[Federal Register Volume 64, Number 178 (Wednesday, September 15, 1999)]
[Rules and Regulations]
[Pages 49964-49966]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-23352]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-220-AD; Amendment 39-11310; AD 99-19-21]
RIN 2120-AA64


Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Saab Model SAAB SF340A and SAAB 340B series 
airplanes, that requires repetitive inspections to detect cracking 
around certain fastener holes and adjacent areas of the front spar of 
the horizontal stabilizers; and corrective actions, if necessary. This 
amendment also requires repetitive x-ray inspections, cold working of 
certain fastener holes of the front spar of the horizontal stabilizers, 
and follow-on actions; and installation of new fasteners, which 
constitutes terminating action for the repetitive inspections required 
by this AD. This amendment is prompted by the issuance of mandatory 
continuing airworthiness information by a foreign civil airworthiness 
authority. The actions specified by this AD are intended to prevent 
failure of the front spar due to fatigue cracking around certain 
fastener holes of the front spar of the horizontal stabilizers, which 
could result in reduced structural integrity of the airplane.

DATES: Effective October 20, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 20, 1999.
ADDRESSES: The service information referenced in this AD may be 
obtained from Saab Aircraft AB, SAAB Aircraft Product Support, S-
581.88, Linkoping, Sweden. 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: 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: 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 Saab Model SAAB SF340A and 
SAAB 340B series airplanes was published as a supplemental notice of 
proposed rulemaking (NPRM) in the Federal Register on July 15, 1999 (64 
FR 38150). That action proposed to require repetitive inspections to 
detect cracking around certain fastener holes and adjacent areas of the 
front spar of the horizontal stabilizers; and corrective actions, if 
necessary. That action also proposed to require cold working of certain 
fastener holes of the front spar of the horizontal stabilizers, and 
follow-on actions; and installation of new fasteners, which would 
constitute terminating action for the repetitive inspections. That 
action also proposed to add repetitive x-ray inspections.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were submitted in response 
to the proposal or the FAA's determination of the cost to the public.

Explanation of Change Made to Final Rule

    The FAA has added a note to the final rule to clarify the 
definition of a detailed visual inspection.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the change described 
previously. The FAA has determined that this change will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    The FAA estimates that 279 airplanes of U.S. registry will be 
affected by this AD.

[[Page 49965]]

    It will take approximately 4 work hours per airplane to perform the 
required detailed visual inspection, at an average labor rate of $60 
per work hour. Based on these figures, the cost impact of the 
inspection required by this AD on U.S. operators is estimated to be 
$66,960, or $240 per airplane, per inspection cycle.
    It will take approximately 6 work hours per airplane to accomplish 
the required eddy current and x-ray inspections, at an average labor 
rate of $60 per work hour. Based on these figures, the cost impact of 
the inspections required by this AD on U.S. operators is estimated to 
be $100,440, or $360 per airplane, per inspection cycle.
    It will take approximately 42 work hours to accomplish the cold 
working of the fastener holes, at an average labor rate of $60 per work 
hour. Required parts will cost approximately $400 per airplane. Based 
on these figures, the cost impact of the cold work required by this AD 
on U.S. operators is estimated to be $814,680, or $2,920 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.

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:
  99-19-21 SAAB Aircraft AB: Amendment 39-11310. Docket 98-NM-220-
AD.

    Applicability: Model SAAB SF340A series airplanes, 
manufacturer's serial numbers -004 through -159 inclusive; and SAAB 
340B series airplanes, manufacturer's serial numbers -160 through -
439 inclusive; 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, unless accomplished 
previously.
    To prevent failure of the front spar due to fatigue cracking 
around certain fastener holes of the front spar of the horizontal 
stabilizers, which could result in reduced structural integrity of 
the airplane, accomplish the following:

    Note 2: For the purposes of this AD, a detailed visual 
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.''

Initial and Repetitive Inspections

    (a) For Model SAAB SF340A series airplanes with manufacturer's 
serial numbers -004 through -159 inclusive: Perform the inspections 
(detailed visual, eddy current, and x-ray) specified in paragraph 
2.D. of the Accomplishment Instructions of Saab Service Bulletin 
340-55-033, Revision 04, dated December 1, 1998, to detect cracking 
around certain fastener holes and adjacent areas of the front spar 
of the horizontal stabilizer, in accordance with the service 
bulletin, at the time specified in paragraph (a)(1), (a)(2), or 
(a)(3) of this AD, as applicable. Thereafter, repeat only the eddy 
current and x-ray inspections at intervals not to exceed 12,000 
flight cycles until the requirements of paragraph (d) of this AD are 
accomplished.
    (1) For airplanes that have accumulated less than 22,000 total 
flight cycles as of the effective date of this AD: Perform an eddy 
current and an x-ray inspection prior to the accumulation of 22,000 
total flight cycles, or within 2,000 flight cycles after the 
effective date of this AD, whichever occurs later.
    (2) For airplanes that have accumulated 22,000 or more total 
flight cycles and less than 30,000 total flight cycles as of the 
effective date of this AD: Accomplish the requirements of paragraphs 
(a)(2)(i) and (a)(2)(ii) of this AD.
    (i) Perform a detailed visual inspection within 800 flight 
cycles after the effective date of this AD; and
    (ii) Perform an eddy current and an x-ray inspection within 
2,000 flight cycles after the effective date of this AD.
    (3) For airplanes that have accumulated 30,000 or more total 
flight cycles as of the effective date of this AD: Accomplish the 
requirements of paragraphs (a)(3)(i) and (a)(3)(ii) of this AD.
    (i) Perform a detailed visual inspection within 400 flight 
cycles after the effective date of this AD; and
    (ii) Perform an eddy current and an x-ray inspection within 
1,200 flight cycles after the effective date of this AD.

