Airworthiness Directive · Amendment 39-13897 · Boeing Model 707 Airplanes and Model 720 and 720B Series Airplanes
Boeing Model 707 Airplanes and Model 720 and 720B Series Airplanes
This AD applies to all Boeing Model 707-100 long body, -200, -100B long body, and -100B short body series airplanes; and Model 707-300, -300B, -300C, and -400 airplanes; and Model 720 and 720B series airplanes; certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for all Boeing Model 707 airplanes and Model 720 and 720B series airplanes. This AD requires repetitive inspections of the left and right support ribs for the main landing gear (MLG) trunnion, related investigative/ corrective actions if necessary, and other specified actions. This AD is prompted by reports of in-service cracking of the support ribs for the MLG trunnion. We are issuing this AD to detect and correct corrosion and cracking of the support ribs for the MLG trunnion, which could result in collapse of the MLG.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
The term “alert service bulletin,” as used in this AD, means the Accomplishment Instructions of Boeing 707 Alert Service Bulletin A3510, dated January 15, 2004.
Within 6 months after the effective date of this AD: Do a detailed inspection for corrosion and cracking of the left and right support ribs of the MLG trunnion. Do the inspection in accordance with all of the actions in Part I of the alert service bulletin. Repeat the inspection thereafter at intervals not to exceed 6 months.
(h) If any corrosion or cracking is found during any inspection required by paragraph (g) of this AD: Before further flight, do all applicable related investigative and corrective actions, and the other specified actions, in accordance with the alert service bulletin; except, where the alert service bulletin specifies to contact Boeing, before further flight, repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative (DER) who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the approval must specifically refer to this AD.
(i) Within 12 months after the effective date of this AD: Do a HFEC inspection for cracking of the left and right support ribs of the MLG trunnion. Do the inspection in accordance with all of the actions in Part II of the alert service bulletin. Repeat the inspection thereafter at intervals not to exceed 12 months.
(j) If cracking is found during any inspection required by paragraph (i) of this AD: Before further flight, repair the cracked area in accordance with a method approved by the Manager, Seattle ACO; or in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the approval must specifically refer to this AD.
