[Federal Register Volume 62, Number 14 (Wednesday, January 22, 1997)]
[Rules and Regulations]
[Pages 3209-3211]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-1439]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-201-AD; Amendment 39-9891; AD 96-25-06 R1]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.


[[Page 3210]]


ACTION: Final rule; correction.

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SUMMARY: This document corrects information in an existing 
airworthiness directive (AD), applicable to certain Saab Model SAAB 
SF340A and SAAB 340B series airplanes, that currently 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 action corrects 
information concerning the terminating action for the requirements of 
the AD. This action is necessary to ensure that operators are not 
required to perform additional actions unnecessarily after modifying 
their airplanes.

DATES: Effective January 27, 1997.
    The incorporation by reference of certain publications listed in 
the regulations was previously approved by the Director of the Federal 
Register as of January 27, 1997 (61 FR 66885, December 19, 1996).

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: On December 2, 1996, the FAA issued AD96-25-
06, amendment 39-9848 (61 FR 66885, December 19, 1996). That AD 
requires repetitive 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. That AD 
action was 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 required by 
that 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.

Explanation of Necessary Correction of AD

    Recently, the FAA has become aware of the fact that, as AD 96-25-06 
is currently worded, certain of the terminating action provisions in it 
are not clear.
    Specifically, paragraph (a) of the AD requires repetitive visual 
inspections to detect cracking of the forward and aft attachment lugs 
of the flap fittings at wing station (WS) 123.38. Paragraph (a)(2) of 
the AD states that, if any cracking is found during one of these visual 
inspections, operators must immediately replace the flap fittings with 
new improved flap fittings and install improved bushings. This 
installation is specified as Modification 2628--Part 3 in the 
Accomplishment Instructions of Saab Service Bulletin SAAB 340-57-027, 
Revision 01, dated June 30, 1995. Paragraph (a)(2) of the AD then 
states, ``After this modification is accomplished, no further action is 
required by this paragraph.''
    While it is correct that the operators who accomplished that 
modification would not have to continue to perform the visual 
inspections required by paragraph (a), they also would not have to 
accomplish any other portion of the AD. In other words, that 
modification constitutes terminating action for the requirements of the 
AD, not merely the requirements of paragraph (a).
    While AD 96-25-06 may have been unclear on this point, it was the 
FAA's intent that the modification be considered terminating action for 
the requirements of the AD. Additionally, the referenced Saab service 
bulletin (340-57-027), as well as the parallel Swedish airworthiness 
directive (SAD No. 1-072), indicate that no further work is required of 
operators who accomplish Modification 2628--Part 3.

Corrective Action Taken

    The FAA has determined that it is appropriate to take action to 
correct paragraph (a)(2) of AD 96-25-06 to state: ``After this 
modification is accomplished, no further action is required by this 
AD.'' The FAA finds this correction is necessary in order to prevent 
operators from having to perform additional and unnecessary work on 
these airplanes.
    Action is taken herein to correct the error and to correctly add 
the AD as an amendment to section 39.13 of the Federal Aviation 
Regulations (14 CFR 39.13). The effective date of the AD remains 
January 27, 1997.
    The AD is being reprinted in its entirety, below, for the 
convenience of affected operators.

No Need for Additional Notice and Public Comment

    Since this action only clarifies the intent of a provision of an 
AD, and relieves affected operators from having to perform what could 
be additional and unnecessary work, it has no adverse economic impact 
and imposes no additional burden on any person. Therefore, notice and 
public procedures hereon are unnecessary.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Correction

    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 removing amendment 39-9848 (61 FR 
66885, December 19, 1996), and by adding a new airworthiness directive 
(AD), amendment 39-9891, to read as follows:

96-25-06 R1 SAAB Aircraft AB: Amendment 39-9891. Docket 95-NM-201-
AD. Revises AD 96-25-06, amendment 39-9848.

    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 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

[[Page 3211]]

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 AD.
    (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, 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, as of January 27, 1997 (61 
FR 66885, December 19, 1996). 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 is effective January 27, 1997.

    Issued in Renton, Washington, on January 14, 1997.
S. R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-1439 Filed 1-21-97; 8:45 am]
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