AD 2008-04-11

This AD becomes effective March 28, 2008.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of March 28, 2008.

For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

Kathrine Rask, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6505; fax (425) 917-6590.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to all Boeing Model 707 airplanes, and Model 720 and 720B series airplanes. That NPRM was published in the Federal Register on July 3, 2007 (72 FR 36370). That NPRM proposed to require 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. That NPRM also proposed to require the initial performance of certain repetitive AWL inspections to phase in those inspections, and repair if necessary.

We provided the public the opportunity to participate in the development of this AD. We have considered the comment received.

For standardization purposes, we have revised this AD in the following ways:

• We have added a new paragraph (i) to this AD to specify that no alternative inspections, inspection intervals, or critical design configuration control limitations (CDCCLs) may be used unless they are part of a later approved revision of Boeing 707/720 Airworthiness Limitations (AWLs) Document D6-7552-AWL, dated March 2006, or unless they are approved as an alternative method of compliance (AMOC). Inclusion of this paragraph in the AD is intended to ensure that the AD-mandated airworthiness limitations changes are treated the same as the airworthiness limitations issued with the original type certificate.

• We have simplified the language in Note 1 of this AD to clarify that an operator must request approval for an AMOC if an operator cannot accomplish the required inspections because an airplane has been previously modified, altered, or repaired in the areas addressed by the required inspections.

Boeing requests that we change the wording in Note 1 of the NPRM as follows:

• Change “new inspections and maintenance actions” to include the words “according to paragraph (g)” after “actions.”

• Change “the operator must request approval for revision to the airworthiness limitations” to “the operator must request approval for deviation from the airworthiness limitations.”

• Remove “as applicable” from the last sentence of the note and change the paragraph reference from “paragraph (g) or (i)” to “paragraph (i).”

Boeing explains that the current wording is difficult to follow.

As stated previously, we have simplified the language in Note 1 of this AD for standardization with other similar ADs. The language the commenter requests we change does not appear in the revised note; therefore, no additional change to this AD is necessary in this regard.

We have added a statement to paragraph (h) of this AD specifying that accomplishment of 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 paragraph (h).

We have carefully reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

There are about 213 airplanes of the affected design in the worldwide fleet. This AD affects about 76 airplanes of U.S. registry. The required actions take about 8 work hours per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the AD for U.S. operators is $48,640, or $640 per airplane.

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866;

(2) Is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

(3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

2. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):