[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
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 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