[Federal Register Volume 62, Number 246 (Tuesday, December 23, 1997)]
[Rules and Regulations]
[Pages 66980-66982]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-33509]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-283-AD; Amendment 39-10262; AD 97-26-19]
RIN 2120-AA64
Airworthiness Directives; Aerospatiale Model ATR42-300 and ATR42-
320 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
-----------------------------------------------------------------------
SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to all Aerospatiale Model ATR42-300 and ATR42-320
series airplanes, that currently requires repetitive ultrasonic
inspections to detect fatigue cracks of the lower lugs of the barrel of
the main landing gear (MLG); and replacement of cracked lower lugs with
new or serviceable parts, and a follow-on inspection. This amendment
expands the applicability of the existing AD. This action also provides
for an optional terminating action, which, if accomplished, terminates
the repetitive inspection requirement. This amendment is prompted by
issuance of mandatory continuing airworthiness information by a foreign
civil airworthiness authority. The actions specified in this AD are
intended to detect and correct fatigue cracking of the lower lugs of
the barrel of the MLG, which could lead to the collapse of the MLG.
DATES: Effective January 7, 1998.
The incorporation by reference of Messier-Dowty Service Bulletin
631-32-133, dated February 24, 1997, as revised by Messier-Dowty
Service Bulletin Change Notice No. 1, dated March 18, 1997, as listed
in the regulations, is approved by the Director of the Federal Register
as of January 7, 1998.
The incorporation by reference of Messier-Dowty Service Bulletin
631-32-132, dated January 21, 1997, as listed in the regulations, was
approved previously by the Director of the Federal Register as of March
7, 1997 (62 FR 7665, February 20, 1997).
Comments for inclusion in the Rules Docket must be received on or
before January 22, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 97-NM-283-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056.
The service information referenced in this AD may be obtained from
Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex 03, France.
This information may be examined at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the
Office of the Federal Register, 800 North Capitol Street, NW., suite
700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: International Branch, ANM-116, FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.
SUPPLEMENTARY INFORMATION: On February 10, 1997, the FAA issued AD 97-
04-09, amendment 39-9933 (62 FR 7665, February 20, 1997), which is
applicable to certain Aerospatiale Model ATR42-300 and ATR42-320 series
airplanes. That AD requires repetitive ultrasonic inspections to detect
fatigue cracks of the lower lugs of the barrel of the main landing gear
(MLG), for airplanes on which the barrel assembly has been overhauled
or repaired. If any lower lug is found to be cracked, the AD further
requires replacement of the MLG barrel assembly with new or serviceable
parts, and a follow-on inspection. That action was prompted by reports
indicating that, due to fatigue cracking in the lower lugs of the
barrel, the MLG collapsed. The actions required by that AD are intended
to detect and correct such fatigue cracking, which could lead to the
collapse of the MLG.
Actions Since Issuance of Previous Rule
Since the issuance of that AD, the Direction Generale de l'Aviation
Civile (DGAC), which is the airworthiness authority for France, advises
that further investigation has revealed that the fatigue cracking is
the result of a design flaw that may also affect new barrel assemblies
that have never been overhauled or repaired. In addition, the DGAC
advises that the interval for the repetitive inspections may be
extended from 700 landings to 900 landings.
Relevant Service Information
Messier-Dowty has issued Service Bulletin 631-32-133, dated
February 24, 1997, which describes procedures to modify the lower lugs
of the barrel of the MLG. The modification entails reconditioning the
lower lugs and installing new bushings on the swinging lever.
Accomplishment of this modification will prevent failure of the lugs
due to fatigue cracking. Accomplishment of the modification
[[Page 66981]]
eliminates the need for the repetitive visual inspections. The DGAC
classified this service bulletin as mandatory, and issued French
airworthiness directive 96-294(B)R1, dated September 10, 1997, in order
to assure the continued airworthiness of these airplanes in France.
FAA's Conclusions
This airplane model is manufactured in France 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 DGAC has kept the FAA informed
of the situation described above. The FAA has examined the findings of
the DGAC, 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.
Explanation of Requirements of Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design registered
in the United States, this AD supersedes AD 97-04-09 to continue to
require repetitive ultrasonic inspections to detect fatigue cracks of
the lower lugs of the barrel of the main landing gear (MLG); and
replacement of cracked lower lugs with new or serviceable parts, and a
follow-on inspection. This AD expands the applicability of the existing
AD to include all Model ATR42-300 and -320 series airplanes, regardless
of whether the MLG barrel assemblies installed on those airplanes are
new, overhauled, or repaired. Additionally, this AD extends the
repetitive inspection interval from 700 to 900 landings.
This AD also provides for optional modification of the lower lugs
of the barrel of the MLG, which, if accomplished, constitutes
terminating action for the repetitive inspection requirements of this
AD. The modification is required to be accomplished in accordance with
the service bulletin described previously.
Interim Action
This is considered to be interim action. The FAA is currently
considering requiring the modification of the lower lugs of the barrel
of the MLG. However, the planned compliance time for the installation
of the modification is sufficiently long so that prior notice and time
for public comment will be practicable.
