[Federal Register Volume 63, Number 180 (Thursday, September 17, 1998)]
[Proposed Rules]
[Pages 49673-49675]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-24875]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-CE-71-AD]
RIN 2120-AA64


Airworthiness Directives; Burkhart GROB Luft-und Raumfahrt GmbH 
Model G 109B 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 certain Burkhart GROB Luft-und Raumfahrt GmbH 
(Grob) Model G 109B gliders. The proposed AD would require inspecting 
the elevator and trim tab for water and to assure that the necessary 
drain holes are installed and that the existing drain holes are open. 
The proposed AD would also require drilling any necessary drain holes 
and opening any existing drain holes that are closed; and, if a 
significant amount of water (more than \1/2\ liter) is found in the 
elevator, assuring that the glider's residual momentum and center of 
gravity (C.G.) are within the limits specified in the flight manual, 
and adjusting the residual momentum and C.G., as needed. 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 water from 
penetrating the elevator and trim tab because of inadequate drainage, 
which could result in a delaminated elevator and trim tab structure 
with consequent elevator imbalance and flutter.

DATES: Comments must be received on or before October 19, 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-71-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 Burkhart Grob Luft-und Raumfahrt, D-8939 Mattsies, Germany. This 
information also may be examined at the Rules Docket at the address 
above.

FOR FURTHER INFORMATION CONTACT: Mr. Mike Kiesov, Aerospace Engineer, 
FAA, Small Airplane Directorate, 1201 Walnut, suite 900, Kansas City, 
Missouri 64106; telephone: (816) 426-6932; 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,

[[Page 49674]]

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-71-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-71-AD, Room 1558, 601 E. 12th Street, Kansas 
City, Missouri 64106.

Discussion

    The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority 
for Germany, notified the FAA that an unsafe condition may exist on 
certain Grob Model G 109B gliders. The LBA reports that the above-
referenced gliders may not have an adequate number of drain holes in 
the elevator and trim tab.
    Inadequate elevator and trim tab drainage, if not corrected in a 
timely manner, could result in water penetrating the elevator and trim 
tab. This could lead to a delaminated elevator and trim tab structure 
with consequent elevator imbalance and flutter.

Relevant Service Information

    Grob has issued Service Bulletin TM 817-35, dated July 20, 1992, 
which specifies procedures for inspecting the elevator and trim tab for 
water and to assure that the necessary drain holes are installed and 
that the existing drain holes are open. The service bulletin also 
specifies drilling any necessary drain holes and opening any existing 
drain holes that are closed; and, if a significant amount of water 
(more than \1/2\ liter) is found in the elevator, assuring that the 
glider's residual momentum and C.G., are within the limits specified in 
the flight manual, and adjusting the residual momentum and C.G., as 
needed.
    The LBA classified this service bulletin as mandatory and issued 
German AD 92-350 Grob, dated October 26, 1992, 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 Grob G 109B gliders of the same type design 
registered in the United States, the FAA is proposing AD action. The 
proposed AD would require inspecting the elevator and trim tab for 
water and to assure that the necessary drain holes are installed and 
that the existing drain holes are open. The AD would also require 
drilling any necessary drain holes and opening any existing drain holes 
that are closed; and, if a significant amount of water (more than \1/2\ 
liter) is found in the elevator, assuring that the glider's residual 
momentum and C.G. are within the limits specified in the flight manual, 
and adjusting the residual momentum and C.G, as needed. Accomplishment 
of the proposed actions would be in accordance with Grob Service 
Bulletin TM 817-35, dated July 20, 1992.

Cost Impact

    The FAA estimates that 20 gliders in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 1 
workhour per glider to accomplish the proposed inspection, and that the 
average labor rate is approximately $60 an hour. Based on these 
figures, the total cost impact of the proposed inspection on U.S. 
operators is estimated to be $1,200, or $60 per glider.
    If drain holes need to be added, the FAA estimates that it would 
take approximately 1 workhour per glider to accomplish the proposed 
modification, and that the average labor rate is approximately $60 an 
hour. Based on these figures, the total cost impact of the proposed 
modification on U.S. operators is estimated to be $60 per glider that 
would need drain holes installed.

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). The unsafe condition is 
not a result of the number of times the glider is operated. If the 
elevator and trim tab of the affected gliders have inadequate drainage, 
then water could penetrate the elevator and trim tab on the first 
flight, as well as subsequent flights. The delamination and imbalance 
that could then occur can happen in a very short period of time or 
happen over a long period of time. For these reasons, 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.

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:

[[Page 49675]]

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:

Burkhart Grob Luft-und Raumfahrt GMBH: Docket No. 98-CE-71-AD.
    Applicability: Model G 109B gliders, all serial numbers 
beginning with 6200, 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 water from penetrating the elevator and trim tab 
because of inadequate drainage, which could result in a delaminated 
elevator and trim tab structure with consequent elevator imbalance 
and sailplane flutter, accomplish the following:
    (a) Within the next 6 calendar months after the effective date 
of this AD, inspect the elevator and trim tab for water and to 
assure that the necessary drain holes are installed and that the 
existing drain holes are open. Accomplish these actions in 
accordance with the Actions section of Grob Service Bulletin TM 817-
35, dated July 20, 1992. Prior to further flight after the 
inspection, accomplish the following as specified in the service 
bulletin:
    (1) Drill any necessary drain holes and open any existing drain 
holes that are closed; and,
    (2) If a significant amount of water (more than 1/2 liter ) is 
found in the elevator, assure that the glider's residual momentum 
and center of gravity (C.G.) are within the limits specified in the 
flight manual, and adjust the residual momentum and C.G, as needed.
    (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, 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 Grob Service 
Bulletin TM 817-35, dated July 20, 1992, should be directed to 
Burkhart Grob Luft-und Raumfahrt, D-8939 Mattsies, Germany. 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 92-350 
Grob, dated October 26, 1992.

    Issued in Kansas City, Missouri, on September 9, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-24875 Filed 9-16-98; 8:45 am]
BILLING CODE 4910-13-U