[Federal Register Volume 64, Number 248 (Tuesday, December 28, 1999)]
[Rules and Regulations]
[Pages 72522-72524]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-31676]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-331-AD; Amendment 39-11454; AD 99-25-11]
RIN 2120-AA64


Airworthiness Directives; British Aerospace Model BAe 146 and 
Avro 146-RJ Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all British Aerospace Model BAe 146 series airplanes and 
certain British Aerospace Model Avro 146-RJ series airplanes, that 
requires repetitive eddy current inspections to detect fatigue cracking 
along the face of the retraction attachment boss in the nose landing 
gear sidewall; and corrective action, if necessary. This amendment is 
prompted by issuance of mandatory continuing airworthiness information 
by a foreign civil aviation authority. The actions specified by this AD 
are intended to detect and correct fatigue cracking along the face of 
the retraction attachment boss in the nose landing gear sidewall, which 
could result in premature extension of the nose landing gear or 
depressurization of the airplane.

DATES: Effective February 1, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 1, 2000.

ADDRESSES: The service information referenced in this AD may be 
obtained from British Aerospace Regional Aircraft American Support, 
13850 Mclearen Road, Herndon, Virginia 20171. This information may be 
examined at the Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 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: Norman B. Martenson, Manager, 
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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to all British Aerospace Model BAe 
146 series airplanes and certain British Aerospace Model Avro 146-RJ 
series airplanes was published in the Federal Register on June 28, 1999 
(64 FR 34586). That action proposed to require repetitive eddy current 
inspections to detect fatigue cracking along the face of the retraction 
attachment boss in the nose landing gear sidewall; and corrective 
action, if necessary.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Request To Change the Statement of Unsafe Condition

    One commenter states that the description of the unsafe condition, 
as stated in the notice of proposed rulemaking (NPRM), is incorrect. 
The commenter requests that, instead of stating ``such fatigue 
cracking, if not corrected, could result in failure of the nose landing 
gear during take-off and landing,'' the consequence of such fatigue 
cracking should be stated as ``premature extension of the nose landing 
gear and/or * * * a depressurization of the aircraft.''
    The FAA concurs with the commenter's request. Therefore, the 
statement of unsafe condition has been revised in the summary and the 
body of the final rule to correctly state the unsafe condition.

Request To Allow Contact of Manufacturer if Cracks Are Found

    One commenter requests that the final rule be revised to state, 
``If cracks are found, before further flight[,] either[;]

[[Page 72523]]

contact BAe Customer Support for further advice or repair in accordance 
with a method approved by the FAA.'' The commenter states that the 
proposed requirement for repair prior to further flight in accordance 
with a method approved by the FAA or Civil Aviation Authority (CAA), is 
too restrictive and could force operators to ground airplanes with 
cracks along the face of the retraction attachment boss in the nose 
landing gear sidewall, regardless of crack length. The commenter states 
that it has demonstrated by test that ultimate loads can be sustained 
if a crack has extended to the edge of the retraction attachment boss.
    The FAA does not concur with the commenter's request. To require 
operators to contact the manufacturer for repair instructions, as 
suggested by the commenter, would be delegating the FAA's rulemaking 
authority to the manufacturer. In addition, because specific repair 
instructions were not included in the referenced service bulletin and 
have not been provided to the FAA by the manufacturer, the FAA cannot 
include specific repair instructions in the final rule. Also, although 
the manufacturer has advised that it plans to revise the service 
bulletin to include repair instructions, the FAA does not consider it 
appropriate to delay issuance of the final rule while awaiting the 
revised service bulletin.
    However, the FAA recognizes that the requirement to repair any 
crack prior to further flight, regardless of the length of the crack, 
could be, in this case, unnecessarily restrictive. As stated by the 
commenter, tests have shown that cracked structure within defined 
limits can sustain limit loads without failure. Thus, the FAA finds 
that a stringent repetitive inspection program, acceptable to the FAA 
or CAA, may provide an acceptable level of safety that would allow for 
deferment of a permanent repair for a certain period of time. Because 
the manufacturer has not provided the FAA with such a repetitive 
inspection program nor criteria to allow a temporary deferral of 
permanent repair, such instructions cannot be included in the final 
rule. However, to allow for the possibility of a temporary deferral of 
repair, paragraph (b) of this final rule has been revised to require, 
if any crack is detected, repair or reinspection prior to further 
flight in accordance with a method approved by the FAA or CAA.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    The FAA estimates that 44 airplanes of U.S. registry will be 
affected by this required AD, that it will take approximately 1 work 
hour per airplane to accomplish the required inspection, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the required AD on U.S. operators is estimated to be 
$2,640, or $60 per airplane, per inspection cycle.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the requirements of this AD 
action, and that no operator would accomplish those actions in the 
future if this AD were not adopted.

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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it 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 adding the following new 
airworthiness directive:
99-25-11 British Aerospace Regional Aircraft (Formerly British 
Aerospace Regional Aircraft Limited, Avro International Aerospace 
Division; British Aerospace, PLC; British Aerospace Commercial 
Aircraft Limited): Amendment 39-11454. Docket 98-NM-331-AD.

    Applicability: Model BAe 146 and Avro 146-RJ series airplanes, 
as listed in British Aerospace Service Bulletin SB.53-152, dated 
October 8, 1998, certificated in any category.

    Note 1: This AD applies to each airplane 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 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 (c) 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 as indicated, unless accomplished 
previously.
    To detect and correct fatigue cracking along the face of the 
retraction attachment boss in the nose landing gear sidewall, which 
could result in premature extension of the nose landing gear or 
result in depressurization of the airplane, accomplish the 
following:

Repetitive Inspections

    (a) Prior to the accumulation of 8,000 total flight cycles, or 
within 200 flight cycles after the effective date of this AD, 
whichever occurs later, perform an eddy current inspection to detect 
cracking along the face of the retraction attachment boss in the 
nose landing gear sidewall, in accordance with British Aerospace 
Service Bulletin SB.53-152, dated October 8, 1998. Thereafter, 
repeat the eddy current inspection at intervals not to exceed 2,600 
flight cycles.

Repair

    (b) If any crack is detected, prior to further flight, repair or 
reinspect in accordance with a method approved by either the 
Manager, International Branch, ANM-116, FAA, Transport Airplane 
Directorate; or the Civil Aviation Authority (or its delegated 
agent). For a repair method to be approved by the Manager, 
International Branch, ANM-116, as

[[Page 72524]]

required by this paragraph, the Manager's approval letter must 
specifically reference this AD.

Alternative Methods of Compliance

    (c) 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. 
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.

Special Flight Permits

    (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.

Incorporation by Reference

    (e) The inspections shall be done in accordance with British 
Aerospace Service Bulletin SB.53-152, dated October 8, 1998. 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 British Aerospace Regional Aircraft 
American Support, 13850 Mclearen Road, Herndon, Virginia 20171. 
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 British 
airworthiness directive 015-10-98.

(f) This amendment becomes effective on February 1, 2000.

    Issued in Renton, Washington, on December 1, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-31676 Filed 12-27-99; 8:45 am]
BILLING CODE 4910-13-U