[Federal Register Volume 63, Number 227 (Wednesday, November 25, 1998)]
[Rules and Regulations]
[Pages 65048-65050]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-31317]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-CE-40-AD; Amendment 39-10905; AD 98-24-20]
RIN 2120-AA64
Airworthiness Directives; Grob Luft-und Raumfahrt, GmbH Models G
109 and G 109B 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 Grob Luft-und Raumfahrt (Grob) Models G 109 and G
109B sailplanes. This AD requires inspecting the radius of the landing
gear retaining bars, installing additional supportive parts, and
replacing the retaining bars if the retaining bars' chamfer radius is
less than 3.0 millimeters (mm). This AD also requires inspecting the
landing gear legs for cracks and proper thickness, and either polishing
out the cracks or replacing the landing gear legs with parts of
improved design depending on the crack length. This AD is the result of
mandatory continuing airworthiness information (MCAI) issued by the
airworthiness authority for Germany. The actions specified by this AD
are intended to detect and correct fatigue cracking of the landing gear
legs, which could result in landing gear failure with consequent loss
of control of the sailplane during landing operations.
DATES: Effective January 9, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of January 9, 1999.
ADDRESSES: Service information that applies to this AD may be obtained
from Grob-Werke GmbH & Co. KG, Unternehmensbereich, Burkhart Grob
Flugzeugbau, Flugplatz Mattsies, 86874 Tussenhausen, Germany. This
information may also be examined at the Federal Aviation Administration
(FAA), Central Region, Office of the
[[Page 65049]]
Regional Counsel, Attention: Rules Docket No. 96-CE-40-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. 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:
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 G 109
and G 109B sailplanes was published in the Federal Register as a notice
of proposed rulemaking (NPRM) on February 19, 1997 (62 FR 7373). The
NPRM proposed to require inspecting the radius of the landing gear
retaining bars, installing additional supportive parts, and replacing
the retaining bars if the retaining bars' chamfer radius is less than
3.0 mm. The NPRM also proposed to require inspecting the landing gear
legs for cracks and proper thickness, and either polishing out the
cracks or replacing the landing gear legs with parts of improved design
depending on the crack length.
Accomplishment of the proposed action as specified in the NPRM
would be required in accordance with Grob Service Bulletin TM 817-39,
dated January 4, 1994.
The NPRM was the result of mandatory continuing airworthiness
information (MCAI) issued by the airworthiness authority for Germany.
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.
The FAA's Determination
After careful review of all available information related to the
subject presented above, 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.
Cost Impact
The FAA estimates that 63 sailplanes in the U.S. registry will be
affected by this AD.
The required inspection and modification of the retaining bars will
take approximately 4 workhours per sailplane (2 workhours per landing
gear leg) to accomplish, at an average labor rate of approximately $60
an hour. Parts to accomplish the required modifications cost $90. Based
on these figures, the total cost impact of this inspection and
modification on U.S. operators is estimated to be $20,790, or $330 per
sailplane.
The initial inspection will take approximately 18 workhours per
sailplane (9 workhours per landing gear leg) to accomplish, at an
average labor rate of $60 per hour. Based on these figures, the total
cost impact of the initial inspection on U.S. operators is estimated to
be $68,040, or $1,080 per sailplane.
The above figures only take into account the costs of the initial
inspection of the landing gear leg and do not take into account costs
associated with repetitive inspections or any required crack polishing
or landing gear leg replacement. The FAA has no way of determining the
number of repetitive inspections each owner/operator of the affected
sailplanes would incur, or the number of landing gear legs that will be
found cracked and either need polishing or replacement.
Compliance Time
The compliance time of this AD is presented in calendar time
instead of hours time-in-service (TIS). The FAA has determined that a
calendar time compliance is the most desirable method because the
unsafe condition of the landing gear legs described by this AD is
caused by corrosion. Corrosion initiates as a result of sailplane
operation, but can continue to develop regardless of whether the
sailplane is in service. In order to assure that the above-referenced
condition is detected and corrected on all sailplanes within a
reasonable period of time without inadvertently grounding any
sailplanes, the FAA is requiring a compliance schedule based upon
calendar time instead of hours TIS.
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 ``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 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:
98-24-20 Grob Luft-und Raumfahrt, GMBH: Amendment 39-10905, Docket
No. 96-CE-40-AD.
