The FAA proposed to amend 14 CFR part 39 by superseding AD 99-02-51, Amendment 39-11108 (64 FR 16339, April 5, 1999), with a proposed AD. The proposed AD applies to RRC AE 3007A and AE 3007C series turbofan engines. We published the proposed AD in the Federal Register on March 29, 2007 (72 FR 14724). That action proposed to:
Prohibit before further flight, any flight following a ground engine start where the engine oil temperature is below 32 [deg]F (0 [deg]C), unless certain preflight operational procedures are followed to ensure that there is no excessive loss of oil from leakage at the air turbine starter shaft; and
Require terminating action to the prohibition requirements of the existing AD, by removing from service certain seal P/Ns from the accessory gearbox air turbine starter mounting pad and installing an improved seal; and
Require removing certain P/N drain caps, drain adapters, and orifice inserts, and installing an open adapter onthe starter pad drain.
Examining the AD Docket
You may examine the AD docket on the Internet at http:// www.regulations.gov; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.
Comments
We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.
Request To Continue To Allow Existing Approved AMOCs
Four commenters, ExpressJet Inc., RRC, Embraer, and Cessna Aircraft Company state that alternative methods of compliance (AMOCs) currently approved for AD 99-02-51 should be allowed while this AD is not incorporated or until September 30, 2009. Paragraph (l) of the proposed rule states that AMOCs approved for AD 99-02-51 are not approved for the new rule. Until all engines are modified as required by paragraph (g) of the proposed rule, an aircraft may encounter 32 [deg]F temperature or lower and it seems arbitrary to disallow the use of data that has already been approved and in use for over two years. Operators would have the burden of requesting the same AMOC for the superseding AD. Allowing the currently approved AMOCs would bridge the time gap to the Terminating Action compliance date.
We agree. We changed Alternative Methods of Compliance (AMOC), paragraph (l) from "AMOCs approved for AD 99-02-51 are not approved as AMOCs for this AD.'' to "AMOCs currently approved for AD 99-02-51 will remain in effect until the terminating action date for this AD, September 30, 2009. After that date, these AMOCs will expire and not be approved as AMOCs for this AD.'' This change will avoid confusion in the field and the AMOCs are stillappropriate for the period before the mandatory terminating action date. These AMOCs will expire permanently on September 30, 2009, after which the only allowable configuration option is the new seal, a compatible starter and an open seal drain.
Request To Provide a More Accurate Description of the Original Problem
Two commenters, RRC and Embraer, ask us to include a more accurate description of the original problem. They state that the nomenclature "Starter shaft seal'' may cause confusion with the seal of the pneumatic Air Turbine Starter (ATS). We agree. We changed Unsafe Condition, paragraph (d) from "* * * due to loss of engine oil from the starter shaft seal'' to "* * * due to loss of engine oil from the engine accessory gearbox starter pad shaft seal drain and possible loss of the airplane.''
Request To Clarify the Regulatory Text
Rolls-Royce Corporation asks us to make the following changes for clarity:
Prohibited Flights, paragraph (f)(2): Change "Oil consumption greater than 0.32 quart per hour (303 cc per hour) * * *'' to "Oil consumption greater than 0.32 quart per hour, or 300 cc per hour, * * *'' Although it may not be a completely accurate quart-to-cc conversion, 300 cc is the value listed in all RRC manuals.
Terminating Action, paragraph (g): Change "* * * do the following, as applicable to your engine model and configuration.'' to "* * * do the following, as applicable to your configuration.'' Engine model applicability is already established so it can be deleted here to make a simpler statement.
Terminating Action, paragraph (g)(1): Change "Remove seal part number (P/N) * * * '' to "Remove seal and related component part numbers (P/Ns) * * *'' The P/Ns listed are not only currently approved seals but also adjacent hardware including a wave spring and spacer used in one of the approved configurations. This change accounts for all current hardware, not just the seals.
Terminating Action, paragraph (g)(2): Change "Install a new seal, P/N AS3209-026 * * *'' to "Install a new O-ring, P/N AS3209- 026 or M83248/1-026* * *'' RRC lists both of these P/Ns as acceptable alternatives in the engine parts list. Also, the correct nomenclature is O-ring, not seal.
Prohibition of Seals, paragraph (i): Change "Once the terminating action in this AD is performed on an engine, seal P/Ns * *
*'' to "Once the terminating action in this AD is performed on an
engine, seal and related component P/Ns * * *'' This change accounts for all current hardware, not just the seals.
We agree with the suggestions and incorporated them into the applicable regulatory text of the AD.
Request to Not Implement the AD
Rolls-Royce North America, Inc., c/o American Eagle Airlines, asks us to not implement the AD, or at least extend the required completion date for the terminating action by at least 6-12 months. They believe that many AE3007A and AE3007C engines are not yet compliant with RRC Service Bulletin AE 3007A-72-321 and or SB AE 3007A-72-330. They state that it would be too much of a burden to modify all of the engines currently out in the field to be compliant with the proposed AD by September 30, 2009. A drastic maintenance campaign such as this would adversely affect the AE3007A and C fleet both in terms of costs and operations to drastic proportions.
We don't agree. We have determined that we can better assure long- term continued operational safety by design changes that remove the source of the problem, rather than by repetitive inspections or other special procedures. Based on the availability of the required parts and the support from the vast majority of operators and their ability to comply within the original specified date, we believe this is a reasonable time period and will maintain the final compliance date of September 30, 2009.
Conclusion
We have carefully reviewed the available data, including the comments 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.
Costs of Compliance
We estimate that this AD will affect 1,868 RRC AE 3007A and AE 3007C series turbofan engines installed on aircraft of U.S. registry. We also estimate that it will take about 4 work-hours per engine to perform the proposed terminating action, and that the average labor rate is $80 per work-hour. Required parts will cost about $2,917 per engine. Based on these figures, if all engines incorporated the terminating action, we estimate the total cost of this AD to U.S. operators to be $6,046,100.
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 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 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 summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary at the address listed under ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS 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 removing Amendment 39-11108 64 FR 16339 April 5, 1999, and by adding a new airworthiness directive, Amendment 39-15271, to read as follows: