Discussion
The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, recently notified the FAA that an unsafe condition may exist on certain Stemme Model S10 sailplanes. The LBA reports that the flap drive rocker, P/N 10SW-RMW, is likely to fail due to fatigue. This was revealed following failure of a different part in the flight control system. The manufacturer then performed an analysis on other critical points, which revealed the flap drive rocker condition.
This condition, if not corrected, could result in failure of the flap drive rocker and loss of lateral control and wing flap control with consequent reduced and/or loss of sailplane control.
Relevant Service Information
Stemme has issued Service Bulletin No. A31-10-017, Amendment-Index 02.a, dated May 20, 1998, which specifies procedures for replacing the flap drive rocker, P/N 10SW-RMW, with a modified P/N 10SW-RMW flap drive rocker. This service bulletin alsospecifies obtaining this modified part from the manufacturer.
The LBA classified this service bulletin as mandatory and issued German AD 1998-324, dated July 30, 1998, in order to assure the continued airworthiness of these sailplanes in Germany.
The FAA's Determination
This sailplane model is manufactured in Germany and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the LBA has kept the FAA informed of the situation described above.
The FAA has examined the findings of the LBA; reviewed all available information, including the service information referenced above; and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.
Explanation of the Provisions of This AD
Since an unsafe condition hasbeen identified that is likely to exist or develop in other Stemme Model S10 sailplanes of the same type design, the FAA is issuing an AD. This AD requires replacing the flap drive rocker, P/N 10SW-RMW, with a modified P/N 10SW-RMW flap drive rocker. The actions are to be done in accordance with Stemme Service Bulletin No. A31-10-017, Amendment-Index 02.a, dated May 20, 1998.
Cost Impact
None of the Stemme Model S10 sailplanes affected by this action are on the U.S. Register. All sailplanes included in the applicability of this rule currently are operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, the FAA considers this rule necessary to ensure that the unsafe condition is addressed in the event that any of these subject sailplanes are imported and placed on the U.S. Register.
Should an affected sailplane be imported and placed on the U.S. Register, accomplishment of the required action would take approximately 5 workhours at an average labor rate of $60 per workhour. Parts cost approximately $200 per sailplane. Based on these figures, the total cost impact of this AD would be $500 per sailplane that would become registered in the United States.
The Effective Date of This AD
Since this AD action does not affect any sailplane that is currently on the U.S. register, it has no adverse economic impact and imposes no additional burden on any person. Therefore, notice and public procedures hereon are unnecessary and the amendment may be made effective in less than 30 days after publication in the Federal Register.
Comments Invited
Although this action is in the form of a final rule and was not preceded by notice and opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket No. 98-CE-103-AD." The postcard will be date stamped and returned to the commenter.
Regulatory Impact
The regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this action (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 substantialnumber of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action has been placed in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption "ADDRESSES".
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to 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. Section 39.13 is amended by adding a new airworthiness directive (AD) to read as follows: