Airworthiness Directive · Amendment 39-14183 · Boeing Model 707-300B, -300C, and -400 Series Airplanes
Boeing Model 707-300B, -300C, and -400 Series Airplanes
This AD applies to all Boeing Model 707-300B, -300C, and -400 series airplanes, certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for all Boeing Model 707-300B, -300C, and -400 series airplanes. This AD requires repetitive inspections to detect cracked or broken hinge fitting assemblies of the inboard leading edge slats, and corrective action if necessary. This AD also provides as an option a preventive modification, which defers the repetitive inspections. In addition, this AD provides an option of replacing all hinge fitting assemblies with new, improved parts, which terminates the repetitive inspection requirements. This AD is prompted by results of a review to identify and implement procedures to ensure the continued structural airworthiness of aging transport category airplanes. We are issuing this AD to detect and correct fatigue cracking of the hinge fitting assembly of the inboard leading edge slats, which could result in reduced structural integrity of the slat system. This condition could result in loss of the inboard leading edge slat and could cause the flightcrew to lose control of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
In this AD, the term “service bulletin” means the Accomplishment Instructions of Boeing 707/720 Service Bulletin 2982, Revision 2, dated October 7, 1977.
Before the accumulation of 10,000 total flight hours, or within 1,500 flight hours after the effective date of this AD, whichever occurs later, do a dye penetrant inspection to detect cracked or broken hinge fitting assemblies of the inboard leading edge slats in accordance with Part I, “Inspection Data,” of the service bulletin. Repeat the inspection at intervals not to exceed 1,500 flight hours, except as provided by paragraph (i) or (k) of this AD.
If any crack or broken assembly is found during any inspection required by paragraph (g) of this AD, before further flight, do the action specified in paragraph (h)(1), (h)(2), or (h)(3) of this AD.
(1) Replace the hinge fitting assembly with a like serviceable part in accordance with Part I of the service bulletin.
(2) Replace the hinge fitting assembly with a like serviceable part on which the preventative modification specified in paragraph (i) of this AD has been done, in accordance with Part II of the service bulletin. This replacement defers the repetitive inspection requirements of paragraph (g) of this AD for 15,000 flight hours for that hinge fitting assembly.
(3) Replace the hinge fitting assembly with a new, improved part in accordance with Part III of the service bulletin. This replacement terminates the repetitive inspection requirements of paragraph (g) of this AD for that hinge fitting assembly.
Note 1: For this AD, a “like serviceable part” is a serviceable part listed in the “Existing” part number column of Table II of the service bulletin that has been inspected and found to be crack free in accordance with paragraph (g) of this AD before installation. A “new part” is a part listed in the “Replacement” or “Optional” part number column of Table II of the service bulletin.
(i) Doing a preventative modification by accomplishing all the procedures in Part II of the service bulletin, except as required by paragraph (j) of this AD, defers the repetitive inspections required by paragraph (g) of this AD. Within 15,000 flight hours after the preventive modification, do the repetitive inspections in paragraph (g) of this AD at intervals not to exceed 1,500 flight hours.
(j) If any crack is found during the preventative modification specified in paragraph (i) of this AD, before further flight, do the action specified in paragraph (h) of this AD.
Replacement of a hinge fitting assembly with a new, improved part terminates the repetitive inspection requirements of paragraph (g) of this AD for that assembly. Replacement of all hinge fitting assemblies with new, improved parts terminates the repetitive inspection requirements of this AD. The replacement must be done in accordance with Part III of the service bulletin.
Actions accomplished before the effective date of this AD using Boeing 707/720 Service Bulletin 2982, Revision 1, dated June 29, 1970, are considered acceptable for compliance with the corresponding action in this AD.
