05-7990. Airworthiness Directives; LET a.s. Model Blanik L-13 AC Sailplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

The FAA adopts a new airworthiness directive (AD) for all LET a.s. (formerly LET n.p.) (LET) Model Blanik L-13 AC sailplanes. This AD requires you to replace the original control bridge with the new strengthened control column mounting bridge. This AD is the result of a report of one case of cracks in the attachment of control levers on the control bridge. We are issuing this AD to correct cracks in the bedding of the front and rear control levers, which could result in failure of the control bridge for the sailplane. This failure could lead to loss of sailplane control.

DATES:

This AD becomes effective on June 6, 2005.

As of June 6, 2005, the Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulation.

ADDRESSES:

You may get the service information identified in this AD from LET a.s., Kunovice 686 04, Czech Republic; telephone: [phone]; facsimile: [phone].

You may view the AD docket at FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2003-CE-57-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. Office hours are 8 a.m. to 4 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT:

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

SUPPLEMENTARY INFORMATION:

Discussion

What Events Have Caused This AD?

The Civil Aviation Authority (CAA), which is the airworthiness authority for the Czech Republic, recently notified FAA that an unsafe condition may exist on certain LET Model Blanik L-13 AC sailplanes. The CAA reports one case of cracks in the attachment of control levers on the control bridge (Drawing No. A71 210N) on a Model Blanik L-13 AC sailplane after 130 hours time-in-service (TIS) of aerobatics. The cracks are because of material fatigue.

What Is the Potential Impact if FAA Took No Action?

Failure of the control bridge for the sailplane could lead to loss of sailplane control.

Has FAA Taken Any Action to This Point?

We issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to all LET a.s. (formerly LET n.p.) (LET) Model Blanik L-13 AC sailplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on March 9, 2004 (69 FR 10939). The NPRM proposed to require you to repetitively inspect the bedding of the front and rear control levers for cracks, and, if any cracks are found, replace with parts found free of cracks.

You would have to do the proposed actions following Letecke Zavody Mandatory Bulletin No.: L13/095a, dated October 18, 2001.

Since issuance of the NPRM, LET has issued the new Letecke Zavody Mandatory Bulletin No.: L13AC/014a, dated July 17, 2003. This service bulletin removes the repetitive inspection, requires the replacement of parts, and changes the serial numbers affected.

The CAA has not amended the Czech AD to reflect this service information. However, FAA has evaluated the new service information and determined that the NPRM should be changed to reflect the requirements in the new LET service bulletin.

A supplemental NPRM proposal was published in the Federal Register on October 7, 2004 (69 FR 60106). The supplemental NPRM proposed to require you to replace the original control bridge with the new strengthened control column mounting bridge.

Comments

Was the Public Invited To Comment?

We provided the public the opportunity to participate in developing this AD. We received no comments on the proposal or on the determination of the cost to the public.

Conclusion

What Is FAA's Final Determination on This Issue?

We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed except for minor editorial corrections. We have determined that these minor corrections:

—Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and

—Do not add any additional burden upon the public than was already proposed in the NPRM.

Changes to 14 CFR Part 39—Effect on the AD

How Does the Revision to 14 CFR Part 39 Affect This AD?

On July 10, 2002, the FAA published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.

Costs of Compliance

How Many Sailplanes Does This AD Impact?

We estimate that this AD affects 5 sailplanes in the U.S. registry.

What Is the Cost Impact of This AD on Owners/Operators of the Affected Sailplanes?

We estimate the following costs to do the replacement:

Labor cost	Parts cost	Total cost for each airplane	Total cost on U.S. operators
7 workhours × $65 for each hour = $455	$2,000	$2,455	$12,275

Authority for This Rulemaking

What Authority Does FAA Have for Issuing This Rulemaking Action?

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 AD.

Regulatory Findings

Will This AD Impact Various Entities?

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.

Will This AD Involve a Significant Rule or Regulatory Action?

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 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 summary of the costs to comply with this AD (and other information as included in the Regulatory Evaluation) and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 2003-CE-57-AD” in your request.

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 Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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. FAA amends § 39.13 by adding a new AD to read as follows:

2005-08-14 LET a.s. (Formerly LET n.p.): Amendment 39-14066; Docket No. 2003-CE-57-AD.

When Does This AD Become Effective?

(a) This AD becomes effective on June 6, 2005.

What Other ADs Are Affected by This Action?

(b) None.

What Sailplanes Are Affected by This AD?

(c) This AD affects Model Blanik L-13 AC sailplanes, serial numbers 988601, 988603, 008605, 008606, and 028902, that are certificated in any category.

What Is the Unsafe Condition Presented in This AD?

(d) This AD is the result of a report of one case of cracks in the attachment of control levers on the control bridge. The actions specified in this AD are intended to correct cracks in the bedding of the front and rear control levers, which could result in failure of the control bridge for the sailplane. This failure could lead to loss of sailplane control.

What Must I Do To Address This Problem?

(e) To address this problem, you must do the following:

Actions	Compliance	Procedures
(1) Replace the original control bridge (Drawing No. A741 210N) with the new strengthened control column mounting bridge (Drawing No. A740 370N)	Within the next 25 hours time-in-service (TIS) after June 6, 2005 (the effective date of this AD), unless already done	Follow the WORK PROCEDURE paragraph of LET Letecke Zavody Mandatory Bulletin No.: L13AC/014a, dated July 17, 2003.
(2) Do not install any original control bridge (Drawing No. A741 210N)	As of the effective date of this AD	Not Applicable.

May I Request an Alternative Method of Compliance?

(f) You may request a different method of compliance or a different compliance time for this AD by following the procedures in 14 CFR 39.19. Unless FAA authorizes otherwise, send your request to your principal inspector. The principal inspector may add comments and will send your request to the Manager, Standards Office, FAA. For information on any already approved alternative methods of compliance, contact Greg Davison, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: [phone]; facsimile: [phone].

Does This AD Incorporate Any Material by Reference?

(g) You must do the actions required by this AD following the instructions in LET Letecke Zavody Mandatory Bulletin No.: L13AC/014a, dated July 17, 2003. The Director of the Federal Register approved the incorporation by reference of this service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may get a copy from LET a.s., Kunovice 686 04, Czech Republic; telephone: [phone]; facsimile: [phone]. You may review copies at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call [phone], or go to: http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

Is There Other Information That Relates to This Subject?

(h) Czech Airworthiness Directive CAA-AD-090/2001, dated October 25, 2001, also addresses the subject of this AD.

Issued in Kansas City, Missouri, on April 14, 2005.

Nancy C. Lane,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.