[Federal Register Volume 69, Number 97 (Wednesday, May 19, 2004)]
[Proposed Rules]
[Pages 28860-28863]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-11291]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-347-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 various repetitive 
inspections for cracking of the drag and shear angles that attach the 
nacelle to the front spar of the wing, and related corrective action. 
The proposal also would require eventual modification of the drag and 
shear angles, which would end the repetitive inspections. This action 
is necessary to prevent fatigue cracking of the drag and shear angles, 
which could result in reduced structural integrity of the nacelle and 
wing. This action is intended to address the identified unsafe 
condition.

DATES: Comments must be received by June 18, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-347-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2002-NM-347-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 or 2000 or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Saab Aircraft AB, SAAB Aircraft Product Support, S-
581.88, Link[ouml]ping, Sweden. This information may be examined at the 
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Dan Rodina, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4057; telephone (425) 
227-2125; 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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2002-NM-347-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. 2002-NM-347-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 inspections 
done by a full-scale fatigue unit have revealed cracks in the drag 
angles that attach the nacelle to the wing box via the upper and lower 
wing skin; and in the shear angles that attach the nacelle to the front 
spar of the wing. Fatigue cracking of the drag and shear angles of the 
front spar of the wing could result in reduced structural integrity of 
the nacelle and wing.

Explanation of Relevant Service Information

    The manufacturer has issued Saab Service Bulletins 2000-54-026, 
Revision 01, and 2000-54-028, Revision 01, both dated June 20, 2002. 
The service bulletins describe procedures for

[[Page 28861]]

repetitive inspections for cracking and related corrective action. 
Service Bulletin 2000-54-026, Revision 01, describes procedures for 
detailed visual and eddy current inspections of the shear angles which 
attach the nacelle to the front spar of the wing; Service Bulletin 
2000-54-028, Revision 01, describes procedures for endoscope 
inspections of the drag angles which attach the nacelle to the wing box 
via the upper and lower wing skin. If any cracking is found, both 
service bulletins specify following Table 1 of the Accomplishment 
Instructions to determine the proper action (which includes repeating 
the inspections at certain intervals, depending on the length of the 
crack). Both service bulletins also recommend contacting the 
manufacturer if the cracking exceeds certain damage specifications in 
Table 1, and sending an inspection report to the manufacturer for 
further corrective action.
    Additionally, the manufacturer has issued Saab Service Bulletins 
2000-54-027, and 2000-54-029, both dated November 4, 2002, which 
describe procedures for modification of the upper and lower drag angles 
and the shear angles which attach the nacelle to the front spar of the 
wing. Accomplishment of both modifications eliminates the need for the 
repetitive inspections. The modification procedures in Service Bulletin 
2000-54-027 include an eddy current inspection of the surface of the 
shear angles and a rotating probe inspection of the hi-lok holes for 
cracking. If no cracking is found, the service bulletin describes 
procedures for installation of pressure pads on the shear angles. The 
modification procedures in Service Bulletin 2000-54-029 include an eddy 
current (rotating probe) inspection of the upper and lower drag angles 
for cracking. If no cracking is found, the service bulletin describes 
procedures for installation of pressure pads on the drag angles. If any 
cracking is found, both service bulletins describe procedures for 
determining the length and position of each crack, and sending a report 
to the manufacturer for further corrective action.
    Accomplishment of the actions specified in the service information 
is intended to adequately address the identified unsafe condition. The 
LFV classified this service information as mandatory and issued Swedish 
airworthiness directives 1-174 and 1-175, both dated April 30, 2002; 
and 1-180 and 1-181, both dated November 8, 2002; to ensure the 
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 us informed of the 
situation described above. We have 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 AD

    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 
the actions specified in the service information described previously, 
except as discussed below.

