AD 98-20-02

This amendment adopts a new airworthiness directive (AD), applicable to certain Saab Model SAAB 2000 series airplanes, that requires 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 amendment also requires modification of the attachment bolt and attachment hole on the structural panel, which terminates the repetitive inspection requirements of this AD. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this 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 activatethe emergency MLG extension.

Final rule

98-20-02 SAAB AIRCRAFT AB: Amendment 39-10768. Docket 98-NM-63-AD.
Applicability: Model SAAB 2000 series airplanes, serial numbers -002 through -050 inclusive, and -052, -053, and -060; excluding serial number -051; 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 of this AD in accordance with Saab Service Bulletin 2000-29-007, dated April 29, 1997, is 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, or Revision 02, dated May 8, 1998.

(1) Ifno 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, or Revision 02, dated May 8, 1998. 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-116.

(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 actions shall be done in accordance with Saab Service Bulletin 2000-29-007, Revision 01, dated August 18, 1997, or Saab Service Bulletin 2000-29-007, Revision 02, dated May 8, 1998. 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, Link ping, 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 4: The subject of this AD is addressed in Swedish airworthiness directives (SAD) 1-112R1, dated August 21, 1997, and 1-112R2, dated May 8, 1998.

(f) This amendment becomes effective on October 26, 1998.

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.

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 April 21, 1998 (63 FR 19675). That action proposed to 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. That action also proposed to require modification of the attachment bolt and attachment hole on the structural panel, which would terminate the repetitive inspection requirements of this AD.

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.

The commenter, the manufacturer, indicates that it has issued Saab Service Bulletin 2000-29-007, Revision 02, dated May 8, 1998. (The proposed AD references Revision 01 of the service bulletin as the appropriate source of service information for accomplishment of the actions required by the AD.) The commenter notes that Revision 02 of the service bulletin contains no changes to compliance or technical items; it only specifies a change to the aircraft effectivity. The commenter indicates that this effectivity changes does not affect any U.S.-registered airplane.

Based on this comment, the FAA has revised this final rule to include Revision 02 of the service bulletin as an additional source of service information for accomplishment of the requirements of the AD. Additionally, the applicability of this final rule has been revised to add airplane serial number -060 (which is not on the U.S. Register), and to exclude certain airplane serial numbers, as specified in the effectivity of Revision 02 of the service bulletin.

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 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 3 Saab Model SAAB 2000 series airplanes of U.S. registry will be affected by this AD, that it will take approximately 3 work hours per airplane to accomplish the required inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the inspection on U.S. operators is estimated to be $540, or $180 per airplane, per inspection cycle.

It will take approximately 6 work hours per airplane to accomplish the required modification, at an average labor rate of $60 per work hour. Required parts will 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 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.

39.13 [Amended]2. Section 39.13 is amended by adding the following new airworthiness directive: