Federal Register: April 7, 2009 (Volume 74, Number 65)
DOCID: fr07ap09-11 FR Doc E9-7805
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
CFR Citation: 14 CFR Part 39
Docket ID: [Docket No. FAA-2009-0314; Directorate Identifier 2008-NM-196-AD]
RIN ID: RIN 2120-AA64
NOTICE: PROPOSED RULES
DOCID: fr07ap09-11
ACTION: Airworthiness Directives:
DOCUMENT ACTION: Notice of proposed rulemaking (NPRM).
SUBJECT CATEGORY:
Airworthiness Directives; Boeing Model 767-200, -300, -300F, and -400ER Series Airplanes
DATES: We must receive comments on this proposed AD by May 22, 2009.
DOCUMENT SUMMARY:
We propose to adopt a new airworthiness directive (AD) for certain Boeing Model 767200, 300, 300F, and 400ER series airplanes. This proposed AD would require an inspection to determine if certain motor operated valve actuators for the fuel tanks are installed, and related investigative and corrective actions if necessary. This proposed AD results from fuel system reviews conducted by the manufacturer. We are proposing this AD to prevent an ignition source inside the fuel tanks, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.
SUMMARY:
Boeing Model 767–200 Series Airplanes, et al.,
SUPPLEMENTAL INFORMATION
Comments Invited
We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include ``Docket No. FAA20090314; Directorate Identifier 2008NM196AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.
We will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.
Discussion
The FAA has examined the underlying safety issues involved in fuel
tank explosions on several large transport airplanes, including the
adequacy of existing regulations, the service history of airplanes
subject to those regulations, and existing maintenance practices for
fuel tank systems. As a result of those findings, we issued a
regulation titled ``Transport Airplane Fuel Tank System Design Review,
Flammability Reduction and Maintenance and Inspection Requirements''
(66 FR 23086, May 7, 2001). In addition to new airworthiness standards for transport airplanes and
[[Page 15682]]
new maintenance requirements, this rule included Special Federal
Aviation Regulation No. 88 (``SFAR 88,'' Amendment 2178, and subsequent Amendments 2182 and 2183).
Among other actions, SFAR 88 requires certain type design (i.e., type certificate (TC) and supplemental type certificate (STC)) holders to substantiate that their fuel tank systems can prevent ignition sources in the fuel tanks. This requirement applies to type design holders for large turbinepowered transport airplanes and for subsequent modifications to those airplanes. It requires them to perform design reviews and to develop design changes and maintenance procedures if their designs do not meet the new fuel tank safety standards. As explained in the preamble to the rule, we intended to adopt airworthiness directives to mandate any changes found necessary to address unsafe conditions identified as a result of these reviews.
In evaluating these design reviews, we have established four criteria intended to define the unsafe conditions associated with fuel tank systems that require corrective actions. The percentage of operating time during which fuel tanks are exposed to flammable conditions is one of these criteria. The other three criteria address the failure types under evaluation: Single failures, single failures in combination with a latent condition(s), and inservice failure experience. For all four criteria, the evaluations included consideration of previous actions taken that may mitigate the need for further action.
We have determined that the actions identified in this AD are necessary to reduce 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.
Boeing has found that, under specific conditions, it is possible for electrical current to flow through certain motor operated valve (MOV) actuators into the fuel tank. Boeing has developed a new valve actuator to replace those actuators. The new MOV actuator includes an internal electrical isolator to give the MOV actuator protection against electrical energy from lightning, hot shorts, and internal shorts. The new MOV actuator will prevent the flow of an electrical current into the fuel tank, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.
Related Rulemaking
On May 8, 2008, we issued AD 20081101, amendment 3915523 (73 FR 29414, May 21, 2008), for certain Boeing Model 767200, 300, 300F, and 400ER series airplanes. That AD requires revising the FAAapproved maintenance program to incorporate new airworthiness limitations (AWLs) for fuel tank systems to satisfy SFAR 88 requirements. That AD also requires the initial inspection of certain repetitive AWL inspections to phase in those inspections, and repair if necessary. That AD resulted from a design review of the fuel tank systems. We issued that 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 explosion and consequent loss of the airplane.
The version of the Maintenance Planning Data (MPD) Document (described below) that is required by AD 20081101 and referenced in this proposed AD has not been changed and includes the AWLs for this proposed AD.
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin 76728A0090, dated July 3, 2008. The service bulletin describes procedures for inspecting to determine the part number (P/N) of MOV actuators for the main and center fuel tanks. The service bulletin specifies that no more work is necessary if the part number is acceptable.
