2010-20877. Airworthiness Directives; Aircraft Industries a.s. (Type Certificate G24EU Previously Held by LETECKÉ ZÁVODY a.s. and LET Aeronautical Works) Model L-13 Blanik Gliders

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

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

A fatal accident occurred to a L-13 BLANÍK sailplane, in which the main spar of the right wing failed near the root due to positive load. The right wing detached from the aircraft and the pilots lost control of the sailplane.

The preliminary investigation has revealed that the fracture may have been due to fatigue.

The AD 2010-0119-E required immediate inspection of the main spar at the root of the wing to detect fatigue cracking and the accomplishment of the relevant corrective actions as necessary. In addition, the AD 2010-0119-E imposed operational limitations. AD 2010-0122-E retained the requirements of AD 2010-0119-E, which is superseded, and extended the applicability to L-13 A BLANÍK sailplanes.

This AD requires actions that are intended to address the unsafe condition described in the MCAI.

DATES:

This AD becomes effective August 30, 2010.

We must receive comments on this AD by October 12, 2010.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​; or in person at the Docket Management Facility 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 Office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Greg Davison, Aerospace Engineer, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106, telephone: [phone], fax: [phone].

SUPPLEMENTARY INFORMATION:

Discussion

On June 28, 2010, we issued AD 2010-14-15, Amendment 39-16360 (75 FR 39795), dated July 13, 2010. That AD required actions intended to address an unsafe condition on the products listed above.

Since we issued AD 2010-14-15, we have received preliminary information from the European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, that identified fatigue as the failure mode in the fatal accident. The examination of the fractures in the wing flange straps found eight areas of fatigue cracking that originated from the surface of the bores used to rivet the flange straps to the hinge. The fatigue cracks had propagated to the surface of the flange straps and were not visible for inspection.

In addition, we received several public comments indicating that the use of a 10X magnifier is not appropriate to assess the specified inspection areas and portions of the operational data requested by the current AD are not required for U.S. operators.

EASA has issued Emergency AD No. 2010-0160-E, dated July 30, 2010 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

A fatal accident occurred to a L-13 BLANÍK sailplane, in which the main spar of the right wing failed near the root due to positive load. The right wing detached from the aircraft and the pilots lost control of the sailplane.

The preliminary investigation has revealed that the fracture may have been due to fatigue.

The AD 2010-0119-E required immediate inspection of the main spar at the root of the wing to detect fatigue cracking and the accomplishment of the relevant corrective actions as necessary. In addition, the AD 2010-0119-E imposed operational limitations. AD 2010-0122-E retained the requirements of AD 2010-0119-E, which is superseded, and extended the applicability to L-13 A BLANÍK sailplanes.

The requirements of AD 2010-0122-E were considered as interim action to immediately address the unsafe condition. Since issuance of AD 2010-0122-E, based on further information provided by the Austrian Accident Investigation Board, EASA has re-assessed the inspection method as described in Aircraft Industries a.s. Mandatory Bulletin No. L13/109a. EASA now concludes that the inspection method might not be sufficient for detecting the crack which means that the unsafe condition might still be present even if the sailplane has passed the inspection required by AD 2010-0122-E. Furthermore, the Type Certificate Holder indicates that it is extremely important to remain within the flight limitations specified in the Aircraft Industries a.s. Mandatory Bulletin No. L13/109a. For this reason, this AD further requires a record checking for determining if the sailplane has been operated within the flight limitations.

For all the reasons stated above, as a precautionary measure, this AD is prohibiting operations when a sailplane does not pass the requirements of this AD. For those sailplanes, EASA is currently working with the Type Certificate Holder. When, as a result of the on-going investigation, a solution is later identified, further mandatory action is likely to follow.

You may obtain further information by examining the MCAI in the AD docket.

FAA's Determination and Requirements of the 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 issuing this AD because we evaluated all information provided by the State of Design Authority and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design.

Differences Between This 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 have also required different actions in this AD from those in the MCAI in order to follow FAA policies. Any such differences are described in a separate paragraph of the AD. These requirements take precedence over those copied from the MCAI.

