[Federal Register Volume 69, Number 59 (Friday, March 26, 2004)]
[Proposed Rules]
[Pages 15740-15743]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-6685]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-316-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 supersedure of an existing 
airworthiness directive (AD), applicable to certain Saab Model SAAB 
2000 series airplanes, that currently requires repetitive inspections 
for discrepancies of the upper and lower areas of the backup struts in 
the left and right nacelles; and corrective actions, if necessary. This 
action would require repetitive inspections for cracks in the lower 
areas of the backup struts, and corrective action if necessary. This 
action would also require the eventual replacement of the backup struts 
with new, improved struts, which would terminate the repetitive 
inspections. The actions specified by the proposed AD are intended to 
prevent failure of the backup struts in the left and right nacelles due 
to fatigue cracking, which could result in loss of fail-safe redundancy 
in the design of the nacelle

[[Page 15741]]

in terms of load capability, and consequent separation of the engine 
from the airplane and subsequent reduced controllability of the 
airplane. This action is intended to address the identified unsafe 
condition.

DATES: Comments must be received by April 26, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-316-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. 2001-NM-316-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 98055-4056; 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 2001-NM-316-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. 2001-NM-316-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On June 28, 2000, the FAA issued AD 2000-13-09, amendment 39-11808 
(65 FR 41871, July 7, 2000), applicable to certain Saab Model SAAB 2000 
series airplanes, to require repetitive detailed visual and dye 
penetrant inspections of certain areas of the backup struts in the left 
and right nacelles to detect discrepancies; and corrective actions, if 
necessary. That action was prompted by issuance of mandatory continuing 
airworthiness information by a foreign civil airworthiness authority. 
The requirements of that AD are intended to prevent failure of the 
backup struts in the left and right nacelles due to fatigue cracking, 
which could result in loss of fail-safe redundancy in the design of the 
nacelle in terms of load capability, and consequent separation of the 
engine from the airplane and subsequent reduced controllability of the 
airplane.

Actions Since Issuance of Previous Rule

    The preamble to AD 2000-13-09 explains that we were considering 
further rulemaking for the requirements, which constituted ``interim 
action.'' We now have determined that further rulemaking is indeed 
necessary; this proposed AD follows from that determination. The 
manufacturer has improved the design and manufacturing of the backup 
struts, which will improve their fatigue strength.
    Further, although previous investigation indicated the possibility 
of cracking in the upper area of the backup strut, no cracks were found 
in that area. The manufacturer consequently determined that inspection 
of the upper strut area is unnecessary.

Explanation of Relevant Service Information

    The manufacturer has issued Saab Service Bulletins (SBs) 2000-54-
024 and 2000-54-025, both dated September 7, 2001. SB 2000-54-025 
describes procedures for repetitive fluorescent dye penetrant 
inspections for cracks of the lower areas of the backup struts of the 
left and right nacelles around the welding in the pipe and in the 
attachment fitting. Corrective actions include incorporating SB 2000-
54-024, which describes procedures for replacing--with new, improved 
parts--the backup struts in the electrical and hydraulic bays in the 
nacelles. SB 2000-54-025 provides operators the option of contacting 
Saab for repair instructions. Replacement of all four backup struts 
eliminates the need for the repetitive inspections. The Luftfartsverket 
(LFV), which is the airworthiness authority for Sweden, classified 
these SBs as mandatory and issued Swedish airworthiness directive 1-
165, dated September 10, 2001, 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 the FAA 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 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 supersede AD 2000-13-09 to 
require repetitive fluorescent dye penetrant

[[Page 15742]]

inspections for cracks of the lower ends of the nacelle backup struts. 
The proposed AD would also require immediate corrective action if 
necessary and eventual replacement of the backup struts with new, 
improved struts, which would terminate the repetitive inspections. The 
actions would be required to be accomplished in accordance with the SBs 
described previously, except as discussed below.

Differences Between the Proposed AD and the SBs/Swedish Airworthiness 
Directive

    SB 2000-54-025 and the Swedish airworthiness directive specify a 
compliance time for the inspection of 1,650 flight hours after the last 
inspection. We instead provide varying compliance times intended to 
ensure that all airplanes--regardless of inspection status or number of 
flight hours since the last inspection--would be inspected in a timely 
manner.
    Although SB 2000-54-025 specifies that operators may contact the 
manufacturer for disposition of certain repair (cracking) conditions, 
this proposed AD would not allow this option but would require 
operators to replace cracked struts in accordance with SB 2000-54-024.
    Although SB 2000-54-025 recommends that operators send Saab a 
report of the inspection results, this proposed AD would not require a 
report.

