[Federal Register Volume 61, Number 221 (Thursday, November 14, 1996)]
[Rules and Regulations]
[Pages 58326-58327]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-28871]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-40-AD; Amendment 39-9813; AD 96-23-08]
RIN 2120-AA64
Airworthiness Directives; British Aerospace Model BAe 146 Series
Airplanes and Model 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 certain British Aerospace Model BAe 146 and Model Avro
146-RJ series airplanes, that requires repetitive tests of the
integrity of the electrical circuit between the windshear computer and
the flap position sensor, and repair of the electrical wiring, if
necessary. This amendment also requires replacement of certain
windshear computers with new computers, which, when accomplished,
terminates the repetitive tests. This amendment is prompted by a report
indicating that the existing windshear computer is not capable of
detecting a signal indicating loss of flap position; this could result
in the flightcrew following erroneous computer-generated guidance. The
actions specified by this AD are intended to prevent the incapability
of the windshear computer to detect the true flap position, which, if
not corrected, could result in the inability of the flightcrew to avoid
a windshear encounter, and consequent reduced controllability of the
airplane.
DATES: Effective December 19, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of December 19, 1996.
ADDRESSES: The service information referenced in this AD may be
obtained from British Aerospace Regional Aircraft Limited, Avro
International Aerospace Division, Customer Support, Woodford Aerodrome,
Woodford, Cheshire SK7 1QR, England. 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: Tim Backman, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-2797; fax (206) 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 certain British Aerospace Model
BAe 146 and Model Avro 146-RJ series airplanes was published in the
Federal Register on August 26, 1996 (61 FR 43692). That action proposed
to require repetitive tests of the integrity of the electrical circuit
between the windshear computer and the flap position sensor, and repair
of the electrical wiring, if necessary. That action also proposed to
require replacement of existing windshear computers with new safe
flight windshear computers.
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.
Conclusion
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 as proposed.
Cost Impact
The FAA estimates that 41 British Aerospace Model BAe 146 series
airplanes and Model Avro 146-RJ series 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 cost impact of
the AD on U.S. operators is estimated to be $2,460, or $60 per
airplane, per test cycle.
The FAA estimates that it will take approximately 4 work hours per
airplane to accomplish the proposed replacement, at an average labor
rate of $60 per work hour. Required parts will be supplied by the
manufacturer at no cost to operators. Based on these figures, the cost
impact of the replacement on U.S. operators is estimated to be $9,840,
or $240 per airplane.
The cost impact figures discussed above are 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.
[[Page 58327]]
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:
96-23-08 British Aerospace: Amendment 39-9813. Docket 96-NM-40-AD.
Applicability: Model BAe 146 and Model Avro 146-RJ series
airplanes on which BAe Modification HCM40270A or HCM40270B (Safe
Flight Windshear Computer) has been installed, 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.
Compliance: Required as indicated, unless accomplished
previously.
To prevent the inability of the flightcrew to avoid a windshear
encounter and consequent reduced controllability of the airplane due
to the inability of the windshear computer to detect the true flap
position, accomplish the following:
(a) Within 300 landings or 60 days after the effective date of
this AD, whichever occurs first: Perform a test of the integrity of
the electrical circuit between the windshear computer and the flap
position sensor, in accordance with Avro International Aerospace
Alert Inspection Service Bulletin S.B. 34-A155, Revision 2, dated
August 9, 1995. Repeat the test thereafter at intervals not to
exceed 300 landings until the actions required by paragraph (c) of
this AD are accomplished.
(b) If any test required by paragraph (a) of this AD fails,
prior to further flight, repair the electrical wiring in accordance
with Avro International Aerospace Alert Inspection Service Bulletin
S.B. 34-A155, Revision 2, dated August 9, 1995. Thereafter, repeat
the test required by paragraph (a) of this AD at intervals not to
exceed 300 landings until the actions required by paragraph (c) of
this AD are accomplished.
(c) Within 6 months after the effective date of this AD: Replace
any Safe Flight windshear computer having part number 6508-2 or
6508-4 with a new Safe Flight windshear computer having part number
6508-5; and change the polarity of the polarizing keys; in
accordance with British Aerospace Modification Service Bulletin
SB.34-160-70548A, dated November 21, 1994. Accomplishment of these
actions constitutes terminating action for the repetitive tests
required by paragraph (a) of this AD.
(d) As of the effective date of this AD, no person shall install
a Safe Flight windshear computer having part number 6508-2 or 6508-4
on any airplane.
(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, 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.
(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 Avro
International Aerospace Alert Inspection Service Bulletin S.B. 34-
A155, Revision 2, dated August 9, 1995; or British Aerospace
Modification Service Bulletin SB.34-160-70548A, dated November 21,
1994; as applicable. Avro International Aerospace Alert Inspection
Service Bulletin S.B.34-A155, Revision 2, dated August 9, 1995,
contains the following list of specified effective pages:
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Revision
Page No. level shown Date shown on page
on page
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1, 2......................... 2 August 9, 1995.
3-5.......................... 1 September 10, 1993.
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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 Limited, Avro International Aerospace Division, Customer
Support, Woodford Aerodrome, Woodford, Cheshire SK7 1QR, England.
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.
(h) This amendment becomes effective on December 19, 1996.
Issued in Renton, Washington, on November 5, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-28871 Filed 11-13-96; 8:45 am]
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