Document ID: FAA-2008-0842-0003
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Bombardier-Rotax GmbH 914 F Series Reciprocating Engines
Posted Date: 2008-12-22T05:00Z

[Federal Register: December 22, 2008 (Volume 73, Number 246)]
[Rules and Regulations]
[Page 78173-78175]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr22de08-7]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0842; Directorate Identifier 2008-NE-24-AD;
Amendment 39-15771; AD 2008-26-05]
RIN 2120-AA64

Airworthiness Directives; Bombardier-Rotax GmbH 914 F Series
Reciprocating Engines

AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the
products listed above. This AD results from mandatory continuing
airworthiness information (MCAI) issued by an aviation authority of
another country to identify and correct an unsafe condition on an
aviation product. The MCAI describes the unsafe condition as:

    Occurrence of cracks in the exhaust muffler in the area of the
exhaust bottom and exhaust flange were reported, which could lead to
toxic contamination inside the cabin.

    We are issuing this AD to require actions to correct the unsafe
condition on these products, which could result in carbon monoxide
contamination in the cockpit, which can adversely affect the pilot, and
possibly result in loss of control of the aircraft.

DATES: This AD becomes effective January 26, 2009.

ADDRESSES: The Docket Operations office is located at Docket Management
Facility, U.S. Department of Transportation, 1200 New Jersey Avenue,
SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-
0001.

FOR FURTHER INFORMATION CONTACT: Richard Woldan, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park; Burlington, MA 01803; e-mail:
Richard.woldan@faa.gov; telephone (781) 238-7136; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 to include an AD that would apply to the specified products.
That NPRM was published in the Federal Register on September 12, 2008
(73 FR 52932). That NPRM proposed to correct an unsafe condition for
the specified products. The MCAI states that:

    Occurrence of cracks in the exhaust muffler in the area of the
exhaust bottom and exhaust flange were reported, which could lead to
toxic contamination inside the cabin.

Comments

    We gave the public the opportunity to participate in developing
this AD. We considered the comments received.

Suggestion To Pressurize the Muffler With Air To Detect Leaks

    One commenter, a private citizen, suggests that we change the
proposed AD to inspect for cracks by pressurizing the muffler with air
and using a soap solution to detect leaks. The commenter states that
this method would detect finer cracks than just a visual inspection
would find.
    We partially agree. The suggested inspection is likely more
sensitive, but the visual inspections specified in the

[[Page 78174]]

proposed AD are sensitive enough to detect an exhaust leak that could
create an unsafe condition. However, operators can request approval to
use another inspection method instead of using the method specified in
the AD, by requesting approval of an alternative method of compliance
(AMOC). We did not change the AD.

Request To Allow Repair of a Cracked Muffler

    The same commenter requests that we change the proposed AD to allow
the repair of a cracked muffler instead of replacing the muffler. The
commenter infers that this would be more cost effective.
    We disagree. The cracks occurring in the mufflers are in weld areas
that were part of the original manufacturing process. The muffler
manufacturing process was changed to correct the cracking problem. A
repair in the area of the original weld might not correct the unsafe
condition and could make the muffler more susceptible to future
cracking, thereby requiring continued inspections. However, operators
can request approval of an AMOC for a muffler repair method, but
operators would have to address the repair concerns mentioned
previously. We did not change the AD.

Suggestion To Install a Carbon Monoxide (CO) Detector in the Cockpit

    The same commenter suggests that operators install a CO detector in
the cockpit to identify presence of harmful levels of CO. The commenter
infers that this would provide an additional level of protection.
    We disagree. The inspections specified in the proposed AD are
adequate to detect an exhaust leak that could create an unsafe
condition. Also, maintenance checks of the CO detector would be
required to ensure its correct operation, if it was being relied on as
a method to prevent the unsafe condition. We did not change the AD.

Conclusion

    We reviewed the available data, including the comments received,
and determined that air safety and the public interest require adopting
the AD as proposed.

Costs of Compliance

    Based on the service information, we estimate that this AD will
affect about 75 products of U.S. registry. We also estimate that it
will take about 2 work-hours per product to comply with this AD. The
average labor rate is $80 per work-hour. Required parts will cost about
$1,674 per product. Based on these figures, we estimate the cost of the
AD on U.S. operators to be $137,550. Our cost estimate is exclusive of
possible warranty coverage.

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 this AD:
    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 AD and placed it in the AD docket.

