AD 2001-26-18

This amendment adopts a new airworthiness directive (AD), applicable to certain Dornier Model 328-300 series airplanes, that requires, for certain airplanes, a one-time torque test (inspection) of the attachment bolts of the forward engine mount vibration isolators to determine if the bolts are adequately torqued, and corrective action, if necessary. For all airplanes, this amendment prohibits installation of an attachment bolt on the forward engine mount vibration isolators, unless the attachment bolt is torqued within certain limits. These actions are necessary to prevent failure of the engine mount, which could result in separation of the engine from the airplane. This action is intended to address the identified unsafe condition.

Final rule

2001-26-18 Dornier Luftfahrt GMBH: Amendment 39-12584. Docket 2001-NM-174-AD.

Applicability: Model 328-300 series airplanes, on which a forward engine mount vibration isolator has been removed or reinstalled since the date of manufacture of the airplane, 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 (d) 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 failure of the engine mount, which could result in separation of the engine from the airplane, accomplish the following:

One-Time Inspection

(a) For airplanes on which a forward engine mount vibration isolator has been removed or reinstalled prior to the effective date of this AD: Within 2,500 flight cycles after the first removal or reinstallation of a forward engine mount vibration isolator, or within 30 days after the effective date of this AD, whichever comes later, do a one-time torque test (inspection) of the attachment bolts of the forward engine mount vibration isolators on the left- and right-hand sides of the airplane to determine if the bolts are adequately torqued, according to Dornier Service Bulletin SB-328J-71-109, dated March 26, 2001, including Dornier 328JET Aircraft Maintenance Manual (AMM) Temporary Revision (TR) 71-130, dated March 8, 2001.

Replacement of Bolts

(b) During the inspection required by paragraph (a) of this AD, if the torque value of any attachment bolt is found to be outside the limits specified in Dornier Service Bulletin SB-328J-71-109, dated March 26, 2001, including Dornier 328JET AMM TR 71-130, dated March 8, 2001: Before further flight, do all actions associated with replacing all bolts on the vibration isolator on which the improperly torqued bolt was found (including performing a detailed visual inspection to determine the condition of components of the vibration isolator and replacement of any damaged components with new components, removing the existing bolts and washers that attach the forward engine mount vibration isolators to the engine, installing new bolts to reattach the forward engine mount vibration isolators to the engine, and torquing the new bolts to adequate torque values), according to the service bulletin.

Note 2: For the purposes of this AD, a detailed visual inspection is defined as: ``An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.''

Torque Requirements

(c) For all airplanes: As of the effective date of this AD, no one may install an attachment bolt on the forward engine mount vibration isolators on any airplane, unless the attachment bolt is torqued within the limits specified in Dornier 328JET AMM TR 71-130, dated March 8, 2001.

Alternative Methods of Compliance

(d) 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, Transport Airplane Directorate, FAA. 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.

Special Flight Permits

(e) 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.

Incorporation by Reference

(f) The actions shall be done in accordance with Dornier Service Bulletin SB-328J-71-109, dated March 26, 2001, including Dornier 328JET Aircraft Maintenance Manual Temporary Revision 71-130, dated March 8, 2001. 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 FAIRCHILD DORNIER, DORNIER Luftfahrt GmbH, P.O. Box 1103, D-82230 Wessling, Germany. 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 German airworthiness directive 2001-163, dated June 14, 2001.

Effective Date

(g) This amendment becomes effective on February 8, 2002.

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 Dornier Model 328-300 series airplanes was published in the Federal Register on September 14, 2001 (66 FR 47901). That action proposed to require, for certain airplanes, a one-time torque test (inspection) of the attachment bolts of the forward engine mount vibration isolators to determine if the bolts are adequately torqued, and corrective action, if necessary. For all airplanes, that action also proposed to prohibit installation of an attachment bolt on the forward engine mount vibration isolators, unless the attachment bolt is torqued within certain limits.

Comments

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

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

Cost Impact

The FAA estimates that 36 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 $4,320, 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. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, ortime necessitated by other administrative actions.

Regulatory Impact

The regulations adopted herein will not have a substantial direct effect 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, it is determined that this final rule does not have federalism implications under Executive Order 13132.

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 theRules 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: