[Federal Register Volume 63, Number 62 (Wednesday, April 1, 1998)]
[Proposed Rules]
[Pages 15793-15795]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8463]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-CE-133-AD]
RIN 2120-AA64


Airworthiness Directives; Glaser-Dirks Flugzeugbau GmbH Models 
DG-100 and 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) Models DG-100 and DG-400 gliders. The proposed AD would require 
repetitively inspecting the airbrakes to assure they retract at their 
outboard end first, and repairing the airbrakes if they do not retract 
at their outboard end first; and repetitively inspecting the airbrake 
torque tube in the fuselage for cracks or deformations, and reinforcing 
or replacing, as necessary, if cracks or deformations are found in the 
airbrake torque tube. 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 overloading of the airbrake control system caused 
by free play between the bellcrank and airbrake plate, which could 
result in failure of the operating lever of the airbrake torque tube in 
the fuselage.

DATES: Comments must be received on or before May 8, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 97-CE-133-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. 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. 97-CE-133-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. 97-CE-133-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 DG-Flugzeugbau Models DG-100 and DG-400 gliders. The LBA 
reports two weld joint failures of the airbrake torque tube and 
incidents of free play between the bellcrank and airbrake plate. This 
freeplay could prevent the airbrake cap from being flush with the wing 
surface at the outboard wing at the outboard end.
    These conditions, if not corrected in a timely manner, could result 
in overloading of the airbrake control

[[Page 15794]]

system and failure of the operating lever of the airbrake torque tube 
in the fuselage.

Relevant Service Information

    Glaser-Dirks has issued DG-Flugzeugbau Technical Note No. 301/18, 
No. 323/9, and No. 826/34, dated November 4, 1996, which specifies 
inspecting the airbrakes to assure they retract at their outboard end 
first, and repairing the airbrakes if they do not retract at their 
outboard end first; and repetitively inspecting the airbrake torque 
tube in the fuselage for cracks or deformations, and reinforcing or 
replacing, as necessary, if cracks or deformations are found in the 
airbrake torque tube. The procedures for accomplishing these actions 
are included in the following:
     DG-Flugzeugbau GmbH Working instructions No. 1 for 
Technical Note No. 301/18, 323/9, and 826/34, dated November 4, 1996, 
for the airbrake retraction inspection and repair; and
     DG-Flugzeugbau GmbH Working instructions No. 2 for 
Technical Note No. 301/18, 323/9, and 826/34, dated November 4, 1996, 
for the airbrake torque tube inspection and reinforcement or 
replacement.
    The LBA classified this service information as mandatory and issued 
German AD 97-011, dated January 30, 1997, 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 Models DG-100 and DG-400 gliders 
of the same type design registered in the United States, the FAA is 
proposing AD action. The proposed AD would require repetitively 
inspecting the airbrakes to assure they retract at their outboard end 
first, and repairing the airbrakes if they do not retract at their 
outboard end first; and repetitively inspecting the airbrake torque 
tube in the fuselage for cracks or deformations, and reinforcing or 
replacing, as necessary, if cracks or deformations are found in the 
airbrake torque tube. Accomplishment of the proposed installation would 
be required in accordance with the service information previously 
referenced.

Compliance Time of the Proposed AD

    Although the problems identified with the airbrake control system 
would only be unsafe during flight, this 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 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 45 gliders in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 4 
workhours per glider to accomplish the proposed inspections, and that 
the average labor rate is approximately $60 an hour. Based on these 
figures, the total cost impact of the proposed AD on U.S. operators is 
estimated to be $10,800, or $240 per glider.
    These figures are based only on the initial inspections and do not 
take into account the costs of any repetitive inspections or 
reinforcements and modifications that would be needed based on the 
results of the proposed inspections. The FAA has no way of determining 
the number of repetitive inspections each owner/operator of the 
affected airplanes would incur, or the number of airbrake control 
systems that would require modification, reinforcement, or repair.

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. 97-CE-133-AD.

    Applicability: Models DG-100 and 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 overloading of the airbrake control system caused by 
free play between the bellcrank and airbrake plate, which could 
result in failure of the operating lever of the

[[Page 15795]]

airbrake torque tube in the fuselage, accomplish the following:
    (a) Within the next 3 calendar months after the effective date 
of this AD, and thereafter at intervals not to exceed 12 calendar 
months, inspect the airbrakes to assure they retract at their 
outboard end first in accordance with DG-Flugzeugbau GmbH Working 
instructions No. 1 for Technical Note No. 301/18, 323/9, and 826/34, 
dated November 4, 1996. If the airbrakes do not retract at their 
outboard end first, prior to further flight, repair the airbrakes in 
accordance with the above-referenced working instructions.
    (b) Within the next 30 calendar days after the effective date of 
this AD, and thereafter at intervals not to exceed 12 calendar 
months, inspect the airbrake torque tube in the fuselage for cracks 
or deformations in accordance with DG-Flugzeugbau GmbH Working 
instructions No. 2 for Technical Note No. 301/18, 323/9, and 826/34, 
dated November 4, 1996. If cracks or deformations are found in the 
airbrake torque tube, prior to further flight, reinforce or replace, 
as necessary, in accordance with the above-referenced working 
instructions.
    (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 
initial or repetitive 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 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 service 
information referenced in this AD 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 97-011, 
dated January 30, 1997.

    Issued in Kansas City, Missouri, on March 24, 1998.
Carolanne L. Cabrini,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-8463 Filed 3-31-98; 8:45 am]
BILLING CODE 4910-13-U