98-6946. Airworthiness Directives; Glaser-Dirks Flugzeugbau GmbH Model DG- 400 Gliders  

  • [Federal Register Volume 63, Number 52 (Wednesday, March 18, 1998)]
    [Proposed Rules]
    [Pages 13151-13153]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 98-6946]
    
    
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    Proposed Rules
                                                    Federal Register
    ________________________________________________________________________
    
    This section of the FEDERAL REGISTER contains notices to the public of 
    the proposed issuance of rules and regulations. The purpose of these 
    notices is to give interested persons an opportunity to participate in 
    the rule making prior to the adoption of the final rules.
    
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    Federal Register / Vol. 63, No. 52 / Wednesday, March 18, 1998 / 
    Proposed Rules
    
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    DEPARTMENT OF TRANSPORTATION
    
    Federal Aviation Administration
    
    14 CFR Part 39
    
    [Docket No. 98-CE-14-AD]
    RIN 2120-AA64
    
    
    Airworthiness Directives; Glaser-Dirks Flugzeugbau GmbH Model DG-
    400 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 Glaser-Dirks Flugzeugbau GmbH (Glaser-Dirks) 
    Model DG-400 gliders. The proposed AD would require replacing the upper 
    rubber shock mounts with mounts made of stainless steel. The proposed 
    AD would also require inspecting the rear plate of the propeller mount 
    for cracks and proper mounting, and replacing or modifying as 
    necessary. 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 failure of the propeller suspension system caused by cracks in 
    the propeller mounts, which could result in loss of the propeller with 
    consequent reduced glider controllability.
    
    DATES: Comments must be received on or before April 17, 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-14-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 DG Flugzeugbau GmbH, Postfach 4120, D-76625 Bruchsal 4, Germany; 
    telephone: +49 7257-89-0; facsimile: +49 7257-8922. This information 
    also may be examined at the Rules Docket at the address above.
    
    FOR FURTHER INFORMATION CONTACT: Mr. J. Mike Kiesov, Aerospace 
    Engineer, Small Airplane Directorate, Aircraft Certification Service, 
    FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64106; telephone: 
    (816) 426-6934; 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, 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-14-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-14-AD, Room 1558, 601 E. 12th Street, Kansas 
    City, Missouri 64106.
    
    Discussion
    
        The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority 
    for Germany, recently notified the FAA that an unsafe condition may 
    exist on all Glaser-Dirks Model DG-400 gliders. The LBA reports 
    incidents where engine vibrations caused cracks at the upper rubber 
    shock mounts and, in one incident caused a crack at the rear plate of 
    the propeller mount.
        These conditions, if not corrected, could result in failure of the 
    propeller suspension system, which could lead to loss of the propeller 
    with consequent reduced glider controllability.
    
    Relevant Service Information
    
        Glaser-Dirks has issued Technical Note No. 826/11, dated August 29, 
    1984, which specifies replacing the upper rubber shock mounts with 
    mounts made of stainless steel. This technical note also includes 
    procedures for:
    
    --inspecting the rear plate of the propeller mount for cracks and an 
    excessive gap between the aluminum blocks and the plate (more than 1 mm 
    or .04 inches); and
    --installing washers if an excessive gap exists between the aluminum 
    blocks and the plate.
    
        The LBA classified this service bulletin as mandatory and issued 
    German AD 84-157, dated September 24, 1984, 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.
    
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    Explanation of the Provisions of the Proposed AD
    
        Since an unsafe condition has been identified that is likely to 
    exist or develop in other Glaser-Dirks Model DG-400 gliders of the same 
    type design registered in the United States, the FAA is proposing AD 
    action. The proposed AD would require the following:
    
    --replacing the upper rubber shock mounts with mounts made of stainless 
    steel;
    --inspecting the rear plate of the propeller mount for cracks and an 
    excessive gap between the aluminum blocks and the plate (more than 1 mm 
    or .04 inches);
    --replacing the rear plate of the propeller mount if cracks are found; 
    and
    --installing washers if an excessive gap exists between the aluminum 
    blocks and the plate.
    
        Accomplishment of the proposed shock mounts replacement, the 
    proposed inspections, and the proposed installation would be required 
    in accordance with the technical note previously referenced. 
    Accomplishment of the proposed propeller mount replacement, as 
    required, would be required in accordance with the applicable 
    maintenance manual.
    
