Airworthiness Directive · Amendment 39-16712 · Fuel
The Boeing Company Model 727, 727C, 727-100, 727-100C, 727-200, and 727-200F Series Airplanes
This AD applies to The Boeing Company Model 727, 727C, 727-100, 727-100C, 727-200, and 727-200F series airplanes, all variable numbers, 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 inspections, the operator may not be able to accomplish the inspections 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 (l) 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.
We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires replacing the existing unshielded fuel quantity indication system (FQIS) wire bundles with double shielded FQIS wire bundles, installing a new wire feed-through fitting, and grounding the wire shields, as applicable; and doing repetitive low frequency eddy current (LFEC) inspections for cracking of the fuselage skin, and corrective actions if necessary. This AD also requires revising the maintenance program to incorporate certain airworthiness limitations. This AD was prompted by fuel system reviews conducted by the manufacturer. We are issuing this AD to increase the level of protection from lightning strikes and prevent the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.
Comply with this AD within the compliance times specified, unless already done.
Within 60 months after the effective date of this AD, install double shielded fuel quantity indicating system (FQIS) wire bundles, install a new wire feed-through fitting, and ground the wire shields, as applicable, in accordance with Part 1 of the Accomplishment Instructions of Boeing Service Bulletin 727-28-0131, dated August 18, 2010.
At the applicable times specified in paragraphs (h)(1) or (h)(2) of this AD, do low frequency eddy current (LFEC) inspections for cracking of the fuselage skin, in accordance with Part 2 of the Accomplishment Instructions of Boeing Service Bulletin 727-28-0131, dated August 18, 2010.
(1) For Model 727, 727-100, 727-100C, and 727C series airplanes: Before the accumulation of 45,000 total flight cycles, or within 8,000 flight cycles after the effective date of this AD, whichever occurs later. Repeat the inspections thereafter at intervals not to exceed 8,000 flight cycles.
(2) For Model 727-200 and 727-200F series airplanes: Before the accumulation of 45,000 total flight cycles, or within 16,000 flight cycles after the effective date of this AD, whichever occurs later. Repeat the inspections thereafter at intervals not to exceed 16,000 flight cycles.
(i) If any cracking is found during any inspection required by paragraph (h) of this AD: Before further flight, repair the crack in accordance with a method approved by the Manager, Seattle ACO, FAA. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD. An alternative method of compliance that provides an acceptable level of safety may be used for any repair required by this AD if it is approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO, to make those findings.
Before or concurrently with doing the actions required by paragraph (g) of this AD, or within 30 days after the effective date of this AD, whichever occurs later: Revise the maintenance program by incorporating airworthiness limitations (AWL) No. 28-AWL-18 and 28-AWL-19 in Section D of Section 9 (“AIRWORTHINESS LIMITATIONS-FUEL SYSTEMS”) of the Boeing 727-100/200 Airworthiness Limitations (AWLs) Document, D6-8766-AWL, Revision August 2010. The initial compliance time for AWL No. 28-AWL-18 is within 10 years after the accomplishment of paragraph (g) of this AD, or within 10 years after the effective date of this AD, whichever occurs later.
After accomplishing the action specified in paragraph (j) of this AD, no alternative inspections, inspection intervals, or CDCCLs may be used unless the inspections, intervals, or CDCCLs are approved as an alternative method of compliance in accordance with the procedures specified in paragraph (l) of this AD.
