low frequency (ETLF) inspections around the fasteners for any crack; and corrective actions if necessary. We are proposing this AD to detect and correct cracks in the lower skins, stringers, and fastener holes of the splice fittings, which could result in the loss of structural integrity of the airplane.