[Federal Register Volume 61, Number 245 (Thursday, December 19, 1996)]
[Rules and Regulations]
[Pages 66885-66887]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-31111]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-201-AD; Amendment 39-9848; AD 96-25-06]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.


[[Page 66886]]


ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Saab Model SAAB SF340A and SAAB 340B series 
airplanes, that requires inspections to detect damage or cracking of 
the forward and aft attachment lugs of the flap fittings at wing 
station (WS) 123.38; an inspection to verify that the sizes of the 
holes of the flap fittings are within specified limits and to ensure 
that the swaged bushings are not loose; and modification of the flap 
fittings. This amendment is prompted by a report of jamming of a flap 
due to incorrect tolerances of the flap-hinge installation, which 
caused high bearing stress on the bushings in the flap fittings. The 
actions specified by this AD are intended to prevent such high bearing 
stress, which could result in wear on the bushings, cracking of the 
flap fittings, and breakage of the lugs; these conditions could result 
in jamming of the flaps and consequent reduced controllability of the 
airplane.

DATES: Effective January 27, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 27, 1997.

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: Ruth Harder, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-1721; fax (206) 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 in the Federal Register on 
September 11, 1996 (61 FR 47831). That action proposed to require 
repetitive visual inspections to detect damage or cracking of the 
forward and aft attachment lugs of the flap fittings at wing station 
(WS) 123.38; an eventual inspection to verify that the sizes of the 
inboard and outboard holes (swaged bushings) of the flap fittings are 
within specified limits and to ensure that the swaged bushings are not 
loose; and modification of the flap fittings.
    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.

Conclusion

    The FAA has determined that air safety and the public interest 
require the adoption of the rule as proposed.

Cost Impact

    The FAA estimates that 224 Saab Model SAAB SF340A and SAAB 340B 
series airplanes of U.S. registry will be affected by this AD, that it 
will take approximately 1 work hour per airplane to accomplish the 
required visual inspection, and that the average labor rate is $60 per 
work hour. Based on these figures, the cost impact of the required 
visual inspection on U.S. operators is estimated to be $13,440, or $60 
per airplane.
    For operators required to accomplish Modification 2628--Part 1, the 
FAA estimates that it will take approximately 30 work hours per 
airplane to accomplish it, at an average labor rate of $60 per work 
hour. Required parts will cost $100 per airplane. Based on these 
figures, the cost impact of Modification 2628--Part 1 on U.S. operators 
is estimated to be $1,900 per airplane.
    For operators required to accomplish Modification 2628--Part 2, the 
FAA estimates that it will take approximately 60 work hours per 
airplane to accomplish it, at an average labor rate of $60 per work 
hour. Required parts will cost $100 per airplane. Based on these 
figures, the cost impact of Modification 2628--Part 2 on U.S. operators 
is estimated to be $3,700 per airplane.
    For operators required to accomplish Modification 2628--Part 3, the 
FAA estimates that it will take approximately 96 work hours per 
airplane to accomplish it, at an average labor rate of $60 per work 
hour. Required parts will cost $1,400 per airplane. Based on these 
figures, the cost impact of Modification 2628--Part 3 on U.S. operators 
is estimated to be $7,160 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:

96-25-06--SAAB Aircraft AB: Amendment 39-9848. Docket 95-NM-201-AD.

    Applicability: Model SAAB SF340A series airplanes, serial 
numbers 004 through 159 inclusive; and Model SAAB 340B series 
airplanes, serial numbers 160 through 379 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 
otherwise 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

[[Page 66887]]

owner/operator must request approval for an alternative method of 
compliance in accordance with paragraph (c) 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 high bearing stress on the bushings in the flap 
fittings, which could result in jamming of the flaps and consequent 
reduced controllability of the airplane, accomplish the following:
    (a) Within 800 hours time-in-service after the effective date of 
this AD: Perform a visual inspection to detect damage or cracking of 
the forward and aft attachment lugs of the flap fittings at wing 
station (WS) 123.38, in accordance with Saab Service Bulletin SAAB 
340-57-027, Revision 01, dated June 30, 1995.
    (1) If no cracking or damage is found, and the flap fittings 
have not been modified or replaced, repeat the visual inspection 
thereafter at intervals not to exceed 800 hours time-in-service.
    (2) If any cracking is found, prior to further flight, replace 
the flap fittings with new improved flap fittings, and install 
improved bushings, in accordance with the Accomplishment 
Instructions (Modification 2628--Part 3) of the service bulletin. 
After this modification is accomplished, no further action is 
required by this paragraph.
    (b) Within 4,500 hours time-in-service after the effective date 
of this AD, perform an inspection to determine the size of the 
inboard and outboard holes (swaged bushings) of the flap fittings, 
and to detect loose swaged bushings, in accordance with Saab Service 
Bulletin SAAB 340-57-027, Revision 01, dated June 30, 1995.
    (1) If the sizes of the holes are within the limits specified in 
the service bulletin, and if no loose swaged bushings are found, 
prior to further flight, install improved bushings in accordance 
with the Accomplishment Instructions (Modification 2628--Part 1) of 
the service bulletin. After this modification is accomplished, no 
further action is required by this AD.
    (2) If the size of any hole is outside the limits specified in 
the service bulletin, or if any loose swaged bushing is found, prior 
to further flight, install oversize bushings in the flap fittings, 
and install improved bushings, in accordance with the Accomplishment 
Instructions (Modification 2628--Part 2) of the service bulletin. 
After this modification is accomplished, no further action is 
required by this AD.
    (c) 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, Manager, Standardization Branch, 
ANM-113, FAA, Transport Airplane Directorate. Operators shall submit 
their requests through an appropriate FAA Principal Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Standardization Branch, ANM-113.
    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.
    (d) 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.
    (e) The inspections, replacement, and installations shall be 
done in accordance with Saab Service Bulletin SAAB 340-57-027, 
Revision 01, dated June 30, 1995. 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.
    (f) This amendment becomes effective on January 27, 1997.

    Issued in Renton, Washington, on December 2, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-31111 Filed 12-18-96; 8:45 am]
BILLING CODE 4910-13-U