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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator,
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2008-26-05 Bombardier-Rotax GmbH: (Formerly Rotax GmbH): Amendment
39-15771. Docket No. FAA-2008-0842; Directorate Identifier 2008-NE-
24-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective January
26, 2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier-Rotax GmbH 914 F series
reciprocating engines with engine exhaust muffler, part number (P/N)
979402 or 979404, with serial numbers (SNs) listed in Table 1 of
this AD, installed. These engines are installed on, but not limited
to, Aeromot-Industria Mecanico Metalurgica, AMT-300 (Turbo Ximango
Shark), Diamond Aircraft Industries, HK 36 TTS, HK 36 TTC, HK 36
TTC-ECO, and Stemme GmbH & Co. KG, S10-VT series powered sailplanes.

[[Page 78175]]

        Table 1--Affected Exhaust Mufflers by Group, P/N, and SN
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           Group                   P/N                    SN
------------------------------------------------------------------------
(1) A......................          979402  02.0001 through 02.0322,
                                              03.0002, 03.0005, 03.0011,
                                              03.0015, 03.0017, 03.0028,
                                              03.0029, 03.0037, 03.0038,
                                              03.0040, 03.0050, 03.0069,
                                              03.0072, 03.0073, 03.0078,
                                              03.0080 through 03.0086,
                                              03.0088 through 03.0090,
                                              03.0092 through 03.0101,
                                              03.0103, and 03.0108.
(2) B......................          979402  03.0001, 03.0003, 03.0004,
                                              03.0006, 03.0007 through
                                              03.0010, 03.0012 through
                                              03.0014, 03.0016, 03.0018
                                              through 03.0027, 03.0030
                                              through 03.0036, 03.0039,
                                              03.0041 through 03.0049,
                                              03.0051 through 03.0068,
                                              03.0070, 03.0071, 03.0074
                                              through 03.0077, 03.0079,
                                              03.0087, 03.0091, 03.0102,
                                              and 03.0104 through
                                              03.0107.
                                     979404  03.0200 through 04.0799.
------------------------------------------------------------------------

Reason

    (d) Occurrence of cracks in the exhaust muffler in the area of
the exhaust bottom and exhaust flange were reported, which could
lead to toxic contamination inside the cabin.

    We are issuing this AD to prevent carbon monoxide contamination
in the cockpit, which can adversely affect the pilot, and possibly
result in loss of control of the aircraft.

Actions and 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.

Initial Visual Inspection

Group A Exhaust Mufflers

    (f) For exhaust mufflers specified in Group A of Table 1 of this
AD, within 50 hours of operation after the effective date of this
AD, do the following:
    (1) Perform a visual inspection around the fillet weld of the
exhaust inlet flange and around the weld of the exhaust outlet for
evidence of leakage or cracks. Information on inspecting the exhaust
muffler can be found in Bombardier-Rotax GmbH 914 F Service Bulletin
(SB) No. SB-914-028 R1, dated November 8, 2004.
    (2) If you see evidence of an exhaust leak or cracks, replace
the exhaust muffler.

Group B Exhaust Mufflers

    (g) For exhaust mufflers specified in Group B of Table 1 of this
AD, within 50 hours of operation after the effective date of this
AD, do the following:
    (1) Perform a visual inspection around the weld of the exhaust
outlet for evidence of leakage or cracks. Information on inspecting
the exhaust muffler can be found in Bombardier-Rotax GmbH 914 F
Service Bulletin No. SB-914-028 R1, dated November 8, 2004.
    (2) If you see evidence of an exhaust leak or cracks, replace
the exhaust muffler.

Repetitive Visual Inspections

    (h) Within 50 hours of operation since the last inspection,
perform the actions specified in paragraphs (f)(1) through (f)(2)
and (g)(1) through (g)(2) of this AD.

FAA AD Differences

    (i) None.

Alternative Methods of Compliance (AMOCs)

    (j) The Manager, Engine Certification Office, FAA, has the
authority to approve AMOCs for this AD, if requested using the
procedures found in 14 CFR 39.19.

Related Information

    (k) Refer to MCAI EASA Airworthiness Directive 2006-0127, dated
May 18, 2006, and Bombardier-Rotax GmbH 914 F Service Bulletin No.
SB-914-028 R1, dated November 8, 2004, for related information.
Contact Bombardier-Rotax GmbH, Gunskirchen, Austria; telephone:
7246-601-423; fax: 7246-601-760, or go to: http://www.rotax-
aircraft-engines.com, for a copy of this service bulletin.
    (l) Contact Richard Woldan, Aerospace Engineer, Engine
Certification Office, FAA, Engine and Propeller Directorate, 12 New
England Executive Park; Burlington, MA 01803; telephone (781) 238-
7136; fax (781) 238-7199, for more information about this AD.

Material Incorporated by Reference

    (m) None.

    Issued in Burlington, Massachusetts, on December 11, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
 [FR Doc. E8-30049 Filed 12-19-08; 8:45 am]

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