Differences Among Swedish Airworthiness Directives, Service 
Information, and Proposed AD

    Unlike the procedures described in the service bulletins, and 
referenced in the Swedish airworthiness directives, this proposed AD 
would not permit further flight if cracks are found in the drag and 
shear angles. We have determined that, because of the safety 
implications and consequences associated with such cracking, any 
cracked drag or shear angle must be repaired before further flight.
    The compliance time specified in the table in paragraph 1.D., 
`Compliance,' of Service Bulletin 2000-54-029 does not recommend a 
specific compliance time for the modification of the drag angles. The 
table cites cracking damage and different compliance times depending on 
the severity of the damage; however, we have determined the 
modification must be done before the accumulation of 24,000 flight 
cycles, as specified in the column citing no crack damage.
    Swedish airworthiness directives 1-174 and 1-175 require following 
the repetitive inspection intervals specified in Table 1 of the 
referenced service bulletins (determined by the severity of the 
cracking); however, this proposed AD follows the repetitive inspection 
interval in the column citing no crack damage as specified in Table 1 
of Service Bulletin 2000-54-028, Revision 01, for all airplanes.
    The compliance times specified above represent an appropriate 
interval of time for affected airplanes to continue to operate without 
compromising safety.
    The referenced service bulletins specify that operators may contact 
the manufacturer for disposition of certain repair (cracking) 
conditions; however, this proposed AD would not allow this option but 
would require operators to repair any cracking per a method approved by 
either the FAA or the LFV (or its delegated agent). In light of the 
type of repair that would be required to address the unsafe condition, 
and consistent with existing bilateral airworthiness agreements, we 
have determined that, for this proposed AD, a repair approved by either 
the FAA or the LFV would be acceptable for compliance with this 
proposed AD.
    The referenced service bulletins also specify that operators may 
contact the manufacturer to obtain repetitive inspection intervals if 
the cracking exceeds certain parameters; however, we have determined 
that operators must obtain appropriate repetitive inspection/repair 
procedures from either the FAA or the LFV (or its delegated agent).
    Although the service bulletins recommend that operators send the 
manufacturer a report of the inspection results, this proposed AD would 
not require submission of such a report.
    The above differences have been coordinated with the LFV.

Clarification of Inspection Type

    This proposed AD would specify a ``detailed'' inspection for 
cracking of the shear angles which attach the nacelle to the front spar 
of the wing, in lieu of a detailed ``visual'' inspection, as specified 
in Service Bulletin 2000-54-026, Revision 01. A note has been added to 
this proposed AD to define that inspection.

Cost Impact

    We estimate that 3 airplanes of U.S. registry would be affected by 
this proposed AD.
    It would take about 6 work hours per airplane to do the proposed 
inspections, at an average labor rate of $65 per work hour. Based on 
these figures, the cost impact of the proposed inspections on U.S. 
operators is estimated to be $1,170, or $390 per airplane, per 
inspection cycle.
    It would take about 40 work hours per airplane to do the proposed 
modification of the shear angles, at an average labor rate of $65 per 
work hour. Required parts would cost about $6,200 per airplane. Based 
on these figures, the cost impact of the proposed modification on U.S. 
operators is estimated to be $26,400, or $8,800 per airplane.

[[Page 28862]]

    It would take about 400 work hours per airplane to do the proposed 
modification of the drag angles, at an average labor rate of $65 per 
work hour. Required parts would cost about $41,794 per airplane. Based 
on these figures, the cost impact of the proposed modification on U.S. 
operators is estimated to be $203,382, or $67,794 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. The cost impact figures 
discussed in AD rulemaking actions represent only the time necessary to 
perform the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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 2002-NM-347-AD.

