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 FAApublic 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 action must submit a selfaddressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 2000NM256AD.'' 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, ANM114, Attention: Rules Docket No. 2000NM256AD, 1601 Lind Avenue, SW., Renton, Washington 980554056.

Discussion

The Departmento de Aviacao Civil (DAC), which is the airworthiness authority for Brazil, notified the FAA that an unsafe condition may exist on certain EMBRAER Model EMB145 series airplanes. The DAC reported an instance of the loosening of the bolts on the hinge fittings which attach the spring tab and the servo tab to the rear spar of the elevators and indicated that the resulting loss of attachment rigidity may lead to undesirable levels of vibration. The DAC also notified the FAA that the bonding jumpers held in position by bolts on the hinge fittings may interfere with the leading edge of the spring tab.

The actions specified by the proposed AD are intended to prevent the spring tab or the servo tab from becoming disconnected, resulting in structural failure. The actions are also intended to prevent damage to the leading edge of the spring tab, which could result in loss of control of the elevator.

Explanation of Relevant Service Information

EMBRAER has issued Service Bulletin 145550009, Change No. 02, dated May 19, 2000, which describes procedures for a onetime inspection of
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the bolts on the hinge fittings that attach the spring tab and the servo tab to the rear spars of the elevators for evidence of loosening. The service bulletin also describes procedures for a onetime inspection of the region of the hinge fittings on the spring tab for interference of the bonding jumpers with the leading edge of the spring tab.

If no discrepancies are found, operators must perform followup repetitive inspections as specified in the service bulletin. If discrepancies are found, operators must perform modifications, such as replacing the bolts with improved bolts, installing washers, installing lockwire or changing its position, and changing the position of the bonding jumpers. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

The DAC issued Brazilian airworthiness directive 980502, dated May 28, 1998, which referred to Embraer Service Bulletin 145550009, initial release or further revisions approved by the Brazilian airworthiness authority.

FAA's Conclusions

This airplane model is manufactured in Brazil 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 DAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DAC, 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, except as described below.
Differences Between Proposed Rule and Service Bulletin/Brazilian Airworthiness Directive

The intervals between repetitive inspections in the proposed AD (stated in flight hours) differ from those recommended in the manufacturer's service bulletin (stated to coincide with operators' ``A'' checks). However, because regularly scheduled maintenance intervals, such as ``A'' checks, may vary from operator to operator, there would be no assurance that the inspections would be accomplished during the maximum intervals proposed by this AD. These intervals are intended to maintain an adequate level of safety within the fleet.

Another difference concerns the compliance time for accomplishment of the terminating action. The manufacturer's service bulletin recommends that, if no discrepancy is found during the initial inspection described in Part I, the terminating action described in Part II, III, or IV may be accomplished at any time, at the operator's discretion. However, the FAA has determined that requiring a specific compliance time is necessary to adequately address the identified unsafe condition. In developing an appropriate compliance time for this proposed AD, the FAA considered not only the manufacturer's recommendation, but also the degree of urgency associated with addressing the subject unsafe condition and the average utilization of the affected fleet. In light of these factors, the FAA finds a compliance time of 2,000 flight hours for accomplishing the terminating actions to be warranted, in that it represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety.

Finally, Brazilian airworthiness directive 980502 refers to EMBRAER Service Bulletin 145550009, initial release, or further revision approved by the Brazilian airworthiness authority. The proposed AD refers to EMBRAER Service Bulletin 145550009, Change No. 2, dated May 19, 2000, which includes procedures for repetitive inspections for interference between the bonding jumpers and the leading edge of the spring tab.

Cost Impact

The FAA estimates that 71 airplanes of U.S. registry would be affected by this proposed AD.

The initial inspection would take 2 work hours per airplane at an average labor rate of $60 per hour. Based on these figures, the cost impact on U.S. operators of the initial inspection (Part I) specified in the proposed AD is estimated to be $8,520, or $120 per airplane.

