[Federal Register Volume 63, Number 110 (Tuesday, June 9, 1998)]
[Proposed Rules]
[Pages 31380-31382]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-15248]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-151-AD]
RIN 2120-AA64
Airworthiness Directives; Saab Model SAAB 2000 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Saab Model SAAB 2000
series airplanes. This proposal would require a one-time inspection for
cracking of the rear pressure bulkhead; and installation of a
reinforcement angle on the rear pressure bulkhead; or repair, if
necessary. This proposal is prompted by issuance of mandatory
continuing airworthiness information by a foreign civil airworthiness
authority. The actions specified by the proposed AD are intended to
prevent cracking of the rear pressure bulkhead, which could result in
sudden loss of cabin pressure and the inability to withstand fail-safe
loads.
DATES: Comments must be received by July 9, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-151-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except
Federal holidays.
The service information referenced in the proposed rule may be
obtained from Saab Aircraft AB, SAAB Aircraft Product Support, S-
581.88, Linkoping, Sweden. This information may be examined at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington.
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:
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 shall 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 summarizing each FAA-public contact concerned with
the substance of this 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 Number 98-NM-151-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules
Docket No. 98-NM-151-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Luftfartsverket (LFV), which is the airworthiness authority for
Sweden, notified the FAA that an unsafe condition may exist on certain
Saab Model SAAB 2000 series airplanes. The LFV advises that, during
full-scale fatigue testing on a test article, a crack was detected on
the radius of the lower forward flange that connects the rear pressure
bulkhead to the fuselage skin. The crack occurred when the test article
reached 68,000 simulated flights. The LFV further advises that
reinforcement of the lower forward flange area that connects the rear
pressure bulkhead to the fuselage skin is required to meet the design
life of the airplane. Such cracking, if not corrected, could result in
sudden loss of cabin pressure and the inability to withstand fail-safe
loads.
Explanation of Relevant Service Information
The manufacturer has issued SAAB Service Bulletin 2000-53-026,
dated February 27, 1998, which describes procedures for a one-time
inspection to detect cracking of the rear pressure bulkhead in the area
of the lower forward flange that connects to the fuselage skin.
Additionally, for airplanes on which no cracking is found, the service
bulletin describes procedures for installation of a reinforcement angle
on the rear pressure bulkhead in the area of the lower forward flange
that connects to the fuselage skin. Accomplishment of the actions
specified in the service bulletin is intended to adequately address the
identified unsafe condition. The LFV classified this service bulletin
as mandatory and issued Swedish airworthiness directive 1-122, dated
March 2, 1998, in order to assure the
[[Page 31381]]
continued airworthiness of these airplanes in Sweden.
FAA's Conclusions
This airplane model is manufactured in Sweden 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 LFV has kept the FAA informed of
the situation described above. The FAA has examined the findings of the
LFV, 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 Proposed 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, the proposed AD would require accomplishment of
actions specified in the service bulletin described previously, except
as discussed below.
Differences Between Proposed Rule and Service Bulletin
Operators should note that although the service bulletin specifies
that the manufacturer may be contacted for disposition of cracks, this
proposal would require the repair of those cracks be accomplished in
accordance with a method approved by either the Manager, International
Branch, ANM-116, FAA Transport Directorate; or the LFV (or its
delegated agent). In light of the type of repair that would be required
to address the identified unsafe condition, and in consonance with
existing bilateral airworthiness agreements, the FAA has determined
that, for this proposed AD, a repair approved by either the FAA or the
LFV (or its delegated agent) would be acceptable for compliance with
this proposed AD.
Cost Impact
The FAA estimates that 3 airplanes of U.S. registry would be
affected by this proposed AD.
It would take approximately 6 work hours per airplane to accomplish
the proposed inspection, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of the inspection proposed by
this AD on U.S. operators is estimated to be $1,080, or $360 per
airplane.
The proposed installation would take approximately 10 work hours
per airplane, at an average labor rate of $60 per work hour. Based on
these figures, the cost impact of the installation proposed by this AD
on U.S. operators is estimated to be $1,800, or $600 per airplane.
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the proposed 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 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 proposed
regulation (1) is not a `significant regulatory action' under Executive
Order 12866; (2) is not a `significant rule' under the 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 is contained in the Rules Docket. A
copy of it may be obtained by contacting the Rules Docket at the
location provided under the caption ADDRESSES.
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 the following new
airworthiness directive:
SAAB Aircraft AB: Docket 98-NM-151-AD.
Applicability: Model SAAB 2000 series airplanes, manufacturer
serial numbers 004 through 050 inclusive, 052, 053, and 054;
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 (b) 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 cracking on the rear pressure bulkhead, which could
result in sudden loss of cabin pressure and the inability to
withstand fail-safe loads, accomplish the following:
(a) Within 4,000 flight cycles after the effective date of this
AD, perform a one-time visual inspection for cracking on the rear
pressure bulkhead in the area of the lower forward flange that
connects to the fuselage skin, in accordance with SAAB Service
Bulletin 2000-53-026, dated February 27, 1998.
(1) If no crack is detected, prior to further flight, install a
reinforcement angle on the rear pressure bulkhead in the area of the
lower forward flange that connects to the fuselage skin, in
accordance with the service bulletin. After accomplishment of the
installation, no further action is required by this AD.
(2) If any crack is detected, prior to further flight, repair in
accordance with a method approved by either the Manager,
International Branch, ANM-116, FAA, Transport Airplane Directorate,
or the Luftfartsverket (or its delegated agent).
(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, International Branch, ANM-116.
Operators shall submit their request 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.
(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.
Note 3: The subject of this AD is addressed in Swedish
airworthiness directive 1-122, dated March 2, 1998.
[[Page 31382]]
Issued in Renton, Washington, on June 3, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-15248 Filed 6-8-98; 8:45 am]
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