    Applicability: Model SAAB 2000 series airplanes, certificated in 
any category, serial numbers -004 through -063 inclusive.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent fatigue cracking of the drag and shear angles of the 
front spar of the wing, which could result in reduced structural 
integrity of the nacelle and wing, accomplish the following:

Repetitive Inspections

    (a) Do the inspections required by paragraphs (a)(1) and (a)(2) 
of this AD, at the applicable time specified in paragraph (b) of 
this AD.
    (1) Do a detailed inspection for cracking of the shear angles 
which attach the nacelle to the front spar of the wing, and an eddy 
current inspection for cracking around the fasteners, by doing all 
the actions per the Accomplishment Instructions of Saab Service 
Bulletin 2000-54-026, Revision 01, dated June 20, 2002.
    (2) Do an endoscope inspection of the upper and lower drag 
angles for cracking, and an eddy current inspection for cracking 
around the fasteners, by doing all the actions per the 
Accomplishment Instructions of Saab Service Bulletin 2000-54-028, 
Revision 01, dated June 20, 2002.

    Note 1: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

Compliance Times

    (b) Do the inspections required by paragraph (a) of this AD at 
the applicable compliance time specified in paragraph (b)(1), 
(b)(2), or (b)(3) of this AD. Repeat the inspections thereafter at 
intervals not to exceed 4,000 flight cycles until the modification 
required by paragraph (e) of this AD is done.
    (1) For airplanes that have accumulated 14,000 or more total 
flight cycles as of the effective date of this AD: Inspect within 
500 flight cycles after the effective date of this AD.
    (2) For airplanes that have accumulated 10,000 or more total 
flight cycles, but fewer than 14,000 total flight cycles as of the 
effective date of this AD: Inspect within 1,000 flight cycles after 
the effective date of this AD.
    (3) For airplanes that have accumulated fewer than 10,000 total 
flight cycles as of the effective date of this AD: Inspect within 
2,000 flight cycles after the effective date of this AD.

Corrective Action

    (c) If any cracking is found during any inspection required by 
this AD: Before further flight, repair the cracking per a method 
approved by either the Manager, International Branch, ANM-116, 
Transport Airplane Directorate, FAA, or the LFV (or its delegated 
agent). In lieu of repairing the cracking, the modifications 
required by paragraph (e) of this AD may be done before further 
flight, which would end the repetitive inspections required by 
paragraphs (a) and (b) of this AD.

Inspections Done Per Previous Issues of Service Bulletins

    (d) Inspections done before the effective date of this AD per 
Saab Service Bulletins 2000-54-026 and 2000-54-028, both dated April 
26, 2002, are considered acceptable for compliance with the 
corresponding actions specified in this AD.

Terminating Action

    (e) Except as provided by paragraph (c) of this AD: Do the 
modifications of the drag and shear angles of the front spar of the 
wing at the times specified in paragraphs (e)(1) and (e)(2) of this 
AD. Accomplishment of these modifications ends the repetitive 
inspections required by paragraphs (a) and (b) of this AD.
    (1) Before the accumulation of 20,000 total flight cycles: 
Modify the shear angles that attach the nacelle to the front spar of 
the wing by doing all the actions per the Accomplishment 
Instructions of Saab Service Bulletin 2000-54-027, dated November 4, 
2002.
    (2) Before the accumulation of 24,000 total flight cycles: 
Modify the upper and lower drag angles by doing all the actions per 
the Accomplishment Instructions of Saab Service Bulletin 2000-54-
029, dated November 4, 2002.

No Reporting Requirement

    (f) Although the Saab Service Bulletins referenced in this AD 
recommend submitting certain information to the manufacturer, this 
AD does not include such a requirement.

Alternative Methods of Compliance

    (g) In accordance with 14 CFR 39.19, the Manager, International 
Branch, ANM-116, Transport Airplane Directorate, is authorized to 
approve alternative methods of compliance for this AD.

    Note 2: The subject of this AD is addressed in Swedish 
airworthiness directives 1-174 and 1-175, both dated April 30, 2002; 
and Swedish airworthiness directives 1-180 and 1-181, both dated 
November 8, 2002.



[[Page 28863]]


    Issued in Renton, Washington, on May 12, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-11291 Filed 5-18-04; 8:45 am]
BILLING CODE 4910-13-P