[Federal Register Volume 60, Number 6 (Tuesday, January 10, 1995)]
[Proposed Rules]
[Pages 2555-2556]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-519]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-CE-30-AD]


Airworthiness Directives; B. Grob Flugzeugbau Model G109B Gliders

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This notice proposes to adopt a new airworthiness directive 
(AD) that would apply to B. Grob Flugzeugbau (Grob) Model G109B 
gliders. The proposed action would require replacing the elevator inner 
hinges with hinges of improved design. Two occurrences where the 
elevator inner hinges separated from the elevator prompted the proposed 
action. The actions specified by the proposed AD are intended to 
prevent failure of these hinges because of delamination or corrosion, 
which, if not detected and corrected, could lead to loss of control of 
the glider.

DATES: Comments must be received on or before March 14, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 94-CE-30-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 B. Grob Flugzeugbau, D-8939 Mattsies, Germany. This information 
also may be examined at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. Herman C. Belderok, Project 
Officer, Sailplanes, Small Airplane Directorate, Aircraft Certification 
Service, FAA, 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, 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. 94-CE-30-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. 94-CE-30-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    The Luftfarht-Bundesant (LBA), which is the airworthiness authority 
for Germany, recently notified the FAA that an unsafe condition may 
exist on certain Grob Model G109B gliders. The LBA reports that 
delamination and corrosion have caused the elevator inner hinges to 
separate from the elevator on two of the affected gliders. Under the 
original and current design, these hinges receive excessive stress on 
the laminated attachment point on the stabilizer and elevator, which 
causes the laminates to separate and moisture to become 
[[Page 2556]] entrapped in this area (eventual corrosion). If not 
detected and corrected, elevator inner hinge failure could lead to loss 
of control of the glider.
    Grob has issued Service Bulletin TM 817-25, dated November 9, 1987, 
which includes Repair Instructions for replacing the elevator inner 
hinges with hinges of improved design. The LBA classified this service 
bulletin as mandatory and issued LBA AD 88-50, dated March 14, 1988, in 
order to assure the continued airworthiness of these gliders in 
Germany.
    This glider model is manufactured in Germany and is type 
certificated for operation in the United States under the provisions of 
Sec. 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 Model G109B gliders of the same type 
design, the proposed AD would require replacing the elevator inner 
hinges with hinges of improved design. The proposed action would be 
accomplished in accordance with Grob Repair Instructions No. 817-25 for 
Service Bulletin TM 817-25, dated November 9, 1987.
    The unsafe condition referenced in this proposed action is caused 
by both stress loads and corrosion. Stress loads are a direct result of 
airplane usage and corrosion can occur regardless of whether the 
airplane is utilized in flight or is on the ground. With this in mind, 
the FAA has determined that the compliance time of the proposed AD 
should be in both calendar time and hours time-in-service (TIS).
    The FAA estimates that 30 gliders in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 8 
workhours per glider to accomplish the proposed action, and that the 
average labor rate is approximately $60 an hour. Parts will be provided 
by the manufacturer at no cost to the operator. Based on these figures, 
the total cost impact of the proposed AD on U.S. operators is estimated 
to be $14,400. This figure is based on the assumption that no affected 
glider owner/operator has accomplished the proposed replacement of the 
elevator inner hinges.
    Grob has informed the FAA that approximately 20 of the affected 
gliders already have the proposed replacement incorporated. With this 
in mind, the cost impact upon the public of the proposed action would 
be reduced from $14,400 to $5,280.
    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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding a new AD to read as follows:

B. Grob Flugzeugrau: Docket No. 94-CE-30-AD.

    Applicability: Model G109B gliders, serial numbers 6200 through 
6445, certificated in any category.
    Compliance: Required within the next 25 hours time-in-service 
after the effective date of this AD or the next 6 calendar months 
after the effective date of this AD, whichever occurs first, unless 
already accomplished.
    To prevent failure of the elevator inner hinges because of 
delamination or corrosion, which, if not detected and corrected, 
could lead to loss of control of the glider, accomplish the 
following:
    (a) Replace the elevator inner hinges (2) with hinges of 
improved design, part number 109B-3550, in accordance with Grob 
Repair Instructions No. 817-25 for Service Bulletin TM 817-25, dated 
November 9, 1987.

    Note: The service instructions of this AD call for ``the 
execution of the instructions to be certified in the log-book by an 
authorized inspector class 3.'' This type of inspector is not 
applicable in the United States and the person accomplishing the AD 
is as outlined in part 43 of the Federal Aviation Regulations (14 
CFR part 43). This is not a change over normal AD procedures.

    (b) 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 gliders 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, FAA, 1201 
Walnut, suite 900, Kansas City, Missouri 64106. The request should 
be forwarded through an appropriate FAA Maintenance Inspector, who 
may add comments and then send it to the Manager, Small Airplane 
Directorate.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Small Airplane Directorate.

    (d) All persons affected by this directive may obtain copies of 
the document referred to herein upon request to B. Grob Flugzeugbau, 
D-8939 Mattsies, Germany; or may examine this document 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 January 4, 1995.

Henry A. Armstrong,

Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.

[FR Doc. 95-519 Filed 1-9-95; 8:45 am]

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