[Federal Register Volume 63, Number 76 (Tuesday, April 21, 1998)]
[Proposed Rules]
[Pages 19675-19677]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-10473]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-63-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 adoption of a new airworthiness 
directive (AD) that is applicable to certain Saab Model SAAB 2000 
series airplanes. This proposal would require repetitive inspections to 
detect chafing of the hydraulic pipe on the emergency uplock release 
system of the main landing gear (MLG); testing of the hydraulic pipe 
for leaks, if necessary; and repair of the hydraulic pipe, if 
necessary. This proposal also would require modification of the 
attachment bolt and attachment hole on the structural panel, which 
would terminate the repetitive inspection requirements of this AD. This 
proposal is prompted by issuance of mandatory continuing airworthiness 
information by a foreign civil airworthiness authority. The actions 
specified by the proposed AD are intended to prevent chafing between 
the hydraulic pipe on the emergency uplock release system of the MLG 
and an attachment bolt on a structural panel, which could result in 
rupture of the hydraulic pipe, loss of hydraulic pressure, and 
consequent inability to activate the emergency MLG extension.

DATES: Comments must be received by May 21, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-63-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal 
holidays.
    The service information referenced in the proposed rule may be 
obtained from Saab Aircraft AB, SAAB Aircraft Product Support, S-
581.88, Linkoping, Sweden. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

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:

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 notice may be changed in 
light of the comments received.
    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 notice must submit a self-addressed, 
stamped

[[Page 19676]]

postcard on which the following statement is made: ``Comments to Docket 
Number 98-NM-63-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. 98-NM-63-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Luftfartsverket (LFV), which is the airworthiness authority for 
Sweden, notified the FAA that an unsafe condition may exist on certain 
Saab Model SAAB 2000 series airplanes. The LFV advises that it has 
received reports indicating that interference may exist between the 
hydraulic pipe on the emergency uplock release system of the main 
landing gear (MLG) and an attachment bolt on a structural panel. 
Investigation has revealed that the design of the emergency uplock 
release system on certain SAAB 2000 series airplanes causes the 
hydraulic pipe and the attachment bolt to be susceptible to this type 
of interference. Such interference may cause chafing of the hydraulic 
pipe. This condition, if not corrected, could result in rupture of the 
hydraulic pipe, loss of hydraulic pressure, and consequent inability to 
activate the emergency MLG extension.

Explanation of Relevant Service Information

    Saab has issued Service Bulletin 2000-29-007, Revision 01, dated 
August 18, 1997, which describes procedures for repetitive visual 
inspections to detect chafing of the hydraulic pipe on the emergency 
uplock release system of the MLG; testing of the hydraulic pipe for 
leaks, if necessary; and repair of the hydraulic pipe, if necessary. 
The service bulletin also describes procedures for modification of the 
attachment bolt and attachment hole on the structural panel, which 
would eliminate the need for the repetitive inspections described in 
the service bulletin. Accomplishment of the actions specified in the 
service bulletin is intended to adequately address the identified 
unsafe condition. The LFV classified this service bulletin as mandatory 
and issued Swedish airworthiness directive (SAD) 1-112R1, dated August 
21, 1997, in order to assure 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 
Sec. 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. The FAA has 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 require accomplishment of 
the actions specified in the service bulletin described previously.

Cost Impact

    The FAA estimates that 3 airplanes of U.S. registry would be 
affected by this proposed AD. It would take approximately 3 work hours 
per airplane to accomplish the proposed 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 
$540, or $180 per airplane.
    It would take approximately 6 work hours per airplane to accomplish 
the proposed modification, at an average labor rate of $60 per work 
hour. Required parts would be supplied by the manufacturer at no cost 
to the operators. Based on these figures, the cost impact of the 
modification required by this AD on U.S. operators is estimated to be 
$1,080, or $360 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.

Regulatory Impact

    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    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 adding the following new 
airworthiness directive:

SAAB Aircraft AB: Docket 98-NM-63-AD.

    Applicability: Model SAAB 2000 series airplanes, serial numbers 
-002 through -059 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 (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.

    Note 2: Accomplishment of the actions required by this AD prior 
to the effective date

[[Page 19677]]

of this AD in accordance with Saab Service Bulletin 2000-29-007, 
dated April 29, 1997, are considered acceptable for compliance with 
the applicable actions specified in this AD.

    To prevent chafing between the hydraulic pipe on the emergency 
uplock release system of the main landing gear (MLG) and an 
attachment bolt on a structural panel, which could result in rupture 
of the hydraulic pipe, loss of hydraulic pressure, and consequent 
inability to activate the emergency MLG extension, accomplish the 
following:
    (a) Within 300 flight hours after the effective date of this AD, 
perform a visual inspection to detect chafing of the hydraulic pipe 
on the emergency uplock release system of the MLG, in accordance 
with Saab Service Bulletin 2000-29-007, Revision 01, dated August 
18, 1997.
    (1) If no chafing is detected, repeat the visual inspection 
thereafter at intervals not to exceed 300 flight hours.
    (2) If any chafing is detected, prior to further flight, perform 
a test of the hydraulic pipe to detect leaks in accordance with the 
service bulletin.
    (i) If no leaking is detected, repeat the actions required by 
paragraph (a) of this AD thereafter at intervals not to exceed 300 
flight hours.
    (ii) If any leaking is detected, prior to further flight, repair 
the hydraulic pipe and accomplish paragraph (b) of this AD, in 
accordance with the service bulletin.
    (b) Within 900 flight hours after the effective date of this AD, 
modify the attachment bolt and attachment hole on the structural 
panel, in accordance with Saab Service Bulletin 2000-29-007, 
Revision 01, dated August 18, 1997. Accomplishment of this 
modification constitutes terminating action for the repetitive 
inspection requirements of 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, 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-216.

    (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.

    Note 4: The subject of this AD is addressed in Swedish 
airworthiness directive (SAD) 1-112R1, dated August 21, 1997.

    Issued in Renton, Washington, on April 15, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-10473 Filed 4-20-98; 8:45 am]
BILLING CODE 4910-13-U