Additional Change to Existing AD

    We have reviewed the figures we have used over the past several 
years to calculate AD costs to operators. To account for various 
inflationary costs in the airline industry, we find it necessary to 
increase the labor rate used in these calculations from $60 per work 
hour to $65 per work hour. The cost impact information, below, reflects 
this increase in the specified hourly labor rate.

Cost Impact

    This proposed AD would affect about 3 airplanes of U.S. registry.
    The proposed inspection of the lower ends of the backup struts 
would take about 4 work hours per airplane, at an average labor rate of 
$65 per work hour. Based on these figures, the cost impact of this 
proposed action on U.S. operators is estimated to be $780, or $260 per 
airplane, per inspection cycle.
    Replacing all four backup struts would take about 80 work hours per 
airplane, at an average labor rate of $65 per work hour. Required parts 
would cost about $165,416 per airplane. Based on these figures, the 
cost impact of this proposed action on U.S. operators is estimated to 
be $511,848, or $170,616 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 removing amendment 39-11808 (65 FR 
41871, July 7, 2000), and by adding a new airworthiness directive (AD), 
to read as follows:

SAAB Aircraft AB: Docket 2001-NM-316-AD. Supersedes AD 2000-13-09, 
Amendment 39-11808.

    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 failure of the backup struts in the left and right 
nacelles due to fatigue cracking, which could result in loss of 
fail-safe redundancy in the design of the nacelle in terms of load 
capability, and consequent separation of the engine from the 
airplane and subsequent reduced controllability of the airplane, 
accomplish the following:

Inspection

    (a) At the applicable time specified in Table 1 of this AD: 
Perform a fluorescent dye penetrant inspection for cracks of the 
lower ends of the backup struts in the left and right nacelles, in 
accordance with SAAB Service Bulletin 2000-54-025, dated September 
7, 2001. Although the service bulletin specifies to submit certain 
information to the manufacturer, this AD does not require a report.

     Table 1.--Fluorescent Dye Penetrant Inspection Compliance Times
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                                      And if the
 If, as of the effective date of   airplane has, as       Then do the
   this new AD, the inspection     of the effective   inspection within--
   required by AD 2000-13-09,      date of this new
      amendment 39-11808--               AD--
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Has been done...................  Fewer than 4,500    1,650 flight hours
                                   flight cycles.      after
                                                       accomplishment of
                                                       the most recent
                                                       inspection done
                                                       per AD 2000-13-
                                                       09.
Has been done...................  4,500 or more       900 flight hours
                                   flight cycles.      after the most
                                                       recent inspection
                                                       done per AD 2000-
                                                       13-09.

[[Page 15743]]

 
Has not been done...............  Any number of       200 flight hours
                                   flight cycles.      after the
                                                       effective date of
                                                       this new AD.
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Follow-On/Corrective Actions

    (b) If no crack is found during the inspection required by 
paragraph (a) of this AD: Repeat the inspection at intervals not to 
exceed 1,650 flight hours, until the actions required by paragraph 
(d) of this AD have been done.
    (c) If any crack is found during any inspection required by 
paragraph (a) of this AD: Replace the cracked strut with a new, 
improved strut before further flight in accordance with SAAB Service 
Bulletin 2000-54-024, dated September 7, 2001. Although the service 
bulletin provides the option of contacting the manufacturer for 
repair instructions, this AD requires that any alternative repair be 
done in accordance with a method approved by either the Manager, 
International Branch, ANM-116, Transport Airplane Directorate, FAA; 
or the LFV (or its delegated agent). Replacement of a backup strut 
terminates the repetitive inspections required by this AD for that 
strut only.

Strut Replacement

    (d) Except as required by paragraph (c) of this AD: Within 36 
months after the effective date of this AD, replace all four backup 
struts in the electrical and hydraulic bays of the nacelles with 
new, improved struts, in accordance with the Accomplishment 
Instructions of SAAB Service Bulletin 2000-54-024, dated September 
7, 2001. Replacement of all four backup struts terminates the 
requirements of this AD.

Alternative Methods of Compliance

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

    Note 1: The subject of this AD is addressed in Swedish 
airworthiness directive 1-165, dated September 10, 2001.


    Issued in Renton, Washington, on March 19, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-6685 Filed 3-25-04; 8:45 am]
BILLING CODE 4910-13-P