Airworthiness Directive · Amendment 39-15383 · Boeing Model 707 Airplanes, and Model 720 and 720B Series Airplanes
Boeing Model 707 Airplanes, and Model 720 and 720B Series Airplanes
Superseded. A later AD replaced this one: AD 2008-04-11 R1. Comply with the one in force.
This AD applies to all Boeing Model 707-100 long body, -200, -100B long body, and -100B short body series airplanes; Model 707-300, -300B, -300C, and -400 series airplanes; and Model 720 and 720B series airplanes; certificated in any category.
Note 1: This AD requires revisions to certain operator maintenance documents to include new inspections. Compliance with these inspections is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by these limitations, the operator may not be able to accomplish the actions described in the revisions. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval for an alternative method of compliance according to paragraph (i) of this AD. The request should include a description of changes to the required inspections that will ensure the continued operational safety of the airplane.
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 revising the FAA-approved maintenance program by incorporating new airworthiness limitations (AWLs) for fuel tank systems to satisfy Special Federal Aviation Regulation No. 88 requirements. This AD also requires the initial performance of certain repetitive AWL inspections to phase in those inspections, and repair if necessary. This AD results from a design review of the fuel tank systems. We are issuing this AD to prevent the potential for ignition sources inside fuel tanks caused by latent failures, alterations, repairs, or maintenance actions, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss 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.
The term “D6-7552-AWL March 2006,” as used in this AD, means Boeing 707/720 Airworthiness Limitations (AWLs) Document D6-7552-AWL, dated March 2006.
Before December 16, 2008, revise the FAA-approved maintenance program by incorporating the information in the sections specified in paragraphs (g)(1) through (g)(3) of this AD, except that the initial inspection specified in paragraph (h) of this AD must be done at the time specified in paragraph (h). Accomplishing the revision in accordance with a later revision of D6-7552-AWL March 2006 is an acceptable method of compliance if the revision is approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA.
(1) Section B., “FUEL SYSTEMS AIRWORTHINESS LIMITATIONS,” of D6-7552-AWL March 2006.
(2) Section C., “SYSTEM AWL PAGE FORMAT,” of D6-7552-AWL March 2006.
(3) Section D., “AIRWORTHINESS LIMITATIONS—FUEL SYSTEMS,” of D6-7552-AWL March 2006.
At the later of the times specified in paragraphs (h)(1) and (h)(2) of this AD: Do a detailed inspection of external wires over the center fuel tank for damaged or loose clamps, wire chafing, and wire bundles in contact with the surface of the center fuel tank, in accordance with Section D, “AIRWORTHINESS LIMITATIONS—FUEL SYSTEMS,” AWL 28-AWL-01, of D6-7552-AWL March 2006. If any discrepancy is found during this inspection, repair the discrepancy before further flight in accordance with D6-7552-AWL March 2006. Accomplishing the actions required by this paragraph in accordance with a later revision of D6-7552-AWL March 2006 is an acceptable method of compliance if the revision is approved by the Manager, Seattle ACO. Accomplishing AWL 28-AWL-01 as part of an FAA-approved maintenance program prior to the later of the times specified in paragraphs (h)(1) and (h)(2) of this AD constitutes compliance with the requirements of this paragraph.
(1) Before the accumulation of 36,000 total flight cycles, or within 120 months since the date of issuance of the original standard airworthiness certificate or the date of issuance of the original export certificate of airworthiness, whichever occurs first.
(2) Within 72 months after the effective date of this AD.
Note 2: 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.”
(i) After accomplishing the actions specified in paragraphs (g) and (h) of this AD, no alternative inspections, inspection intervals, or CDCCLs may be used unless the inspections, intervals, or CDCCLs are part of a later revision of D6-7552-AWL March 2006, that is approved by the Manager, Seattle ACO; or unless the inspections, intervals, or CDCCLs are approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (j) of this AD.
