[Federal Register Volume 63, Number 103 (Friday, May 29, 1998)]
[Proposed Rules]
[Pages 29362-29364]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-14189]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-CE-03-AD]
RIN 2120-AA64
Airworthiness Directives; British Aerospace Model B.121 Series 1,
2, and 3 Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Supplemental notice of proposed rulemaking (NPRM); Reopening of
the comment period.
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SUMMARY: This document proposes to revise an earlier proposed
airworthiness directive (AD) that would have required the following on
certain British Aerospace Model B.121 Series 1, 2, and 3 airplanes:
installing an inspection opening in the area of the main spar web,
repetitively inspecting the area at the main spar web for cracks and
the area of the wing to fuselage attach bolt holes for corrosion, and
repairing or replacing any cracked or corroded part. The proposed AD
was the result of mandatory continuing airworthiness information (MCAI)
issued by the airworthiness authority for the United Kingdom. Since
issuing the NPRM, British Aerospace has developed additional service
information to that referenced in the previous proposal to include the
installation of nuts of improved design at the wing to fuselage main-
spar attachment fittings and the deletion of the inspection of the area
of the wing to fuselage attach bolt holes for corrosion. The improved
design nuts provide better torque retention than the nuts originally
installed. The Federal Aviation Administration (FAA) has determined
that the above-referenced changes in the revised service information
should be incorporated into the NPRM, and that the comment period for
the proposal should be reopened and the public should have additional
time to comment. The actions specified by the proposed AD are intended
to prevent structural failure of the main spar web area caused by
fatigue cracking or separation of the wing caused by loose nuts at the
wing to fuselage main-spar attachment fittings, which could result in
loss of control of the airplane.
DATES: Comments must be received on or before July 3, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Central Region, Office of the Regional Counsel,
Attention: Rules Docket No. 98-CE-03-AD, Room 1558, 601 E. 12th Street,
Kansas City, Missouri 64106. Comments may be inspected at this location
between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted.
Service information that applies to the proposed AD may be obtained
from British Aerospace (Operations) Limited, British Aerospace Regional
Aircraft, Prestwick International Airport, Ayrshire, KA9 2RW, Scotland;
telephone: (01292) 479888; facsimile: (01292) 479703. This information
also may be examined at the Rules Docket at the address above.
FOR FURTHER INFORMATION CONTACT: Mr. Roger Chudy, Aerospace Engineer,
Small Airplane Directorate, Aircraft Certification Service, 1201
Walnut, suite 900, Kansas City, Missouri 64106; telephone: (816) 426-
6932; facsimile: (816) 426-2169
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications should identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed 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
[[Page 29363]]
proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket No. 98-CE-03-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of Supplemental NPRM's
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Central Region, Office of the Regional Counsel, Attention:
Rules Docket No. 98-CE-03-AD, Room 1558, 601 E. 12th Street, Kansas
City, Missouri 64106.
Discussion
A proposal to amend part 39 of the Federal Aviation Regulations (14
CFR part 39) to include an AD that would apply to certain British
Aerospace Model B.121 Series 1, 2, and 3 airplanes was published in the
Federal Register as a notice of proposed rulemaking (NPRM) on March 16,
1998 (63 FR 12708). The NPRM proposed to require installing an
inspection opening in the area of the main spar web, repetitively
inspecting the area at the main spar web for cracks and the area of the
wing to fuselage attach bolt holes for corrosion, and repairing or
replacing any cracked or corroded part. Accomplishment of the proposed
inspections would be required in accordance with British Aerospace PUP
Mandatory Service Bulletin No. B121/102, Revision No. 1, Issued April
16, 1997. If necessary, the proposed repair or replacement would be
required in accordance with a scheme obtained from the manufacturer
through the FAA, Small Airplane Directorate.
The NPRM was the result of mandatory continuing airworthiness
information (MCAI) issued by the airworthiness authority for the United
Kingdom.
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.
Events Since Issuance of the NPRM
Since issuance of the NPRM, British Aerospace has developed
additional service information to that referenced in the previous
proposal to include the installation of nuts of improved design at the
wing to fuselage main-spar attachment fittings and the deletion of the
inspection at the area of the wing to fuselage attach bolt holes for
corrosion. The improved design nuts provide better torque retention
than the ones originally installed.
In addition, British Aerospace has re-examined the service history
and evaluated reports from the field and has changed the compliance
time (that is referenced in the service information) for the inspection
opening installation and the initial eddy current inspection to upon
the accumulation of 2,000 flying hours.
To incorporate the above changes, British Aerospace has issued the
following service bulletins, which supersede British Aerospace PUP
Mandatory Service Bulletin No. B121/102, Revision No. 1, Issued April
16, 1997:
--British Aerospace PUP Mandatory Service Bulletin No. B121/106, dated
January 12, 1998, which specifies procedures for replacing the nuts
(with improved design nuts) at the wing to fuselage main-spar
attachment fittings; and
--British Aerospace PUP Mandatory Service Bulletin No. B121/105, dated
January 12, 1998, which specifies procedures for installing an
inspection opening in the area of the main spar web, and inspecting the
area at the main spar web for cracks. These procedures are basically
the same as contained in British Aerospace PUP Mandatory Service
Bulletin No. B121/102, Revision No. 1, Issued April 16, 1997.
