Discussion
Reports of left engine hydraulic tube assembly failures prompted us to issue AD 2006-02-51, Amendment 39-14459 (71 FR 5581, February 2, 2006). AD 2006-02-51 required repetitive inspection of the hydraulic tube assembly, correction of the symptomatic clamp to hydraulic tube chafing on the left-hand nacelle, and reporting results to the FAA.
After we issued AD 2006-02-51, we continued to receive additional reports of failures of the hydraulic pump outlet tube, including failures on the right engine on certain HBC Model 390 airplanes. This prompted us to supersede AD 2006-02-51 with AD 2006-26-08, Amendment 39-14866 (71 FR 78051, December 28, 2006).
AD 2006-26-08 currently requires you to repetitively inspect the hydraulic pump outlet tube on both engines and immediately replace the tube if damage is found. AD 2006-26-08 also requires you to incorporate an airplane flight manual (AFM) change that limits operation of an engine with its associated firewall hydraulic shutoff valve closed. If an engine is operated with its firewall hydraulic shutoff valve closed, you must replace the hydraulic pump outlet tube.
We issued AD 2006-26-08 as an interim action while we worked with the type certificate holder to develop a design change. We continued to receive additional reports of failures of the hydraulic pump outlet tube.
HBC has now developed kits that incorporate design changes for the hydraulic pump outlet tubes and dampener supports.
Failure of the hydraulic pump outlet tubes, if not prevented, could cause flammable fluid leakage in the engine nacelle. Such leakage could result in a fire. There is also a risk of loss of hydraulic system functions including normal gear extensions, speed brakes, roll spoilers, lift dump, and normal brakes.
Relevant Service Information
We reviewed Hawker Beechcraft Mandatory Service Bulletin No. 29- 3800, issued May 2007. The service information specifies the following actions:
Incorporating Kit No. 390-5804-0001, which replaces the pulse dampener brackets with stiffer brackets and a spacer on both engines; and
Incorporating Kit No. 390-5805-0001, which replaces the hydraulic pump outlet tubes with integral firesleeve hoses.
Raytheon Mandatory Service Bulletin No. SB 29-3771, dated January 2006; and Raytheon Safety Communique No. 267, dated January 2006, will be retained for this AD until both kits referenced above are incorporated.
FAA's Determination and Requirements of This AD
We are issuing this AD because we evaluated all the information and determined the unsafe condition described previously is likely to exist or develop on other products of the same type design. This AD retains the actions of AD 2006-26-08 and requires incorporating Kit No. 390- 5804-0001 and Kit No. 390-5805-0001. Upon incorporating the kits required by this AD, the repetitive inspections and replacement retained from AD 2006-26-08 are no longer necessary. The AFM limitation is still required.
We continue to work with HBC in analyzing the design of the hydraulic system of the Model 390 airplanes. Based on this analysis, we may take future rulemaking action, which could eliminate the need for the current AFM limitation.
In preparing this rule, we contacted type clubs and aircraft operators to get technical information and information on operational and economic impacts. We did not receive any information through these contacts. If received, we would have included a discussion of any information that may have influenced this action in the rulemaking docket.
FAA's Determination of the Effective Date
Since an unsafe condition exists that requires the immediate adoption of this AD, we determined that notice and opportunity for public comment before issuing this AD are impracticable, and that good cause exists for making this amendment effective in fewer than 30 days.
Comments Invited
This AD is a final rule that involves requirements affecting flight safety, and we did not precede it by notice and an opportunity for public comment. We invite you to send any written relevant data, views, or arguments regarding this AD. Send your comments to an address listed under the ADDRESSES section. Include the docket number "FAA-2007-28251; Directorate Identifier 2007-CE-049-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD. We will consider all comments received by the closing date and may amend the AD in light of those comments.
We will post all comments we receive, without change, to http://dms.dot.gov , including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive concerning this AD.
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 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.
Examining the AD Docket
You may examine the AD docket that contains the AD, the regulatory evaluation, any comments received, and other information on the Internet at http://dms.dot.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 647-5227) islocated at the street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.
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 FAA 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 Airworthiness Directive (AD) 2006-26-08, Amendment 39-14866 (71 FR 78051, December 28, 2006), and by adding a new AD to read as follows: