AD Amdt-39-10561
Unsafe Condition
Rudder vibrations caused by flow separation at the rudder gap could result in flutter with consequent loss of rudder control.
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Required Actions
Install a rudder gap seal and modify the cooling liquid reservoir mount.
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Compliance Time
Before further flight
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Affected Aircraft
Glaser-Dirks Flugzeugbau GmbH Model DG-500M gliders
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
This amendment adopts a new airworthiness directive (AD) that applies to all Glaser-Dirks Flugzeugbau GmbH (Glaser-Dirks) Model DG- 500M gliders. This AD requires installing a rudder gap seal and modifying the cooling liquid reservoir mount. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Germany. The actions specified by this AD are intended to prevent rudder vibrations caused by flow separation at the rudder gap, which could result in flutter with consequent loss of rudder control.
Document Text
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[Federal Register Volume 63, Number 107 (Thursday, June 4, 1998)]
[Rules and Regulations]
[Pages 30372-30373]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 98-14618]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-CE-09-AD; Amendment 39-10561; AD 98-12-04]
RIN 2120-AA64
Airworthiness Directives; Glaser-Dirks Flugzeugbau GmbH Model DG-
500M Gliders
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
applies to all Glaser-Dirks Flugzeugbau GmbH (Glaser-Dirks) Model DG-
500M gliders. This AD requires installing a rudder gap seal and
modifying the cooling liquid reservoir mount. This AD is the result of
mandatory continuing airworthiness information (MCAI) issued by the
airworthiness authority for Germany. The actions specified by this AD
are intended to prevent rudder vibrations caused by flow separation at
the rudder gap, which could result in flutter with consequent loss of
rudder control.
DATES: Effective July 21, 1998.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of July 21, 1998.
ADDRESSES: Service information that applies to this 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
may also be examined at the Federal Aviation Administration (FAA),
Central Region, Office of the Regional Counsel, Attention: Rules Docket
No. 98-CE-09-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.
FOR FURTHER INFORMATION CONTACT: Mr. 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:
Events Leading to the Issuance of This AD
A proposal to amend part 39 of the Federal Aviation Regulations (14
CFR part 39) to include an AD that would apply to all Glaser-Dirks
Model DG-500M gliders was published in the Federal Register as a notice
of proposed rulemaking (NPRM) on March 20, 1998 (63 FR 13581). The NPRM
proposed to require installing a rudder gap seal and modifying the
cooling liquid reservoir mount. Accomplishment of the proposed
installation as specified in the NPRM would be required in accordance
with the maintenance manual. Accomplishment of the proposed
modification to the cooling liquid reservoir mount as specified in the
NPRM would be required in accordance with Glaser-Dirks Working
Instruction No. 1 for TN 843/5, dated November 5, 1992, as referenced
in Glaser-Dirks TN No. 843/5, dated November 30, 1992.
The NPRM was the result of mandatory continuing airworthiness
information (MCAI) issued by the airworthiness authority for Germany.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. No comments were received on the
proposed rule or the FAA's determination of the cost to the public.
The FAA's Determination
After careful review of all available information related to the
subject presented above, the FAA has determined that air safety and the
public interest require the adoption of the rule as proposed except for
minor editorial corrections. The FAA has determined that these minor
corrections will not change the meaning of the AD and will not add any
additional burden upon the public than was already proposed.
Compliance Time of This AD
Although the rudder vibrations identified in this AD occur during
flight, this unsafe condition is not a result of the number of times
the glider is operated. The chance of this situation occurring is the
same for a glider with 10 hours time-in-service (TIS) as it is for a
glider with 500 hours TIS. For this reason, 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.
Cost Impact
The FAA estimates that 5 gliders in the U.S. registry will be
affected by this AD, that it will take approximately 4 workhours per
glider to accomplish this action, and that the average labor rate is
approximately $60 an hour. Parts cost approximately $40 per glider.
Based on these figures, the total cost impact of
[[Page 30373]]
this AD on U.S. operators is estimated to be $1,400, or $280 per
glider.
Regulatory Impact
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 copy of the final evaluation prepared for this
action is contained 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, Incorporation by
reference, 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 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:
98-12-04 Glaser-Dirks Flugzeugbau GmbH: Amendment 39-10561; Docket
No. 98-CE-09-AD.
Applicability: Model DG-500M 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 within the next 3 calendar months after the
effective date of this AD, unless already accomplished.
To prevent rudder vibrations caused by flow separation at the
rudder gap, which could result in flutter with consequent loss of
rudder control, accomplish the following:
(a) Install a rudder gap seal in accordance with the
instructions in the maintenance manual, as referenced in Glaser-
Dirks Technical Note (TN) No. 843/5, dated November 30, 1992.
(b) Modify the cooling liquid reservoir mount in accordance with
Glaser-Dirks Working Instruction No. 1 for TN 843/5, dated November
5, 1992, as referenced in Glaser-Dirks TN No. 843/5, dated November
30, 1992.
(c) Special flight permits may be issued in accordance with
Secs. 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 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.
(e) Questions or technical information related to Glaser-Dirks
Technical Note No. 843/5, dated November 30, 1992, 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.
(f) The modification required by this AD shall be done in
accordance with Glaser-Dirks Working Instruction No. 1 for Technical
Note 843/5, dated November 5, 1992, as referenced in Glaser-Dirks
Technical Note No. 843/5, dated November 30, 1992. This
incorporation by reference was approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. Copies may be obtained from DG Flugzeugbau GmbH, Postfach 4120,
D-76625 Bruchsal 4, Germany. Copies may be inspected at the FAA,
Central Region, Office of the Regional Counsel, Room 1558, 601 E.
12th Street, Kansas City, Missouri, or at the Office of the Federal
Register, 800 North Capitol Street, NW, suite 700, Washington, DC.
Note 3: The subject of this AD is addressed in German AD 93-010,
dated January 5, 1993.
(g) This amendment becomes effective on July 21, 1998.
Issued in Kansas City, Missouri, on May 26, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-14618 Filed 6-3-98; 8:45 am]
BILLING CODE 4910-13-U
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