[Federal Register Volume 61, Number 170 (Friday, August 30, 1996)]
[Proposed Rules]
[Pages 45912-45914]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-22248]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-CE-03-AD]
RIN 2120-AA64


Airworthiness Directives; Burkhart Grob, Luft- und Raumfahrt, 
Model G 109 Sailplanes

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 the Burkhart Grob, Luft-und Raumfahrt (Grob) 
Model G 109 sailplanes. The proposed action would require installing a 
damper and new bell crank lever on the rudder, in addition to adjusting 
the weight and balance of the sailplane, to correct the tendency of 
flutter at specific excitation frequencies. For those Grob G 109 
airplanes that have previously accomplished this installation, a 
proposed modification to the damper and bell crank lever, and adjusting 
the weight and balance would be required. The proposed action is 
prompted by the discovery of rudder vibration problems during testing 
of two Model G 109 sailplanes. The actions specified by the proposed AD 
are intended to prevent the oscillation of the rudder, which could 
result in structural damage and eventual loss of control of the 
sailplane.

DATES: Comments must be received on or before November 1, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 95-CE-03-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 Burkhard Grob Luft-und Raumfahrt, D-86874 Mattsies, Germany. 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.

[[Page 45913]]

    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. 95-CE-03-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 Assistant Chief Counsel, 
Attention: Rules Docket No. 95-CE-03-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 certain Grob Model G 109 sailplanes. The LBA reports that the 
rudder has a tendency to vibrate, which if not detected and corrected, 
will cause structural damage and eventual loss of control of the 
sailplane.
    Burkhart Grob issued Service Bulletin (SB) TM 817-38, dated July 8, 
1993, and Installation Instructions 817-38, dated October 25, 1994, 
which specify installation of a rudder damper and a new bell crank 
lever in the rudder control system. Subsequently, Burkhart Grob issued 
SB 817-38/2, dated March 31, 1995, to correct minor tolerance 
difficulties with the damper installation. This revised SB references 
two sets of installation instructions. Grob Installation Instructions 
No. 817-38/1, dated March 31, 1995, applies to Grob G 109 sailplanes 
that have been modified in accordance with the previous version of the 
SB and Installation Instructions. Grob Installation Instructions No. 
817-38/2, dated March 31, 1995, applies to those Grob G 109 sailplanes 
that have not been so modified.
    This sailplane 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, and determined that AD action 
is necessary for products of this type design that are certificated for 
operation in the United States.
    Since an unsafe condition has been identified that is likely to 
exist or develop in other Grob G 109 sailplanes of the same type 
design, the proposed AD would require installing a rudder damper and a 
new rudder bell crank lever in the controls and adjusting the weight 
and balance; or modifying the rudder damper and bell crank lever, in 
addition to adjusting the weight and balance of the sailplane. 
Accomplishment of the proposed action would be in accordance with Grob 
SB 817-38/2, dated March 31, 1995, and either Grob Installation 
Instructions No. 817-38/1 or Grob Installation Instructions No. 817-38/
2, both dated March 31, 1995, whichever is applicable.
    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 sailplanes varies throughout the fleet. For example, one owner 
may operate the sailplane 25 hours TIS in one week, while another 
operator may operate the sailplane 25 hours TIS in one year. In order 
to ensure that all of the affected sailplanes have a rudder damper and 
a new rudder bell crank lever installed within a reasonable amount of 
time, the FAA is proposing a compliance time of 6 calendar months.
    The FAA estimates that 23 sailplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 8 hours 
per sailplane to accomplish the proposed action, and that the average 
labor rate is approximately $60 an hour. Parts cost approximately 
$1,000 per sailplane. Based on these figures, the total cost impact of 
the proposed AD on U.S. operators is estimated to be $34,040. Grob has 
informed the FAA that no parts have been distributed to equip any 
sailplane in the United States. The FAA has no way of determining how 
many owners/operators may have incorporated the proposed actions on 
their sailplane.
    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, 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 AD to read as follows:

    Burkhart Grob, Luft- und Raumfahrt: Docket No. 95-CE-03-AD.

    Applicability: Model G 109 sailplanes (serial numbers 6001 
through 6159), certificated in any category.

    Note 1: This AD applies to each sailplane 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 sailplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must use the authority 
provided in paragraph (e) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition, or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any aircraft from the applicability of this AD.
    Compliance: Required within the next 6 calendar months after the 
effective date of this AD, unless already accomplished.
    To prevent vibration of the rudder, which could result in 
structural damage and eventual loss of control of the sailplane, 
accomplish the following:
    (a) For sailplanes that have been modified in accordance with 
Grob Service Bulletin (SB) TM 817-38, dated July 8, 1993, and

[[Page 45914]]

Grob Installation Instructions No. 817-38, dated October 25, 1994, 
modify the damper unit and the rudder bell crank lever in accordance 
with Grob SB 817-38/2, dated March 31, 1995, and Grob Installation 
Instructions No. 817-38/1, dated March 31, 1995.
    (b) For sailplanes that have not been modified in accordance 
with Grob SB TM 817-38, dated July 8, 1993, and Grob Installation 
Instructions No. 817-38, dated October 25, 1994, install a new 
damper unit and rudder bell crank lever in accordance with Grob SB 
817-38/2, dated March 31, 1995 and Grob Installation Instructions 
No. 817-38/2 dated March 31, 1995.
    (c) For all affected sailplanes, re-calculate the weight and 
balance data in accordance with the Actions section in Grob SB 817-
38/2, dated March 31, 1995.
    (d) 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 sailplane to a location where 
the requirements of this AD can be accomplished.
    (e) 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.

    (f) All persons affected by this directive may obtain copies of 
the documents referred to herein upon request to Burkhard Grob Luft 
-und Raumfahrt, D-86874 Mattsies, Germany; or may examine these 
documents at the FAA, Central Region, Office of the Assistant Chief 
Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

    Issued in Kansas City, Missouri, on August 23, 1996.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 96-22248 Filed 8-29-96; 8:45 am]
BILLING CODE 4910-13-U