[Federal Register Volume 60, Number 49 (Tuesday, March 14, 1995)]
[Rules and Regulations]
[Pages 13620-13621]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-5246]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-126-AD; Amendment 39-9168; AD 95-05-01]


Airworthiness Directives; British Aerospace Model BAe 146-100A, -
200A, and -300A 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 146-100A, -200A, and -
300A series airplanes, that requires conducting closed loop tests to 
determine the setting of the underfrequency trip level on suspect 
generator control units (GCU), and either the correction of 
discrepancies or replacement of the GCU. This amendment is prompted by 
several malfunctions of in-service GCU's due to the effects of setting 
the underfrequency trip level too high. The actions specified by this 
AD are intended to correct GCU's that may have the underfrequency level 
set too high, which could result in the unwanted shut down of an 
electrical generator; this condition may lead to loss of all generated 
electrical power on the airplane when other generator faults or 
failures occur.

DATES: Effective April 13, 1995. -
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of April 13, 1995.

ADDRESSES: The service information referenced in this AD may be 
obtained from British Aerospace Holdings, Inc., Avro International 
Aerospace Division, P.O. Box 16039, Dulles International Airport, 
Washington, DC 20041-6039. 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: William Schroeder, Aerospace Engineer, 
ANM-113, Standardization Branch, FAA, Transport Airplane Directorate, 
1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (206) 
227-2148; fax (206) 227-1320.

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 
146-100A, -200A, and -300A series airplanes was published in the 
Federal Register on November 16, 1994 (59 FR 59179). That action 
proposed to require checking the part and serial number on the data 
plate of each GCU to identify discrepant units, and conducting closed 
loop tests on affected GCU's to determine the setting of the 
underfrequency trip level. That action also proposed to require either 
adjusting the underfrequency trip level or replacing the discrepant GCU 
with a serviceable unit, and conducting post assembly testing. -
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the single comment received. -
    The commenter supports the proposed rule. -
    As a result of recent communications with the Air Transport 
Association (ATA) of America, the FAA has learned that, in general, 
some operators may misunderstand the legal effect of AD's on airplanes 
that are identified in the applicability provision of the AD, but that 
have been altered or repaired in the area addressed by the AD. The FAA 
points out that all airplanes identified in the applicability provision 
of an AD are legally subject to the AD. If an airplane has been altered 
or repaired in the affected area in such a way as to affect compliance 
with the AD, the owner or operator is required to obtain FAA approval 
for an alternative method of compliance with the AD, in accordance with 
the paragraph of each AD that provides for such approvals. A note has 
been added to this final rule to clarify this long-standing 
requirement. -
    After careful review of the available data, including the comment 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the change previously 
described. The FAA has determined that this change will neither 
increase the economic burden on any operator nor increase the scope of 
the AD. -
    The FAA estimates that 43 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 1 work hour per 
airplane to accomplish the required actions, and that the average labor 
rate is $60 per work hour. Based on these figures, the total cost 
impact of the AD on U.S. operators is estimated to be $2,580, or $60 
per airplane. -
    The total 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. -
    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 [[Page 13621]] ``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. 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 the following new 
airworthiness directive:

95-05-01  British Aerospace Regional Aircraft Limited, Avro 
International Aerospace Division (Formerly British Aerospace, plc; 
British Aerospace Commercial Aircraft Limited): Amendment 39-9168. 
Docket 94-NM-126-AD.

     -Applicability: All Model British Aerospace Model BAe 146-100A, 
-200A, and -300A 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 
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 use the authority 
provided in paragraph (b) to request approval from the FAA. This 
approval may address either no action, if the current configuration 
eliminates the unsafe condition; or different actions necessary to 
address the unsafe condition described in this AD. Such a request 
should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD. -
    Compliance: Required as indicated, unless accomplished 
previously. -
    To correct generator control units (GCU) that may have the 
under-frequency trip level set too high, which could lead to the 
unwanted shut down of an electrical generator, accomplish the 
following: -
    (a) Within 6 months after the effective date of this AD, check 
the part and serial number on the data plate of each generator 
control unit (GCU). If the part number is one of those affected and 
the serial number is listed in Addendum 1 of GEC-Marconi Service 
Bulletin HGE 24-23, dated March 11, 1994, prior to further flight, 
conduct a closed loop test to determine the setting of the 
underfrequency trip level, in accordance with that service 
bulletin.-
    (1) If the level exceeds that specified in GEC-Marconi Service 
Bulletin HGE 24-23, dated March 11, 1994, prior to further flight, 
adjust the level in accordance with that service bulletin; or 
replace the GCU with a serviceable unit, in accordance with Avro 
Service Bulletin S.B. 24-103, dated March 24, 1994. -
    (2) Prior to further flight, after adjustment or replacement of 
the GCU as required by paragraph (a)(1) of this AD, conduct the post 
assembly testing in accordance with Avro Service Bulletin S.B. 24-
103, dated March 24, 1994. -
    (b) 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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

     -Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    -(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 airplane to a location where 
the requirements of this AD can be accomplished. -
    (d) The closed loop test and adjustment shall be done in 
accordance with GEC-Marconi Service Bulletin HGE 24-23, dated March 
11, 1994. The replacement and post assembly test shall be done in 
accordance with Avro Service Bulletin S.B. 24-103, dated March 24, 
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 British Aerospace Holding, 
Inc., Avro International Aerospace Division, P.O. Box 16039, Dulles 
International Airport, Washington, DC 20041-6039. 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. 
-
    (e) This amendment becomes effective on April 13, 1995.

    Issued in Renton, Washington, on February 27, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-5246 Filed 3-13-95; 8:45 am]
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