The FAA's Determination
After examining all information related to the subject described in
this document, the FAA has determined that:
--Improved design nuts should be installed at the wing to fuselage
main-spar attachment fittings;
--The improved service information should be incorporated into the
proposed AD;
--The compliance time of the proposed inspection opening installation
and initial eddy current inspection should be changed to coincide with
the service information referenced above; and
--AD action should be taken to incorporate these changes to prevent
structural failure of the main spar web area caused by fatigue cracking
or separation of the wing caused by loose nuts at the wing to fuselage
main-spar attachment fittings, which could result in loss of control of
the airplane.
The Supplemental NPRM
Since installing improved design nuts at the wing to fuselage main-
spar attachment fittings proposes actions that go beyond the scope of
what was already proposed, the FAA is reopening the comment period to
allow the public additional time to comment on this proposed action.
Cost Impact
The FAA estimates that 2 airplanes in the U.S. registry would be
affected by the proposed AD; that it would take approximately 37
workhours per airplane to accomplish the proposed initial inspection,
inspection opening installation, and improved design nut installations;
that the average labor rate is approximately $60 an hour. There is no
cost for the parts to accomplish the proposed replacements. Based on
these figures, the total cost impact of the proposed AD on U.S.
operators is estimated to be $4,440, or $2,220 per airplane. These
figures only take into account the cost of the proposed initial
inspections, inspection opening installation, and improved design nut
installations; and do not take into account the cost of repetitive
inspections. The FAA has no way of determining the number of repetitive
inspections each owner/operator of the affected airplanes will incur.
Regulatory Impact
The regulations proposed herein would 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
proposal would 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) if promulgated,
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 draft regulatory evaluation
prepared for this action has been placed in the Rules Docket. A copy of
it may be obtained by contacting the Rules Docket at the location
provided under the caption ADDRESSES.
[[Page 29364]]
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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:
British Aerospace (Operations) Limited: Docket No. 98-CE-03-AD.
Applicability: Model B.121 Series 1, 2, and 3 airplanes, all
serial numbers, 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 (f) 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 in the body of this AD, unless
already accomplished.
To prevent structural failure of the main spar web area caused
by fatigue cracking or separation of the wing caused by loose nuts
at the wing to fuselage main-spar attachment fittings, which could
result in loss of control of the airplane, accomplish the following:
(a) Within the next 100 hours time-in-service (TIS) after the
effective date of this AD, replace the nuts (with improved design
nuts) at the wing to fuselage main-spar attachment fittings in
accordance with British Aerospace PUP Mandatory Service Bulletin No.
B121/106, dated January 12, 1998.
(b) Upon accumulating 2,000 hours TIS on the main spar or within
the next 50 hours TIS, whichever occurs later, install an inspection
opening and inspect, using eddy current methods, the area at the
main spar web for cracks in accordance with the ACCOMPLISHMENT
INSTRUCTIONS section of British Aerospace PUP Mandatory Service
Bulletin No. B121/105, dated January 12, 1998.
Note 2: Accomplishing the installation inspection opening and
initial eddy current inspection required by this AD in accordance
with British Aerospace PUP Mandatory Service Bulletin No. B121/102,
Revision No. 1, Issued April 16, 1997, is considered ``already
accomplished'' for the requirements of paragraph (b) of this AD.
(c) Within 800 hours TIS after the initial inspection required
by paragraph (b) of this AD, and thereafter at intervals not to
exceed 800 hours TIS, reinspect the area of the main spar web as
specified in paragraph (b) of this AD.
(d) If any cracks are found during any inspection required by
this AD, prior to further flight, accomplish the following:
(1) Obtain a repair or replacement scheme from the manufacturer
through the FAA, Small Airplane Directorate, at the address
specified in paragraph (e) of this AD; and
(2) Incorporate this scheme and continue to repetitively inspect
as required by paragraph (c) of this AD, unless specified
differently in the instructions to the repair or replacement scheme.
(e) 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.
(f) 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, Aircraft Certification Service, 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.
(g) Questions or technical information related to the service
information referenced in this document should be directed to
British Aerospace (Operations) Limited, British Aerospace Regional
Aircraft, Prestwick International Airport, Ayrshire, KA9 2RW,
Scotland; telephone: (01292) 479888; facsimile: (01292) 479703. 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.
Note 4: The subject of this AD is addressed in British AD 005-
01-98, not dated.
Issued in Kansas City, Missouri, on May 21, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-14189 Filed 5-28-98; 8:45 am]
BILLING CODE 4910-13-P
