AD 98-24875

[Federal Register Volume 63, Number 180 (Thursday, September 17, 1998)] [Proposed Rules] [Pages 49673-49675] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 98-24875]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-CE-71-AD] RIN 2120-AA64

Airworthiness Directives; Burkhart GROB Luft-und Raumfahrt GmbH Model G 109B Gliders

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new airworthiness directive (AD) that would apply to certain Burkhart GROB Luft-und Raumfahrt GmbH (Grob) Model G 109B gliders. The proposed AD would require inspecting the elevator and trim tab for water and to assure that the necessary drain holes are installed and that the existing drain holes are open. The proposed AD would also require drilling any necessary drain holes and opening any existing drain holes that are closed; and, if a significant amount of water (more than \1/2\ liter) is found in the elevator, assuring that the glider's residual momentum and center of gravity (C.G.) are within the limits specified in the flight manual, and adjusting the residual momentum and C.G., as needed. The proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Germany. The actions specified by the proposed AD are intended to prevent water from penetrating the elevator and trim tab because of inadequate drainage, which could result in a delaminated elevator and trim tab structure with consequent elevator imbalance and flutter.

DATES: Comments must be received on or before October 19, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-CE-71-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. Comments may be inspected at this location between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted. Service information that applies to the proposed AD may be obtained from Burkhart Grob Luft-und Raumfahrt, D-8939 Mattsies, Germany. This information also may be examined at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. Mike Kiesov, Aerospace Engineer, FAA, Small Airplane Directorate, 1201 Walnut, suite 900, Kansas City, Missouri 64106; telephone: (816) 426-6932; facsimile: (816) 426-2169.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. Comments are specifically invited on the overall regulatory, economic,

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environmental, and energy aspects of the proposed 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 proposal will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket No. 98-CE-71-AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-CE-71-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

Discussion

The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, notified the FAA that an unsafe condition may exist on certain Grob Model G 109B gliders. The LBA reports that the above- referenced gliders may not have an adequate number of drain holes in the elevator and trim tab. Inadequate elevator and trim tab drainage, if not corrected in a timely manner, could result in water penetrating the elevator and trim tab. This could lead to a delaminated elevator and trim tab structure with consequent elevator imbalance and flutter.

Relevant Service Information

Grob has issued Service Bulletin TM 817-35, dated July 20, 1992, which specifies procedures for inspecting the elevator and trim tab for water and to assure that the necessary drain holes are installed and that the existing drain holes are open. The service bulletin also specifies drilling any necessary drain holes and opening any existing drain holes that are closed; and, if a significant amount of water (more than \1/2\ liter) is found in the elevator, assuring that the glider's residual momentum and C.G., are within the limits specified in the flight manual, and adjusting the residual momentum and C.G., as needed. The LBA classified this service bulletin as mandatory and issued German AD 92-350 Grob, dated October 26, 1992, in order to assure the continued airworthiness of these gliders in Germany.

The FAA's Determination

This glider 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 the Proposed AD

Since an unsafe condition has been identified that is likely to exist or develop in other Grob G 109B gliders of the same type design registered in the United States, the FAA is proposing AD action. The proposed AD would require inspecting the elevator and trim tab for water and to assure that the necessary drain holes are installed and that the existing drain holes are open. The AD would also require drilling any necessary drain holes and opening any existing drain holes that are closed; and, if a significant amount of water (more than \1/2\ liter) is found in the elevator, assuring that the glider's residual momentum and C.G. are within the limits specified in the flight manual, and adjusting the residual momentum and C.G, as needed. Accomplishment of the proposed actions would be in accordance with Grob Service Bulletin TM 817-35, dated July 20, 1992.

Cost Impact

The FAA estimates that 20 gliders in the U.S. registry would be affected by the proposed AD, that it would take approximately 1 workhour per glider to accomplish the proposed inspection, and that the average labor rate is approximately $60 an hour. Based on these figures, the total cost impact of the proposed inspection on U.S. operators is estimated to be $1,200, or $60 per glider. If drain holes need to be added, the FAA estimates that it would take approximately 1 workhour per glider to accomplish the proposed modification, and that the average labor rate is approximately $60 an hour. Based on these figures, the total cost impact of the proposed modification on U.S. operators is estimated to be $60 per glider that would need drain holes installed.

Compliance Time of the Proposed AD

The compliance time of the proposed AD is presented in calendar time instead of hours time-in-service (TIS). The unsafe condition is not a result of the number of times the glider is operated. If the elevator and trim tab of the affected gliders have inadequate drainage, then water could penetrate the elevator and trim tab on the first flight, as well as subsequent flights. The delamination and imbalance that could then occur can happen in a very short period of time or happen over a long period of time. For these reasons, the FAA has determined that a compliance based on calendar time should be utilized in this AD in order to assure that the unsafe condition is addressed on all gliders in a reasonable time period.

Regulatory Impact

The regulations proposed herein would 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 proposal would 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) if promulgated, 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 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, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

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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.

Sec. 39.13 [Amended]

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

Burkhart Grob Luft-und Raumfahrt GMBH: Docket No. 98-CE-71-AD. Applicability: Model G 109B gliders, all serial numbers beginning with 6200, certificated in any category.

Note 1: This AD applies to each glider 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 gliders 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 (d) 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 as indicated in the body of this AD, unless already accomplished. To prevent water from penetrating the elevator and trim tab because of inadequate drainage, which could result in a delaminated elevator and trim tab structure with consequent elevator imbalance and sailplane flutter, accomplish the following: (a) Within the next 6 calendar months after the effective date of this AD, inspect the elevator and trim tab for water and to assure that the necessary drain holes are installed and that the existing drain holes are open. Accomplish these actions in accordance with the Actions section of Grob Service Bulletin TM 817- 35, dated July 20, 1992. Prior to further flight after the inspection, accomplish the following as specified in the service bulletin: (1) Drill any necessary drain holes and open any existing drain holes that are closed; and, (2) If a significant amount of water (more than 1/2 liter ) is found in the elevator, assure that the glider's residual momentum and center of gravity (C.G.) are within the limits specified in the flight manual, and adjust the residual momentum and C.G, as needed. (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 glider to a location where the requirements of this AD can be accomplished. (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, 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Small Airplane Directorate.

(d) Questions or technical information related to Grob Service Bulletin TM 817-35, dated July 20, 1992, should be directed to Burkhart Grob Luft-und Raumfahrt, D-8939 Mattsies, Germany. This service information may be examined at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

Note 3: The subject of this AD is addressed in German AD 92-350 Grob, dated October 26, 1992.

Issued in Kansas City, Missouri, on September 9, 1998. Michael Gallagher, Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-24875 Filed 9-16-98; 8:45 am] BILLING CODE 4910-13-U