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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. 99-NM-98-AD] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration, DOT. 

# ACTION:

Supplemental notice of proposed rulemaking; reopening of comment period. 

# SUMMARY:

                        This document revises an earlier proposed airworthiness directive (AD), applicable to certain EMBRAER Model EMB-145 series airplanes, that would have required a one-time ultrasonic inspection of the maneuvering actuator piston rod of the main landing gear (MLG) to ensure adequate wall thickness of the piston rods; and replacement of any discrepant piston rod with a new piston rod. That proposal was prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. This new action revises the proposed rule by removing all references to Change No. 01 of the referenced service bulletin. The actions specified by this new proposed AD are intended to prevent failure of the maneuvering actuator piston rod of the MLG, which would impede retraction of the MLG and                               ( print page 35591)                            consequent reduced controllability of the airplane.                     

# DATES:

Comments must be received by June 30, 2000. 

# ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-98-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via the Internet must contain “Docket No. 99-NM-98-AD” in the subject line and need not be submitted in triplicate. 

The service information referenced in the proposed rule may be obtained from Empresa Brasileira de Aeronautica S.A. (EMBRAER), P.O. Box 343-CEP 12.225, Sao Jose dos Campos SP, Brazil. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Small Airplane Directorate, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia. 

# FOR FURTHER INFORMATION CONTACT:

Satish Lall, Aerospace Engineer, Airframe and Propulsion Branch, ACE-117A, FAA, Small Airplane Directorate, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; telephone (770) 703-6082; fax (770) 703-6097. 

# 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. 

Submit comments using the following format: 
    - Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
    - For each issue, state what specific change to the proposed AD is being requested.
    - Include justification ( e.g. , reasons or data) for each request.                 

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 postcard on which the following statement is made: “Comments to Docket Number 99-NM-98-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. 99-NM-98-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. 

## Discussion 

                    A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to add an airworthiness directive (AD), applicable to certain EMBRAER Model EMB-145 series airplanes, was published as a notice of proposed rulemaking (NPRM) in the                     **Federal Register**                     on May 7, 1999 (64 FR 24545). That NPRM would have required a one-time ultrasonic inspection of the maneuvering actuator piston rod of the main landing gear (MLG) to ensure adequate wall thickness of the piston rods; and replacement of any discrepant piston rod with a new piston rod. That NPRM was prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. That condition, if not corrected, could result in failure of the maneuvering actuator piston rod of the MLG, which would impede retraction of the MLG and consequent reduced controllability of the airplane.                 

## Actions Since Issuance of Previous Proposal 

Since the issuance of that NPRM, the FAA recognized that it inadvertently specified EMBRAER Service Bulletin 145-32-0031, Change No. 01, dated December 8, 1998, as an appropriate source of service information for accomplishing the requirements of the NPRM and for determining the affected airplanes. The Departmento de Aviacao Civil (DAC), which is the airworthiness authority for Brazil, only classified Change No. 02 of EMBRAER Service Bulletin 145-32-0031, dated February 12, 1999, as mandatory. Change No. 02 of the service bulletin differs from Change No. 01 in that it incorporates additional affected actuator part numbers and serial numbers. Therefore, the FAA has removed all references to Change No. 01 of the subject service bulletin from the proposed AD. 

## Conclusion 

Since this change expands the scope of the originally proposed rule, the FAA has determined that it is necessary to reopen the comment period to provide additional opportunity for public comment. 

## Cost Impact 

The FAA estimates that 33 EMBRAER Model EMB-145 series airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 1 work hour per airplane to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $1,980, or $60 per airplane. 

The cost impact figure discussed above is 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 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 Flexibility Act. A copy of the draft regulatory evaluation prepared for this                           ( print page 35592)                        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. 

§ 39.13 

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

**Empresa Brasileira de Aeronautica S.A. (EMBRAER):**                                 Docket 99-NM-98-AD.                             

*Applicability:*                                 Model EMB-145 series airplanes, equipped with main landing gear maneuvering actuators, part and serial numbers as listed in EMBRAER Service Bulletin 145-32-0031, Change No. 02, dated February 12, 1999; 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 (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 failure of the maneuvering actuator piston rod of the main landing gear (MLG), which would impede retraction of the MLG and consequent reduced controllability of the airplane; accomplish the following: 

## Ultrasonic Inspection and Replacement, If Necessary 

(a) Within the next 100 landings after the effective date of this AD, perform an ultrasonic inspection of the maneuvering actuator piston rods of the MLG to ensure adequate wall thickness of the piston rods, in accordance with EMBRAER Service Bulletin 145-32-0031, Change No. 02, dated February 12, 1999. 

(1) If the thickness of any measurement point in any piston rod is greater than 2.0 mm (.079 inch), no further action is required by this AD. 

(2) If the thickness of any measurement point in any piston rod is from 1.5 mm (.059 inch) to 2.0 mm (.079 inch): Within 500 landings after the effective date of this AD, replace the piston rod with a new rod having the correct part number as specified in the service bulletin. 

(3) If the thickness of any measurement point in any piston rod is less than 1.5 mm (.059 inch): Within 50 landings after the effective date of this AD, replace the piston rod with a new rod having the correct part number as specified in the service bulletin. 

## Alternative Methods of Compliance 

(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, Atlanta Aircraft Certification Office (ACO), 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, Atlanta ACO. 

# Note 2:

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 

(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. 

# Note 3:

The subject of this AD is addressed in Brazilian airworthiness directive 98-09-01 R1, dated March 15, 1999.

Issued in Renton, Washington on May 17, 2000. 

Donald L. Riggin, 

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. 

[FR Doc. 00-14019 Filed 6-2-00; 8:45 am] 

BILLING CODE 4910-13-U