FAA's Determination of the Effective Date

An unsafe condition exists that requires the immediate adoption of this AD. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because a fatal accident occurred in an L-13 Blanik glider. The main spar of the right wing of the accident glider failed near the root due to positive load. The right wing detached from the aircraft and the pilots lost control. The preliminary investigation has revealed that the fracture may have been due to fatigue. Therefore, 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 opportunity for public comment. We invite you to send any written relevant data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2010-0839; Directorate Identifier 2010-CE-042-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about 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.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• 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 removing Amendment 39-16360 ( 75 FR 39795), dated July 13, 2010, and adding the following new AD:

2010-18-05 Aircraft Industries a.s. (Type Certificate G24EU Previously Held by Letecké Závody a.s. and LET Aeronautical Works): Amendment 39-16418; Docket No. FAA-2010-0839; Directorate Identifier 2010-CE-042-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective August 30, 2010.

Affected ADs

(b) This AD supersedes AD 2010-14-15; Amendment 39-16360.

Applicability

(c) This AD applies to Aircraft Industries a.s. L-13 Blanik gliders, all serial numbers, certificated in any category.

Subject

(d) Air Transport Association of America (ATA) Code 57: Wings.

Reason

(e) The mandatory continuing airworthiness information (MCAI) states:

A fatal accident occurred to a L-13 BLANÍK sailplane, in which the main spar of the right wing failed near the root due to positive load. The right wing detached from the aircraft and the pilots lost control of the sailplane.

The preliminary investigation has revealed that the fracture may have been due to fatigue.

The AD 2010-0119-E required immediate inspection of the main spar at the root of the wing to detect fatigue cracking and the accomplishment of the relevant corrective actions as necessary. In addition, the AD 2010-0119-E imposed operational limitations. AD 2010-0122-E retained the requirements of AD 2010-0119-E, which is superseded, and extended the applicability to L-13 A BLANÍK sailplanes.

The requirements of AD 2010-0122-E were considered as interim action to immediately address the unsafe condition. Since issuance of AD 2010-0122-E, based on further information provided by the Austrian Accident Investigation Board, EASA has re-assessed the inspection method as described in Aircraft Industries a.s. Mandatory Bulletin No. L13/109a. EASA now concludes that the inspection method might not be sufficient for detecting the crack which means that the unsafe condition might still be present even if the sailplane has passed the inspection required by AD 2010-0122-E. Furthermore, the Type Certificate Holder indicates that it is extremely important to remain within the flight limitations specified in the Aircraft Industries a.s. Mandatory Bulletin No. L13/109a. For this reason, this AD further requires a record checking for determining if the sailplane has been operated within the flight limitations.

For all the reasons stated above, as a precautionary measure, this AD is prohibiting operations when a sailplane does not pass the requirements of this AD. For those sailplanes, EASA is currently working with the Type Certificate Holder. When, as a result of the on-going investigation, a solution is later identified, further mandatory action is likely to follow.

Actions and Compliance

(f) To address this problem, before further flight after August 30, 2010 (the effective date of this AD), incorporate an FAA-approved inspection and/or modification program developed specifically for this AD. Corrective action is considered FAA-approved if it is 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.

FAA AD Differences

Note:

This AD differs from the MCAI and/or service information as follows: The MCAI requires the owner/operator to submit data regarding certain operations including aerobatic operations, to the European Aviation Safety Agency (EASA) and Aircraft Industries, a.s. so they can determine whether further flight is permitted. The FAA does not require such data to be collected for operations in the United States. The FAA is relying on an inspection and/or modification program approved specifically for this AD to detect and correct cracks before further flight. Until such a program is approved, owners/operators may apply for an alternative method of compliance (AMOC) following 14 CFR 39.19 described in paragraph (f)(1) of this AD. The FAA will work with EASA and Aircraft Industries a.s. to determine if an acceptable level of safety is achieved with the AMOC proposal.

Other FAA AD Provisions

(f) 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, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: [phone]; fax: [phone]. 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 FAA-approved. Corrective actions are considered FAA-approved 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 2120-0056.

Special Flight Permit

(g) Under 14 CFR part 39.23, we are limiting the special flight permits for this AD by prohibiting aerobatic maneuvers.

Related Information

(h) Refer to MCAI EASA Emergency AD No. 2010-0160-E, dated July 30, 2010, for related information. For future service information that may be developed to address the unsafe condition specified in this AD, contact Aircraft Industries, a.s., Na Záhonech 1177, 686 04 Kunovice, Czech Republic; telephone: [phone]; fax: [phone]; Internet: http://www.let.cz/;;; e-mail: [e-mail].

Issued in Kansas City, Missouri, on August 17, 2010.

John Colomy,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.