Airworthiness Directive · Amendment 39-14513 · Boeing Model 720 and 720B Series Airplanes
Boeing Model 720 and 720B Series Airplanes
This AD applies to all Boeing Model 720 and 720B series airplanes, certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for all Boeing Model 720 and 720B series airplanes. This AD requires repetitive inspections for any crack, corrosion, or sign of damage (e.g., finish scratches, blistering, or signs of fuel leaking) of the front spar upper chords under the fairing web, and repair if necessary. This AD results from a report that inspections required by a previous AD action are inadequate for Boeing Model 720 and 720B series airplanes. We are issuing this AD to detect and correct any crack, corrosion, or sign of damage of the front spar upper chords under the fairing web, which could result in structural failure of the wing.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 30 days after the effective date of this AD: Do detailed and high-frequency eddy current (HFEC) inspections for any crack, corrosion, or sign of damage (e.g., finish scratches, blistering, or signs of fuel leaking) of the front spar upper chords under the fairing web; and repair if necessary; by accomplishing all the actions specified in Boeing Multi-Operator Message (MOM) 1-151636045-1, dated January 17, 2006. If any crack, corrosion, or sign of damage is found, do all applicable repairs before further flight. Repeat the inspections thereafter at intervals not to exceed 12 months. Where the MOM specifies to contact Boeing for repair instructions: Before further flight, repair using a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the Manager's approval letter must specifically refer to this AD.
Note 1: For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”
Where Boeing MOM 1-151636045-1, dated January 17, 2006, specifies to contact Boeing for appropriate action if it is necessary to oversize fasteners during restoration: Before further flight, oversize the fasteners using a method approved in accordance with a method approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane.
