[Federal Register Volume 62, Number 141 (Wednesday, July 23, 1997)]
[Rules and Regulations]
[Pages 39427-39428]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-19266]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-CE-03-AD; Amendment 39-10086; AD 97-15-12]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
applies to certain Burkhart Grob, Luft- und Raumfahrt (Grob) Model G 
109 sailplanes. This action requires 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 Model G 109 sailplanes 
that have previously accomplished this installation, a modification to 
the damper and bell crank lever, and adjustment to the weight and 
balance is required. These actions are prompted by the discovery of 
rudder vibration problems during testing of two Grob Model G 109 
sailplanes. The actions specified by this AD are intended to prevent 
vibration of the rudder, which could result in structural damage and 
eventual loss of control of the sailplane.

DATES: Effective September 19, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of September 19, 1997.

ADDRESSES: Service information that applies to this AD may be obtained 
from Burkhart Grob Luft- und Raumfahrt, D-86874 Mattsies, Germany. This 
information may also be examined at the Federal Aviation Administration 
(FAA), Central Region, Office of the Assistant Chief Counsel, 
Attention: Rules Docket 95-CE-03-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. J. Mike Kiesov, Project Officer, Sailplanes, Small Airplane 
Directorate, Aircraft Certification Service, FAA, 1201 Walnut, suite 
900, Kansas City, Missouri, 64106, telephone (816) 426-6932, and 
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 certain Grob Model G 
109 sailplanes was published in the Federal Register on August 30, 1996 
(61 FR 45912). The action proposed to 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.
    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.

Related Service Information

    Accomplishment of the proposed actions would be in accordance with 
Grob Service Bulletin (SB) TM 817-38, dated July 8, 1993, Grob SB 817-
38/2, dated March 31, 1995, Grob Installation Instructions No. 817-38/1 
for Service Bulletin 817-38/2, dated March 31, 1995, Grob Installation 
Instructions 817-38/2 for Service Bulletin/2, dated March 31, 1995.

The FAA's Determination

    After careful review of all available information related to the 
subject presented above, including the above referenced service 
information, 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.

Determination of Compliance Time

    The compliance time of this AD is in calendar time instead of hours 
time-in-service (TIS). The average monthly usage of the affected 
sailplanes ranges 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 requiring a compliance time of 6 calender months.

Cost Impact

    The FAA estimates that 34 sailplanes in the U.S. registry will be 
affected by this AD, that it will take approximately 8 workhours per 
sailplane to accomplish these actions, 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 this AD on 
U.S. operators is estimated to be $50,320. 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 these actions on their sailplanes.

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

[[Page 39428]]

``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 USC 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:

97-15-12.  Burkhart Grob, Luft-Und Raumfahrt: Amendment 39-10086; 
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 request approval for an 
alternative method of compliance in accordance with paragraph (e) 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 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 Installation Instructions No. 817-38, dated October 25, 1994, 
per Grob Service Bulletin (SB) TM 817-38, dated July 8, 1993, modify 
the damper unit and the rudder bell crank lever in accordance with 
Grob Installation Instructions No. 817-38/1, dated March 31, 1995, 
per Grob SB 817-38/2, dated March 31, 1995.
    (b) For sailplanes that have not been modified in accordance 
with Grob Installation Instructions No. 817-38, install a new damper 
unit and rudder bell crank lever in accordance with Grob 
Installation Instructions 817-38/2 dated March 31, 1995, per Grob SB 
817-38/2, dated March 31, 1995.
    (c) For all affected sailplanes, re-calculate the weight and 
balance data in accordance with the Weight and Balance 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 airplane 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, Aircraft 
Certification Service, 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) The modifications and installations required by this AD 
shall be done in accordance with GROB, Luft- und Raumfahrt GROB G 
109 Installation Instructions No. 817-38 for Service Bulletin TM 
817-38, dated October 25, 1994; GROB, Luft- und Raumfahrt GROB G 109 
Service Bulletin TM 817-38, dated July 8, 1993; GROB, Luft- und 
Raumfahrt GROB G 109 Installation Instructions No. 817-38/1 for 
Service Bulletin 817-38/2, dated March 31, 1995; GROB, Luft- und 
Raumfahrt GROB G 109 Installation Instructions No. 817-38/2 for 
Service Bulletin 817-38/2, dated March 31, 1995; and GROB, Luft- und 
Raumfahrt GROB G 109 Service Bulletin 817-38/2, dated March 31, 
1995. 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 of this document may be obtained Burkhart Grob Luft- 
und Raumfahrt, D-86874 Mattsies, Germany. Copies of this document 
may be inspected at the FAA, Central Region, Office of the Assistant 
Chief 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.
    (g) This amendment (39-10086) becomes effective on September 19, 
1997.

    Issued in Kansas City, Missouri, on July 16, 1997.
Carolanne L. Cabrini,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-19266 Filed 7-22-97; 8:45 am]
BILLING CODE 4910-13-M