The cost impact on U.S. operators of followon actions is specified in the following table:
Cost of followon actions Cost of labor/ Cost of parts/ Action Work hours airplane airplane Cost/airplane Corrective action/ Part II.................. 6 $360 $71 $431 Corrective action/ Part III................. 6 360 2 362 Repetitive inspection/ Part IV.............. 3 180 0 180

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 proposed 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, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein would 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 proposal would not have federalism implications under Executive Order 13132.

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
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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 39AIRWORTHINESS 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:
Empresa Brasileira De Aeronautica S.A. (EMBRAER): Docket 2000NM 256AD.

Applicability: Model EMB145 series airplanes; serial numbers 145004 through 145103 inclusive, 145105 through 145111 inclusive, and 145113 through 145117 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 (e) 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 the spring tab or the servo tab from becoming disconnected, resulting in structural failure, and to prevent damage to the leading edge of the spring tab, which could result in loss of control of the elevator, accomplish the following:
Inspection
(a) Within 200 flight hours after the effective date of this AD, conduct a detailed visual inspection, as specified in paragraph (a)(1) or (a)(2) of this AD, as applicable, in accordance with the Accomplishment Instructions of EMBRAER Service Bulletin 145550009, Change No. 02, dated May 19, 2000.
(1) For airplanes having serial numbers 145004 through 145055 that have not been modified in accordance with EMBRAER Service Bulletin 145550009, dated April 7, 1998: Inspect the bolts attaching the spring tab and servo tab hinge fittings to the rear spar of the lefthand and righthand elevators for evidence of loosening.
(2) For airplanes having serial numbers 145004 through 145103, 145105 through 145111, and 145113 through 145117: Inspect the region of the hinge fittings on the spring tab for interference of the bonding jumper on the attaching bolts with the leading edge of the spring tab.

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.''
Modification
(b) Perform followon corrective actions, as applicable, in accordance with EMBRAER Service Bulletin 145550009, Change No. 02, dated May 19, 2000, as shown in the following table:
Table 1.Followon Corrective Actions If * * * And * * * And * * * Then * * * (1) No discrepancy is found.......... ....................... ....................... Prior to further flight, seal the bolt heads and adjacent hinge fitting surfaces. (2) Any loose bolt or any The airplanes have The airplanes have not Prior to further interference of the bonding jumpers serial numbers 145004 been modified in flight, accomplish with the leading edge of the spring through 145055, accordance with Part II of the service tab is found. inclusive. EMBRAER Service bulletin, including Bulletin 145550009, replacing bolts, dated April 7, 1998. adding washers, and changing the position of the lockwire and the bonding jumpers.
The airplanes have The airplanes have been Prior to further serial numbers 145004 modified in accordance flight, accomplish through 145055, with EMBRAER Service Part III of the inclusive, and 145056 Bulletin 145550009, service bulletin, through 145076, dated April 7, 1998. including adding inclusive. washers and changing the position of the lockwire and the bonding jumpers.
The airplanes have ....................... Prior to further serial numbers 145077 flight, accomplish through 145103, Part IV of the service inclusive; 145105 bulletin, including through 145111, adding washers and inclusive; and 145113 changing the position through 145117, of the lockwire and inclusive. the bonding jumpers. Repetitive Inspections
(c) Repeat the detailed visual inspection specified in paragraph (a) of this AD, at intervals not to exceed 400 flight hours. Terminating Action
(d) Within 2,000 flight hours from the effective date of this AD, accomplish Part II, III, or IV, as applicable, of the service bulletin.
Alternative Methods of Compliance
(e) 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, Atlanta Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through [[Page 76953]]
an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta ACO.

Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO.
Special Flight Permits
(f) Special flight permits may be issued in accordance with Secs. 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: A portion of the subject of this AD is addressed in Brazilian airworthiness directive No. 980502, dated May 28, 2000.

Issued in Renton, Washington, on December 4, 2000. Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 0031318 Filed 12700; 8:45 am] BILLING CODE 491013U

FOR FURTHER INFORMATION CONTACT Viswa Padmanabhan, Aerospace Engineer, ACE117A, FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; telephone (770) 7036049; fax (770) 7036097.