[Federal Register Volume 69, Number 140 (Thursday, July 22, 2004)]
[Proposed Rules]
[Pages 43783-43785]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-16684]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-18660; Directorate Identifier 2003-NM-161-AD]
RIN 2120-AA64


Airworthiness Directives; Raytheon (Beech) Model MU-300-10, 400, 
400A, and 400T Series Airplanes; and Raytheon (Mitsubishi) Model Beech 
MU-300 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt 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 proposed AD would 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

[[Page 43784]]

if necessary. This proposed 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 proposing 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.

DATES: We must receive comments on this proposed AD by September 7, 
2004.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     By fax: (202) 493-2251.
     Hand Delivery: room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays. For service 
information identified in this proposed AD, contact Raytheon Aircraft 
Company, Department 62, P.O. Box 85, Wichita, Kansas 67201-0085.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or at the Docket Management Facility, U.S. 
Department of Transportation, 400 Seventh Street SW., room PL-401, on 
the plaza level of the Nassif Building, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Jeff Pretz, Aerospace Engineer, 
Airframe Branch, ACE-118W, FAA, Wichita Aircraft Certification Office, 
1801 Airport Road, Propulsion 100, Mid-Continent Airport, Wichita, 
Kansas 67209; telephone (316) 946-4153; fax (316) 946-4107.

SUPPLEMENTARY INFORMATION: 

Docket Management System (DMS)

    The FAA has implemented new procedures for maintaining AD dockets 
electronically. As of May 17, 2004, new AD actions are posted on DMS 
and assigned a docket number. We track each action and assign a 
corresponding directorate identifier. The DMS AD docket number is in 
the form ``Docket No. FAA-2004-99999.'' The Transport Airplane 
Directorate identifier is in the form ``Directorate Identifier 2004-NM-
999-AD.'' Each DMS AD docket also lists the directorate identifier 
(``Old Docket Number'') as a cross-reference for searching purposes.

Comments Invited

    We invite you to submit any written relevant data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2004-18660; 
Directorate Identifier 2003-NM-161-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments submitted by the closing date and may amend the 
proposed 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 with FAA 
personnel concerning this proposed AD. Using the search function of 
that website, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You can review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
can visit http://dms.dot.gov.
    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications that affect you. You can get more information about 
plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the Docket

    You can examine the AD docket in person at the Docket Management 
Facility office between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The Docket Management Facility office 
(telephone (800) 647-5227) is located on the plaza level of the Nassif 
Building at the DOT street address stated in the ADDRESSES section. 
Comments will be available in the AD docket shortly after the DMS 
receives them.

Discussion

    We have received a report indicating that fuel leaked from 
components in the spoiler mixer bay of several Raytheon (Beech) Model 
400A series airplanes. On one occasion, fuel migrated into the aft 
fuselage, resulting in fuel odor in the aft baggage compartment. 
Further investigation by the manufacturer showed that both the left and 
right spoiler bay mixer panels of certain Raytheon airplane models 
lacked the drain holes required by the type design. If there is a fuel 
leak, and the mixer panels do not have the requisite drain holes, fuel 
could pool in the spoiler mixer bay. Fuel could also migrate from the 
mixer bay into the aft fuselage if the sealant is missing from the 
bulkhead between the mixer bay and the aft fuselage compartment. This 
condition, if not corrected, could result in 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.
    Raytheon (Beech) Model 400 and 400T series airplanes, and Raytheon 
(Beech) Model MU-300 airplanes, are similar in design to the Raytheon 
(Beech) Model 400A series airplanes that had the fuel leaks. Therefore, 
all of these airplanes could have the same unsafe condition, and all 
are subject to the requirements of this proposed AD.

Relevant Service Information

    We have reviewed Raytheon Service Bulletin SB 53-3486, dated June 
2003. The service bulletin describes procedures for a one-time 
inspection of the spoiler mixer bay panels to determine if there are 
the correct number of drain holes; and a one-time inspection for 
discrepancies of the sealant on the relief cutout on the aft pressure 
bulkhead, and the baffles at left butt line (BL) 19.13 and right BL 
10.43; and corrective actions, if necessary. Discrepancies include 
missing sealant, or inadequate sealant, which is defined as sealant not 
adhering properly, flaking, peeling, or having voids, gaps, or 
pinholes. The service bulletin also describes procedures for corrective 
actions. The corrective actions include drilling at least one new drain 
hole, and any additional drain holes needed to make a total of five at 
specified places in each mixer bay panel; and applying sealant, if 
necessary, to repair discrepancies. We have determined that 
accomplishing the actions specified in the service bulletin will 
adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. Therefore, we are proposing this AD, which 
would require a one-time inspection of the spoiler

[[Page 43785]]

mixer bay panels to determine if there are the correct number of drain 
holes; and a one-time inspection of the sealant on the relief cutout on 
the aft pressure bulkhead, and the baffles at left butt line (BL) 19.13 
and right BL 10.43 for discrepancies; and corrective actions, if 
necessary. The proposed AD would require you to use the service 
information described previously to perform these actions.

Clarification of Inspection Language

    Although the service bulletin does not define the type of 
inspection required for the drain holes and the sealant, this proposed 
AD would classify the inspection as a ``general visual inspection.'' 
Note 1 of this proposed AD defines this inspection.

Costs of Compliance

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

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

    We have 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 that the 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed 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, 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 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 adding the following new 
airworthiness directive (AD):

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

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by September 7, 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 (a)(1) and (a)(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 (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.

    Issued in Renton, Washington, on July 9, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-16684 Filed 7-21-04; 8:45 am]
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