Relevant Service Information

Grob Aerospace has issued Service Bulletin No. MSB 31576/1 and 869 27/1 (same document), dated June 23, 2008. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of the Proposed AD

This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to our bilateral agreement with this State of Design Authority, they have notified us of the unsafe condition described in the MCAI and service information referenced above. We are proposing this AD because we evaluated all information and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design.
Differences Between This Proposed AD and the MCAI or Service Information

We have reviewed the MCAI and related service information and, in general, agree with their substance. But we might have found it necessary to use different words from those in the MCAI to ensure the AD is clear for U.S. operators and is enforceable. In making these changes, we do not intend to differ substantively from the information provided in the MCAI and related service information.

We might also have proposed different actions in this AD from those in the MCAI in order to follow FAA
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policies. Any such differences are highlighted in a NOTE within the proposed AD.

Costs of Compliance

We estimate that this proposed AD will affect 129 products of U.S. registry. We also estimate that it would take about 1 workhour per product to comply with the basic requirements of this proposed AD. The average labor rate is $80 per workhour. Required parts would cost about $15 per product.

Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $12,255, or $95 per product.

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 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 this 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 and placed it in the AD docket. 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 39AIRWORTHINESS 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 AD: Burkhart Grob LuftUnd Raumfahrt GmbH & CO KG: Docket No. FAA2008 1078; Directorate Identifier 2008CE051AD.
Comments Due Date
(a) We must receive comments by November 10, 2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to the following models and serial numbers (SNs) gliders, certificated in any category:
(1) G103 TWIN II, SNs 3730 through 3878;
(2) G103A TWIN II ACRO, SNs 3730 through 34078 (K);
(3) G103C TWIN III ACRO, SNs 34101 through 34203; and
(4) G 103 C TWIN III SL, SNs 35001 through 35051
Subject
(d) Air Transport Association of America (ATA) Code 27: Flight Controls.
Reason
(e) The mandatory continuing airworthiness information (MCAI) states:

The LuftfahrtBundesamt received a report from the Grob Company that a bolt in the airbrake control was found failed during a pre flight inspection on a G 103C TWIN III ACRO. During an extensive investigation (metallurgical investigation) a double sided fatigue crack was found as root cause. As the bolt is insignificantly stressed by cyclic bending the crack was probably caused by mean stress supported by a bolt torque exceeding the limit. The actions specified by this airworthiness directive are intended to prevent further bolt cracking which can result in airbrake as well as elevator failure (elevator control is on the same pedestal) and reduced controllability of the power glider.

The MCAI requires replacement of bolt LN9037M6x60 from the airbrake bell crank 103B4437 with a new bolt with a new locking nut and tightening the bolt to a specific torque; check of all parts of the airbrake bell crank and the attachment parts for any damage and replacement of any damaged parts; check of the airbrake locking force of the lefthand and righthand wing for a specific force value range and that the locking is clearly noticeable; and check of the airbrake locking force at the operating lever in the front cockpit with the wings rigged for a specific force value range. Actions and Compliance
(f) Unless already done, within 60 days after the effective date of this AD, do the following actions following Grob Aerospace Service Bulletin No. MSB 31576/1 and No. 86927/1 (same document), dated June 23, 2008:
(1) Remove bolt LN9037M6x60 from the airbrake bell crank 103B 4437 and install a new bolt LN9037M6x60 with the new locking nut LN9348M6 and torque the bolt to 6.4 Nm (4.7 lbs.ft).
(2) Inspect all parts of the airbrake bell crank including the attachment parts for any damage and, before further flight, replace any damaged parts.
(3) Inspect the airbrake locking force of the lefthand (LH) and righthand (RH) wing using a spring balance. The force must be equal for the LH and RH wing (guidance value: 102 daN, (22.54.5 lbs)) and the locking must be clearly
noticeable.
(4) Inspect the airbrake locking force at the operating lever in the front cockpit with the wings rigged. The guidance value is 102 daN, (22.54.5 lbs). It must not exceed 1520 daN (33.745.0 lbs).

FAA AD Differences

Note: This AD differs from the MCAI and/or service information as follows: No differences.
Other FAA AD Provisions
(g) The following provisions also apply to this AD:
(1) Alternative Methods of Compliance (AMOCs): The Manager, Standards Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Greg Davison, Glider Program Manager, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 3294130; fax: (816) 3294090. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.
(2) Airworthy Product: For any requirement in this AD to obtain corrective actions from a manufacturer or other source, use these actions if they are FAAapproved. Corrective actions are considered FAAapproved if they are approved by the State of Design Authority (or their delegated agent). You are required to assure the product is airworthy before it is returned to service.
(3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 21200056.
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Related Information
(h) Refer to MCAI Federal Republic of Germany Luftfahrt Bundesamt AD D2008231, dated July 11, 2008; and AD D2008232, dated July 11, 2008; and Grob Aerospace Service Bulletin No. MSB 31576/1 and No. 86927/1 (same document), dated June 23, 2008, for related information.

Issued in Kansas City, Missouri, on October 2, 2008. Kim Smith,
Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. E823973 Filed 10808; 8:45 am]
BILLING CODE 491013P

FOR FURTHER INFORMATION CONTACT Greg Davison, Glider Program Manager, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 3294130; fax: (816) 3294090.