[Federal Register Volume 63, Number 98 (Thursday, May 21, 1998)]
[Proposed Rules]
[Pages 27870-27872]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-13518]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-CE-07-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 all Glaser-Dirks Flugzeugbau GmbH (Glaser-
Dirks) Model DG-400 gliders. The proposed action would require 
replacing the propeller shaft, the bearings, and the front drive belt 
retaining rings with ones of improved design. 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 shaft, 
which could result in loss of glider propulsion during critical phases 
of flight.

DATES: Comments must be received on or before June 26, 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-07-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 Glaser-Dirks Flugzeugbau GmbH, Im Schollengarten 19-20, 7520 
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: Mike Kiesov, Aerospace Engineer, FAA, 
Small Airplane Directorate, Aircraft Certification Service, 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

[[Page 27871]]

statement is made: ``Comments to Docket No. 98-CE-07-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-07-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 that 
the propeller shafts installed on some of these Model DG-400 gliders 
have failed during flight. An LBA investigation of these incidents 
showed that the propeller shaft currently installed had a torque 
tensioning problem which was causing the shaft to rotate. In some 
cases, the propeller drive belt damaged the front retaining rings and 
came off the upper pulley, which also damaged the propeller.
    These conditions, if not corrected, could result in loss of 
propulsion during critical phases of flight.

Relevant Service Information

    DG Flugzeugbau has issued Technical Note No. 826/32, dated July 19, 
1996, and DG Flugzeugbau WORKING INSTRUCTION No. 1 for TN 826/32, dated 
July, 1996, which specifies procedures for replacing the propeller 
shaft, the bearings, and the front drive belt retaining rings with 
parts of improved design.
    The LBA classified this service bulletin as mandatory and issued 
German AD 96-243 DG Flugzeugbau, dated August 29, 1996, 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 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 replacing the propeller shaft, 
the bearings, and the front drive belt retaining rings with parts of 
improved design. Accomplishment of the proposed action would be in 
accordance with DG Flugzeugbau Technical Note No. 826/32, dated July 
19, 1996, and DG Flugzeugbau WORKING INSTRUCTION No. 1 for TN 826/32, 
dated July, 1996.

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 5 
workhours per glider to accomplish the proposed action, and that the 
average labor rate is approximately $60 an hour. Parts cost 
approximately $460 per glider. Based on these figures, the total cost 
impact of the proposed AD on U.S. operators is estimated to be 
$266,000, or $760 per glider.

Proposed Compliance Time

    The compliance time of the proposed AD is in calendar time instead 
of hours time-in-service (TIS). The average monthly usage of the 
affected glider ranges throughout the fleet. For example, one owner may 
operate the glider 25 hours TIS in one week, while another operator may 
operate the glider 25 hours TIS in one year. In order to ensure that 
all of the owners/operators of the affected glider have replaced the 
propeller shaft, bearings and front drive belt retaining rings within a 
reasonable amount of time, the FAA is proposing a compliance time of 4 
calendar months.

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-07-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 (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 within the next 4 calendar months after the 
effective date of this AD, unless already accomplished.
    To prevent failure of the propeller shaft, which could result in 
loss of glider propulsion during critical phases of flight, 
accomplish the following:
    (a) Replace the propeller shaft, the bearings, and the front 
drive belt retaining rings with parts of improved design in

[[Page 27872]]

accordance with paragraph 2 of the Instructions section of DG 
Flugzeugbau Technical Note No. 826/32, dated July 19, 1996, and 
WORKING INSTRUCTION No. 1 for TN 826/32, dated July, 1996.
    (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, 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 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 DG Flugzeugbau 
Technical Note No. 826/32, dated July 19, 1996, and DG Flugzeugbau 
WORKING INSTRUCTION No. 1 for TN 826/32, dated July, 1996, should be 
directed to DG Flugzeugbau GmbH, P.O. Box 4120, 76625 Bruchsal, 
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 96-243 
DG-Flugzeugbau, dated August 29, 1996.

    Issued in Kansas City, Missouri, on May 13, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-13518 Filed 5-20-98; 8:45 am]
BILLING CODE 4910-13-U