Initial and Repetitive Inspections

    (b) For Model SAAB 340B series airplanes with manufacturer's 
serial numbers -160 through -439 inclusive: Perform the inspections 
(detailed visual, eddy current, and x-ray) specified in paragraph 
2.D. of the Accomplishment Instructions of Saab Service Bulletin 
340-55-033, Revision 04, dated December 1, 1998, to detect cracking 
around certain fastener holes and adjacent areas of the front spar 
of the horizontal stabilizer, in accordance with the service 
bulletin, at the time specified in paragraph (b)(1), (b)(2), or 
(b)(3) of this AD, as applicable. Thereafter, repeat only the eddy 
current and x-ray inspections at intervals not to exceed 6,000 
flight cycles until the requirements of paragraph (d) of this AD are 
accomplished.
    (1) For airplanes that have accumulated less than 12,000 total 
flight cycles as of the effective date of this AD: Perform an eddy 
current and an x-ray inspection prior to the accumulation of 12,000 
total flight cycles, or within 2,000 flight cycles after the 
effective date of this AD, whichever occurs later.
    (2) For airplanes that have accumulated 12,000 or more total 
flight cycles and less than 16,000 total flight cycles as of the 
effective date of this AD: Accomplish the requirements of paragraphs 
(b)(2)(i) and (b)(2)(ii) of this AD.

[[Page 49966]]

    (i) Perform a detailed visual inspection within 800 flight 
cycles after the effective date of this AD; and
    (ii) Perform an eddy current and an x-ray inspection within 
2,000 flight cycles after the effective date of this AD.
    (3) For airplanes that have accumulated 16,000 or more total 
flight cycles as of the effective date of this AD: Accomplish the 
requirements of paragraphs (b)(3)(i) and (b)(3)(ii) of this AD.
    (i) Perform a detailed visual inspection within 400 flight 
cycles after the effective date of this AD; and
    (i) Perform a detailed visual inspection within 400 flight 
cycles after the effective date of this AD; and (ii) Perform an eddy 
current and an x-ray inspection within 1,200 flight cycles after the 
effective date of this AD.

Corrective Actions

    (c) If any cracking is detected during any inspection required 
by paragraph (a) or (b) of this AD, prior to further flight, either 
repair in accordance with a method approved by the Manager, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
or the Luftfartsverket (LFV) (or its delegated agent); or accomplish 
the requirements of paragraph (d) of this AD.

    Note 3: Inspections to detect cracking around certain fastener 
holes and adjacent areas of the front spar of the horizontal 
stabilizers that have been accomplished prior to the effective date 
of this AD in accordance with Saab Service Bulletin 340-55-033, 
Revision 03, dated January 22, 1998, are considered acceptable for 
compliance with the applicable action specified by this AD.

Terminating Action

    (d) For all airplanes: Except as provided by paragraph (e) of 
this AD, accomplish cold working of certain fastener holes of the 
front spar of the horizontal stabilizers, and follow-on actions; and 
install new fasteners; in accordance with Saab Service Bulletin 340-
55-034, dated October 16, 1998; at the time specified in paragraph 
(d)(1), (d)(2), or (d)(3) of this AD, as applicable. Accomplishment 
of this action constitutes terminating action for this AD.
    (1) For all airplanes that have accumulated less than 26,000 
total flight cycles as of the effective date of this AD: Within 
10,000 flight cycles after the effective date of this AD.
    (2) For all airplanes that have accumulated 26,000 or more total 
flight cycles and less than 30,000 total flight cycles as of the 
effective date of this AD: Within 6,000 flight cycles after the 
effective date of this AD.
    (3) For all airplanes that have accumulated 30,000 or more total 
flight cycles as of the effective date of this AD: Within 3,000 
flight cycles after the effective date of this AD.
    (e) If any crack is detected during the accomplishment of 
paragraph (d) of this AD, and if the service bulletin listed in 
paragraph (d) of this AD specifies to contact the manufacturer for 
an appropriate corrective action: Prior to further flight, repair in 
accordance with a method approved by the Manager, International 
Branch, ANM-116, or the LFV (or its delegated agent).

Alternative Method of Compliance

    (f) 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 requests through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, International Branch, ANM-116.
    Note 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

Special Flight Permits

    (g) 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.

Incorporation by Reference

    (h) Except as provided by paragraphs (c) and (e) of this AD, the 
actions shall be done in accordance with Saab Service Bulletin 340-
55-033, Revision 04, dated December 1, 1998; and Saab Service 
Bulletin 340-55-034, dated October 16, 1998; as applicable. 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 Saab Aircraft AB, SAAB Aircraft 
Product Support, S-581.88, Linkoping, Sweden. 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.

    Note 5: The subject of this AD is addressed in Swedish 
airworthiness directives 1-110R2, dated December 7, 1998, and 1-133, 
dated October 20, 1998.

    (i) This amendment becomes effective on October 20, 1999.

    Issued in Renton, Washington, on September 1, 1999.
Dorenda D. Baker,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-23352 Filed 9-14-99; 8:45 am]
BILLING CODE 4910-13-P