If the part number is not acceptable, the service bulletin specifies related investigative and corrective actions as follows:
Boeing Alert Service Bulletin 76728A0090, dated July 3, 2008, also cites Section 9 of the Boeing 767 MPD Document, D622T0019.
FAA's Determination and Requirements of This Proposed AD
We are proposing this AD because we evaluated all relevant
information and determined the unsafe condition described previously is
likely to exist or develop in other products of the(se) same type
design(s). This proposed AD would require accomplishing the actions
specified in the service information described previously, except as
discussed under ``Differences Between the Proposed AD and the Service Bulletin.''
Differences Between the Proposed AD and the Service Bulletin
Although Boeing Alert Service Bulletin 76728A0090, dated July 3, 2008 (``the service bulletin''), refers to Section 9 of the Boeing 767 Maintenance Planning Data (MPD) Document, D622T0019, this proposed AD would not require revising the FAAapproved maintenance program to incorporate the new airworthiness limitations (AWLs) in Revision April 2008 of that document. We require that action in AD 20081101.
The service bulletin also specifies replacing any MOV actuator
having part number MA20A10011 with a new MOV actuator having P/N
MA30A1001; however, this proposed AD would include other acceptable
replacement part numbers. Other approved part numbers that are interchangeable with P/N MA30A1001 are as follows:
Costs of Compliance
We estimate that this proposed AD would affect 397 airplanes of U.S. registry. We also estimate that it would take about 1 workhour per product to comply with this proposed AD. The average labor rate is $80 per workhour. Required parts would cost about $80 per product. Based on these figures, we estimate the cost of this proposed AD to the U.S. operators to be $63,520, or $160 per product.
Authority for This Rulemaking
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 [[Page 15683]]
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.
Regulatory Findings
We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 this proposed regulation:
1. Is not a ``significant regulatory action'' under Executive Order 12866,
2. Is not a ``significant rule'' under the 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.
You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows: PART 39AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by adding the following new AD:
Boeing: Docket No. FAA20090314; Directorate Identifier 2008NM 196AD.
Comments Due Date
(a) We must receive comments by May 22, 2009.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 767200, 300, 300F, and
400ER series airplanes, certificated in any category; as identified
in Boeing Alert Service Bulletin 76728A0090, dated July 3, 2008. Unsafe Condition
(d) This AD results from fuel system reviews conducted by the
manufacturer. We are issuing this AD to prevent an ignition source
inside the fuel tanks, which, in combination with flammable fuel
vapors, could result in a fuel tank explosion and consequent loss of the airplane.
Compliance
(e) Comply with this AD within the compliance times specified, unless already done.
Subject
(f) Air Transport Association (ATA) of America Code 28: Fuel. Inspection and Related Investigative/Corrective Actions
(g) Within 60 months after the effective date of this AD, do the actions in paragraphs (g)(1) and (g)(2) of this AD.
(1) Inspect the motor operated valves (MOVs) in the main and
center fuel tanks to determine if any MOV having part number (P/N)
MA20A10011 is installed, in accordance with the Accomplishment
Instructions of Boeing Alert Service Bulletin 76728A0090, dated
July 3, 2008. A review of airplane maintenance records is acceptable
in lieu of this inspection if the part number can be conclusively determined from that review.
(2) Do all applicable related investigative and corrective
actions specified in and in accordance with the Accomplishment
Instructions of Boeing Alert Service Bulletin 76728A0090, dated
July 3, 2008, except as provided by paragraph (h) of this AD. Alternative Part Numbers
(h) Where Boeing Alert Service Bulletin 76728A0090, dated July
3, 2008, specifies replacing any actuator having P/N MA20A10011
with a new actuator having P/N MA30A1001, a new or serviceable
actuator having any of the following part numbers is also acceptable as a replacement part: MA20A2027 (S343T00356); MA11A12651
(S343T00341); or AV311 (S343T003111).
Alternative Methods of Compliance (AMOCs)
(i)(1) The Manager, Seattle Aircraft Certification Office (ACO),
FAA, has the authority to approve AMOCs for this AD, if requested
using the procedures found in 14 CFR 39.19. Send information to
FOR FURTHER INFORMATION CONTACT
Douglas Bryant, Aerospace Engineer, Propulsion Branch, ANM140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 980573356; telephone (425) 9176505; fax (425) 9176590.