Discussion
What events have caused this AD? The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, recently notified FAA that an unsafe condition may exist on certain DG Flugzeugbau GmbH Model DG-500MB sailplanes, all serial numbers up to and including 5E220B15. The LBA reports two separate fatigue failures of the Warner LA10 spindle drive.
What is the potential impact if FAA took no action? Failure of the Warner LA10 spindle drive could result in the engine pylon not rising or lowering, which could cause an unstable engine pylon assembly during flight. Failure of the engine pylon assembly during flight could result in loss of control of the sailplane.
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 certain DG Flugzeugbau GmbH Model DG- 500MB sailplanes. This proposal was published in the FederalRegister as a notice of proposed rulemaking (NPRM) on May 20, 2004 (69 FR 29106). The NPRM proposed to require you to replace the Warner LA10 spindle drive with the Stross BSA 10 spindle drive and to modify the electrical system following Technical Note No. 843/18, issue 2, dated June 25, 2003.
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 4 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 accomplish the replacement and modification:
Labor cost
Parts cost
Total cost per sailplane
Total cost on U.S. operators
12 work hours est. $65 per hour = $780
$2,662
$3,442
$13,768
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 placed it in the AD Docket. You may get acopy of this summary by sending a request to us at the address listed under ADDRESSES. Include "AD Docket No. 2004-CE-06-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: