AD 2004-22-02

The FAA is adopting a new airworthiness directive (AD) for certain Raytheon (Beech) Model MU-300-10, 400, 400A, and 400T series airplanes; and certain Raytheon (Mitsubishi) Model Beech MU-300 airplanes. This AD requires a one-time inspection of certain panels in the spoiler mixer bay for the presence of drain holes, and the addition of at least one new drain hole; and a one-time inspection for discrepancies of the sealant on the relief cutout on the aft pressure bulkhead, and on certain baffles; and corrective actions if necessary. This AD is prompted by a report of fuel leaking from components in the spoiler mixer bay of several Raytheon (Beech) Model 400A series airplanes. We are issuing this AD to prevent the accumulation of fuel and/or fuel vapor in the spoiler mixer bay and/or the aft fuselage compartment, which could result in a fire in the airplane.

Final rule.

2004-22-02 Raytheon Aircraft Company (Formerly Beech): Amendment 39- 13830. Docket No. FAA-2004-18660; Directorate Identifier 2003-NM- 161-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective December 1, 2004.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Raytheon (Beech) Model MU-300-10, 400, 400A, and 400T series airplanes; and Raytheon (Mitsubishi) Model Beech MU-300 airplanes; certificated in any category; as listed in Raytheon Service Bulletin SB 53-3486, dated June, 2003.

Unsafe Condition

(d) This AD was prompted by a report of fuel leaking from components in the spoiler mixer bay of several Raytheon (Beech) Model 400A series airplanes. We are issuing this AD to prevent the accumulation of fuel and/or fuel vapor in the spoiler mixer bay and/ or the aft fuselage compartment, which could result in a fire in the airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Inspections and Corrective Actions

(f) Within 400 flight hours or 12 months after the effective date of this AD, whichever occurs first, do the actions in paragraphs (f)(1) and (f)(2) of this AD. Do all actions in accordance with the Accomplishment Instructions of Raytheon Service Bulletin SB 53-3486, dated June 2003.

(1) Do a one-time general visual inspection of the spoiler mixer bay panels to determine the presence of drain holes. Before further flight after doing this inspection, drill at least one new drain hole, and any additional drain holes needed to make a total of five, at the places in each mixer bay panel specified in the service bulletin.

(2) Do a one-time general visual inspection for discrepancies of the sealant on the relief cutout on the aft pressure bulkhead, and of the small triangular-shaped baffles at left butt line (BL) 19.13 and right BL 10.43. Before further flight after doing this inspection, do any applicable corrective actions.

Note 1: For the purposes of this AD, a general visual inspection is: "A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked."

Parts Installation

(g) As of the effective date of this AD, no person may install on any airplane a spoiler mixer bay panel that has a part number listed in paragraph 3.B., "Spares," of the Accomplishment Instructions of Raytheon Service Bulletin SB 53-3486, dated June 2003, unless the panel has been inspected and modified in accordance with paragraph (f)(1) of this AD.

Alternative Methods of Compliance (AMOCs)

(h) The Manager, Wichita Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

Material Incorporated by Reference

(i) You must use Raytheon Service Bulletin SB 53-3486, dated June 2003, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approves the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. For copies of the service information, contact Raytheon Aircraft Company, Department 62, P.O. Box 85, Wichita, Kansas 67201-0085. For information on the availability of this material at the National Archives and Records Administration (NARA), call (202) 741-6030, or goto
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. You may view the AD docket at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW, room PL-401, Nassif Building, Washington, DC.

The FAA proposed to amend 14 CFR Part 39 with an AD for certain Raytheon (Beech) Model MU-300-10, 400, 400A, and 400T series airplanes; and certain Raytheon (Mitsubishi) Model Beech MU-300 airplanes. The proposed AD was published in the Federal Register on July 22, 2004 (69 FR 43783), to require a one-time inspection of certain panels in the spoiler mixer bay for the presence of drain holes, and the addition of at least one new drain hole; and a one-time inspection for discrepancies of the sealant on the relief cutout on the aft pressure bulkhead, and on certain baffles; and corrective actions if necessary.

Comments

We provided the public the opportunity to participate in the development of this AD. No comments have been submitted on the proposed AD or on the determination of the cost to the public.

Conclusion

We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed.

Clarification of Requirements in Paragraph (f) of the Final Rule

In paragraph (f) of the proposed AD we inadvertently referenced paragraphs (a)(1) and (a)(2) of the proposed AD; this is a typographical error. It was our intent to reference paragraphs (f)(1) and (f)(2). Paragraph (a) only references the comment due date and does not contain subparagraphs (1) and (2). Paragraph (f) of this final rule has been changed to correctly reference paragraphs (f)(1) and (f)(2) of this AD.

Costs of Compliance

This AD will affect about 673 airplanes worldwide. The following table provides the estimated costs for U.S. operators to comply with this AD.

Estimated Costs

Action
Work hours
Average labor rate per hour
Parts
Cost per airplane
Number of U.S. registered airplanes
Fleet cost
Inspections
1
$65
None
$65
610
$39,650
Drilling one drain hole
3
65
None
195
610
$118,950

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 regulatory evaluation of the estimated costs to comply with this AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

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.

39.13 [Amended]

2. The FAA amends 39.13 by adding the following new airworthiness directive: