AD 96-04-12 ACTIVE

This amendment adopts a new airworthiness directive (AD) that applies to certain Glaser-Dirks Flugzeugbau GmbH (Glaser-Dirks) DG-500M sailplanes. This action requires replacing the airbrake control hook-up shaft with a part of improved design. Reports of cracks in the welding of the lever to the torsion tube of the airbrake control prompted this action. The actions specified in this AD are intended to prevent an unintended extension of the airbrakes caused by failure of the lever to the torsion tube of the airbrake control, which could result in flutter, excessive rate of descent, and loss of control of the sailplane.

Final rule; request for comments

96-04-12 GLASER-DIRKS FLUGZEUGBAU GmbH: Amendment 39-9524; Docket 95-CE-16-AD.
Applicability: DG-500M sailplanes (serial numbers 5E30M14 through 5E60M25), certificated in any category.

NOTE 1: This AD applies to each sailplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For sailplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required prior to further flight after the effective date of this AD, unless already accomplished.

To prevent an unintended extension of the airbrakes caused by failure of the lever to the torsion tube of the airbrake control, which could result in flutter, excessive rate of descent, and loss of control of the sailplane, accomplish the following:

(a) Replace the airbrake control hook-up shaft (part number 5 St 57) with an airbrake control hook-up shaft of improved design (part number 5 St 57 change b). Accomplishment of the replacement is in accordance with the applicable maintenance or service manual.

NOTE 2: Glaser-Dirks Technical Note No. 843/3-2, dated October 28, 1992, references an exchange program where improved design airbrake control hook-up shafts may be obtained at no cost.

(b) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the sailplane to a location where the requirements of this AD can beaccomplished.

(c) An alternative method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be approved by the Manager, Small Airplane Directorate, FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64106. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Small Airplane Directorate.

(d) All persons affected by this directive may obtain copies of the document referred to herein upon request to Glaser-Dirks Flugzeugbau GmbH, Im Schollengarten 19-20, D-78646 Buchsal-UnterGrombach 4, Germany; or may examine this document at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

(e) This amendment becomes effective on March 29, 1996.

The Luftfarht-Bundesant (LBA), which is the airworthiness authority for Germany, recently notified the FAA that an unsafe condition may exist on certain Glaser-Dirks DG-500M sailplanes. The LBA reports cracks in the welding of the lever to the torsion tube of the airbrake control. In one instance, the airbrake control failed, resulting in an unintended airbrake extension. If not detected and corrected, a cracked lever to the torsion tube of the airbrake control could result in an unintended extension of the airbrakes with subsequent possible flutter, excessive rate of descent, and loss of control of the sailplane.

Glaser-Dirks Technical Note (TN) No. 843/3-2, dated October 28, 1992, contains information about replacing the airbrake control hook-up shaft (part number 5 St 57) on DG-500M sailplanes with an airbrake control hook-up shaft of improved design (part number 5 St 57 change b). The LBA classified this technical note as mandatory and issuedLBA AD 92-358, dated October 30, 1992, in order to assure the continued airworthiness of these sailplanes in Germany.

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. The FAA has examined the findings of the LBA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Since an unsafe condition has been identified that is likely to exist or develop on other Glaser-Dirks DG-500M sailplanes of the same type design registered in the United States, this AD requires replacing the airbrake control hook-up shaft (part number 5 St 57) with an airbrake control hook-up shaft of improved design (part number 5 St 57 change b). Accomplishment of the replacement is in accordance with the applicable maintenance or service manual. Improved design airbrake control hook-up shafts may be obtained from Glaser-Dirks on an exchange basis.

None of the DG-500M 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 replacement and inspection would take approximately 8 workhours at an average labor charge of $60 per workhour. Parts are provided by Glaser-Dirks atno cost on an exchange basis. Based on these figures, the total cost impact of this AD would be $480 per sailplane that would become registered in the United States.

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.95-CE-16-AD." The postcard will be date stamped and returned to the commenter.

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 substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, 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 USC 106(g), 40113, 44701.

Section 39.13 - [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive (AD) to read as follows:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Central Region, Office of the Assistant Chief Counsel, Attention: Rules Docket 95-CE-16-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.
Service information that applies to this AD may be obtained from Glaser-Dirks Flugzeugbau GmbH, Im Schollengarten 19-20, D-78646 Buchsal-UnterGrombach 4, Germany. This information may also be examined at the Federal Aviation Administration (FAA), Central Region, Office of the Assistant Chief Counsel, Attention: Rules Docket No. 95-CE-16-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Mr. Herman Belderok, Project Officer, Sailplanes, FAA, Small Airplane Directorate, 1201 Walnut, suite 900, Kansas City, Missouri 64106; telephone (816) 426-6932; facsimile (816) 426-2169.