AD Amdt-39-10401

[Federal Register Volume 63, Number 53 (Thursday, March 19, 1998)]
[Rules and Regulations]
[Pages 13332-13333]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 98-6761]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-289-AD; Amendment 39-10401; AD 98-06-23]
RIN 2120-AA64


Airworthiness Directives; Saab Model SAAB 2000 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Saab Model SAAB 2000 series airplanes, that 
requires application of sealant to the auxiliary power unit (APU) 
firezone bulkhead. This amendment is prompted by issuance of mandatory 
continued airworthiness information by a foreign civil airworthiness 
authority. The actions specified by this AD are intended to prevent 
hazardous amounts of flame, fuel, and vapor from entering compartments 
outside the fire zone due to unsealed openings in the firezone 
bulkhead, which could result in a fire outside the APU firezone 
compartment.

DATES: Effective April 23, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of April 23, 1998.

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 2000 
series airplanes was published in the Federal Register on December 18, 
1997 (62 FR 66315). That action proposed to require application of 
sealant to the auxiliary power unit (APU) firezone bulkhead.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the single comment received.

Request To Revise Description of the Addressed Unsafe Condition

    One commenter notes that the description of the addressed unsafe 
condition that appeared in the proposal states, in part, `` * * * to 
prevent hazardous amounts of flame, fuel, and vapor from entering the 
passenger compartments * * *.'' The commenter states that there are 
other compartments between the APU firezone compartments and the 
passenger compartment; the actual design makes it unlikely that flames, 
fuel, or vapor will enter the passenger compartment due to unsealed 
openings in the firezone bulkhead. The commenter suggests that a more 
accurate description of the unsafe condition would be ``* * * to 
prevent hazardous amounts of flame, fuel, and vapor from entering 
compartments outside the fire zone * * *. ''
    The FAA concurs that the commenter's proposed wording is a more 
accurate statement of the unsafe condition. The FAA has revised this 
final rule accordingly.

Conclusion

    After careful review of the available data, including the comment 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the change previously 
described. 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 3 Model SAAB 2000 series airplanes of U.S. 
registry will be affected by this AD, that it will take approximately 2 
work hours per airplane to accomplish the required actions, and that 
the average labor rate is $60 per work hour. Based on these figures, 
the cost impact of the AD on U.S. operators is estimated to be $360, or 
$120 per airplane.
    The cost impact figure discussed above is 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:

98-06-23  Saab Aircraft AB: Amendment 39-10401. Docket 97-NM-289-AD.

    Applicability: Model SAAB 2000 series airplanes, serial numbers 
-004 through -040 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

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accordance with paragraph (b) 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 hazardous amounts of flame, fuel, and vapor from 
entering compartments outside the fire zone due to unsealed openings 
in the firezone bulkhead, which could result in an uncontrollable 
fire outside the auxiliary power unit (APU) firezone compartment, 
accomplish the following:
    (a) Within 400 flight hours or 2 months after the effective date 
of this AD, whichever occurs later, apply sealant to the APU 
firezone bulkhead, in accordance with Saab Service Bulletin 2000-53-
024, dated December 2, 1996.
    (b) 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, 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, International 
Branch, ANM-116.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (c) 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.
    (d) The actions shall be done in accordance with Saab Service 
Bulletin 2000-53-024, dated December 2, 1996. 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 3: The subject of this AD is addressed in Swedish 
airworthiness directive SAD No. 1-105, dated December 4, 1996.

    (e) This amendment becomes effective on April 23, 1998.

    Issued in Renton, Washington, on March 10, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-6761 Filed 3-18-98; 8:45 am]
BILLING CODE 4910-13-U