Determination of Rule's Effective Date
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this rule by
submitting such written data, views, or arguments as they may desire.
Communications shall identify the Rules Docket number and be submitted
in triplicate to the address specified under the caption ADDRESSES. All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD action and determining whether additional rulemaking action would be
needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the 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
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 97-NM-283-AD.'' The postcard will be date stamped and
returned to the commenter.
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.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and that it is not a ``significant regulatory
action'' under Executive Order 12866. It has been determined further
that this action involves an emergency regulation under DOT Regulatory
Policies and Procedures (44 FR 11034, February 26, 1979). If it is
determined that this emergency regulation otherwise would be
significant under DOT Regulatory Policies and Procedures, a final
regulatory evaluation will be prepared and placed in the Rules Docket.
A copy of it, if filed, may be obtained from 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 removing amendment 39-9933 (62 FR
7665, February 20, 1997), and by adding a new airworthiness directive
(AD), amendment 39-, to read as follows:
97-26-19 Aerospatiale: Amendment 39-10262. Docket 97-NM-283-AD.
Supersedes AD 97-04-09, Amendment 39-9933.
Applicability: All Model ATR42-300 and ATR42-320 series
airplanes, certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes 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.
[[Page 66982]]
Compliance: Required as indicated, unless accomplished
previously.
To detect and correct fatigue cracking in the lower lugs of the
barrel of the main landing gear (MLG), and consequent collapse of
the MLG, accomplish the following:
(a) Perform an ultrasonic inspection to detect fatigue cracks of
the lower lugs of the barrel of the MLG, in accordance with Messier-
Dowty Service Bulletin 631-32-132, dated January 21, 1997, at the
time specified in paragraph (a)(1) or (a)(2) of this AD, as
applicable:
(1) Within 2 years after the last overhaul or repair of the
lower lugs of the barrel of the MLG, or within 60 days after March
7, 1997 (the effective date of AD 97-04-09, amendment 39-9933),
whichever occurs later; or
(2) Within 5 years after the installation of a new MLG barrel
assembly, or within 60 days after the effective date of this AD,
whichever occurs later.
(b) If, during any inspection required by this AD, no echo is
detected, or if the echo is less than 20%, repeat the ultrasonic
inspection thereafter at intervals not to exceed 900 landings.
(c) If, during any inspection required by this AD, the echo is
greater than or equal to 20%, prior to further flight, replace the
MLG barrel assembly with a new or serviceable MLG barrel assembly,
in accordance with the service bulletin.
(1) If the damaged barrel assembly is replaced with an
overhauled or repaired assembly, within 2 years after installation
of that overhauled or repaired part, accomplish the actions
specified in paragraph (a) of this AD.
(2) If the damaged barrel assembly is replaced with a new barrel
assembly, within 5 years after installation of that new part,
accomplish the actions specified in paragraph (a) of this AD.
(d) Modification of the lower lugs of the barrel of the MLG in
accordance with Messier-Dowty Service Bulletin 631-32-133, dated
February 24, 1997, as revised by Messier-Dowty Service Bulletin
Change Notice No. 1, dated March 18, 1997, constitutes terminating
action for the repetitive inspection requirements of this AD.
(e) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, International Branch, ANM-116, FAA,
Transport Airplane Directorate. Operators shall submit their
requests through an appropriate FAA Principal Maintenance Inspector,
who may add comments and then send it to the Manager, International
Branch, ANM-116.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
(f) 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.
(g) The actions shall be done in accordance with Messier-Dowty
Service Bulletin 631-32-133, dated February 24, 1997, as revised by
Messier-Dowty Service Bulletin Change Notice No. 1, dated March 18,
1997; and Messier-Dowty Service Bulletin 631-32-132, dated January
21, 1997.
(1) The incorporation by reference of Messier-Dowty Service
Bulletin 631-32-133, dated February 24, 1997, as revised by Messier-
Dowty Service Bulletin Change Notice No. 1, dated March 18, 1997, is
approved by the Director of the Federal Register in accordance with
5 U.S.C. 552(a) and 1 CFR part 51.
(2) The incorporation by reference of Messier-Dowty Service
Bulletin 631-32-132, dated January 21, 1997, was approved previously
by the Director of the Federal Register as of March 7, 1997 (62 FR
7665, February 20, 1997).
(3) Copies may be obtained from Aerospatiale, 316 Route de
Bayonne, 31060 Toulouse, Cedex 03, France. Copies may be inspected
at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW.,
Renton, Washington; or at the Office of the Federal Register, 800
North Capitol Street, NW., suite 700, Washington, DC.
Note 3: The subject of this AD is addressed in French
airworthiness directive 96-294(B)R1, dated September 10, 1997.
(h) This amendment becomes effective on January 7, 1998.
Issued in Renton, Washington, on December 15, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-33509 Filed 12-22-97; 8:45 am]
BILLING CODE 4910-13-U