Applicability: Models G 109 and G 109B sailplanes, all serial
numbers, 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 (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.
[[Page 65050]]
Compliance: Required as indicated in the body of this AD, unless
already accomplished.
To detect and correct fatigue cracking of the landing gear legs,
which could result in landing gear failure with consequent loss of
control of the sailplane during landing operations, accomplish the
following:
(a) For all of the affected sailplanes: Within the next 120
calendar days after the effective date of this AD, inspect the
retaining bars chamfer on both landing gear legs for a minimum of
3.0 millimeters (mm) radius in accordance with the ``Actions''
section, paragraph A3, of Grob Service Bulletin (SB) 817-39, dated
January 4, 1994.
(1) If the chamfer radius is 3.0 mm or greater, prior to further
flight, glue a reinforcing plastic strip (part number (P/N) 109-
5000.07) to the retaining bar in accordance with the ``Actions''
section, paragraph A4, of Grob SB 817-39, dated January 4, 1994.
(2) If the chamfer radius is less than 3.0 mm, prior to further
flight, replace the retaining bar with a new improved design
retaining bar, P/N 109-5000.02; and install the plastic strip, P/N
109-5000.07. Accomplish these actions in accordance with the
``Actions'' section, paragraph A5, of Grob SB 817-39, dated January
1994.
(b) For sailplanes that are not equipped with landing gear legs,
P/N 109B-5001.01/1: Upon the accumulation of 1,000 hours TIS on the
landing gear leg or within the next 100 hours TIS after the
effective date of this AD, whichever occurs later, and thereafter at
intervals not to exceed 500 hours TIS, inspect the landing gear legs
for cracks (using the magnetic particle or X-ray analysis method) in
accordance with the ``Actions'' section, paragraph B9, of Grob SB
817-39, dated January 4, 1994.
(1) If any crack(s) is found that does not exceed a maximum
depth of 0.5 millimeters (mm) on each side, prior to further flight,
polish out the crack(s) in accordance with the ``Actions'' section,
paragraph B10, of Grob SB 817-39, dated January 4, 1994.
(2) If after polishing out any crack, as specified in paragraph
(b)(1) of this AD, the undercarriage thickness is not at least 13
mm, prior to further flight, replace the cracked landing gear leg
with a P/N 109B-5001.01/1 landing gear leg, in accordance with the
``Actions'' section, paragraph B10, of Grob SB 817-39, dated January
4, 1994.
(3) If any crack(s) is found that is equal to or exceeds a
maximum depth of 0.5 mm on either side, prior to further flight,
replace the cracked landing gear leg with a P/N 109B-5001.01/1
landing gear leg, in accordance with the ``Actions'' section,
paragraph B10, of Grob SB 817-39, dated January 4, 1994.
(4) Replacing both landing gear legs with P/N 109B-5001.01/1 may
be accomplished at any time as terminating action for the repetitive
inspection requirement of this AD, but must be accomplished prior to
further flight on any landing gear found cracked as specified in
paragraph (b)(2) or (b)(3) of this AD.
(5) If one landing gear leg is replaced prior to further flight
when a crack is found, the other landing gear leg must still be
repetitively inspected every 500 hours TIS until replacement with
the improved design part.
Note 2: Landing gear legs (P/N 109B-5001.01/1) have a ``0''
stamped on the front side of the leg for easy identification.
(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 sailplane 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, 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 3: 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 Grob Service
Bulletin TM 817-39, dated January 4, 1994, should be directed to
Grob-Werke GmbH & Co. KG, Unternehmensbereich, Burkhart Grob
Flugzeugbau, Flugplatz Mattsies, 86874 Tussenhausen, 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.
(f) The inspections, installation, polishing, and replacements
required by this AD shall be done in accordance to Grob Service
Bulletin TM 817-39, dated January 4, 1994. 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 may be
obtained from Grob-Werke GmbH & Co. KG, Unternehmensbereich,
Burkhart Grob Flugzeugbau, Flugplatz Mattsies, 86874 Tussenhausen,
Germany. Copies may be inspected at the FAA, Central Region, Office
of the Regional 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 becomes effective on January 9, 1999.
Issued in Kansas City, Missouri, on November 16, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-31317 Filed 11-24-98; 8:45 am]
BILLING CODE 4910-13-U