    Difference Between the Technical Note, German AD, and This Proposed 
    AD
    
        Both Glaser-Dirks Technical Note No. 826/11, dated August 29, 1984, 
    and German AD 84-157, dated September 24, 1984, both specify 
    accomplishing the actions proposed in this AD prior to further flight. 
    The FAA does not have justification for requiring the proposed action 
    prior to further flight. Instead, the FAA has determined that 3 
    calendar months is a reasonable time period for accomplishing the 
    actions in the proposed AD.
    
    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) because of the typical 
    usage of the affected gliders. For example, an operator of an affected 
    glider may only utilize the glider 50 hours TIS in a year, while 
    another operator may utilize an affected glider 50 hours TIS in one 
    month. The FAA has determined that a compliance based on calendar time 
    should be utilized in the proposed AD in order to assure that the 
    unsafe condition is addressed on all gliders in a reasonable time 
    period.
    
    Cost Impact
    
        The FAA estimates that 35 gliders in the U.S. registry would be 
    affected by the proposed AD, that it would take approximately 6 
    workhours per glider to accomplish the proposed action, and that the 
    average labor rate is approximately $60 an hour. Parts cost 
    approximately $100 per glider. Based on these figures, the total cost 
    impact of the proposed AD on U.S. operators is estimated to be $16,100, 
    or $460 per glider.
    
    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:
    
    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:
    
    Glaser-Dirks Flugzeugbau GMBH: Docket No. 98-CE-14-AD.
    
        Applicability: Model DG-400 gliders, all serial numbers, 
    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 failure of the propeller suspension system caused by 
    cracks in the propeller mounts, which could result in loss of the 
    propeller with consequent reduced glider controllability, accomplish 
    the following:
        (a) Within the next 3 calendar months after the effective date 
    of this AD, replace the upper rubber shock mounts with mounts made 
    of stainless steel in accordance with the Instructions section of 
    Glaser-Dirks Technical Note TN 826/11, dated August 29, 1984.
        (b) Within the next 3 calendar months after the effective date 
    of this AD, inspect (using 2 x  or greater lens) the rear plate of 
    the propeller mount for cracks and an excessive gap between the 
    aluminum blocks and the plate (more than 1 mm or .04 inches). 
    Accomplish these inspections in accordance with the Instructions 
    section of Glaser-Dirks Technical Note TN 826/11, dated August 29, 
    1984.
        (1) If any cracks are found in the propeller mount, prior to 
    further flight, replace the propeller mount with an uncracked mount 
    in accordance with the applicable maintenance manual.
        (2) If an excessive gap exists between the aluminum blocks and 
    the plate, prior to further flight, install washers in accordance 
    with the Instructions section of Glaser-Dirks Technical Note TN 826/
    11, dated August 29, 1984.
        (c) 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.
        (d) An alternative method of compliance or adjustment of the 
    compliance times 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
    
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    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.
    
        (e) Questions or technical information related to Glaser-Dirks 
    Technical Note No. 826/11, dated August 29, 1984, should be directed 
    to DG Flugzeugbau GmbH, Postfach 4120, D-76625 Bruchsal 4, Germany; 
    telephone: +49 7257-89-0; facsimile: +49 7257-8922. 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 84-157, 
    dated September 24, 1984.
    
        Issued in Kansas City, Missouri, on March 10, 1998.
    Michael Gallagher,
    Manager, Small Airplane Directorate, Aircraft Certification Service.
    [FR Doc. 98-6946 Filed 3-17-98; 8:45 am]
    BILLING CODE 4910-13-P
    
    
    

Document Information

Published:
03/18/1998
Department:
Federal Aviation Administration
Entry Type:
Proposed Rule
Action:
Notice of proposed rulemaking (NPRM).
Document Number:
98-6946
Dates:
Comments must be received on or before April 17, 1998.
Pages:
13151-13153 (3 pages)
Docket Numbers:
Docket No. 98-CE-14-AD
RINs:
2120-AA64: Airworthiness Directives
RIN Links:
https://www.federalregister.gov/regulations/2120-AA64/airworthiness-directives
PDF File:
98-6946.pdf
CFR: (1)
14 CFR 39.13