Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-135 and -145 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain EMBRAER Model EMB-135 and -145 series airplanes, that currently requires determining whether a defective auxiliary power unit (APU) exhaust silencer is installed on the airplane; and corrective actions if necessary. For certain airplanes, this action would require modification of the APU exhaust silencer, and reidentification of the part number for the APU exhaust silencer once the modification is accomplished. For certain other airplanes, this action would require repetitive inspections to determine the structural integrity of the APU exhaust silencer; corrective actions, if necessary; eventual modification of the APU exhaust silencer, which terminates the repetitive inspections; and reidentification of the part number for the APU exhaust silencer once the modification is accomplished. This action would also add airplanes to the applicability of the existing AD. The actions specified by the proposed AD are intended to prevent separation of the aft baffle assembly from the APU exhaust silencer and consequent separation of the assembly from the airplane, which could cause damage to other airplanes during takeoff and landing operations, or injury to people on the ground. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by May 6, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-346-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 be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-346-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

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.

FOR FURTHER INFORMATION CONTACT:

Todd Thompson, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-1175; 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 action 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 action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2002-NM-346-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. 2002-NM-346-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On August 1, 2002, the FAA issued AD 2002-16-06, amendment 39-12845 (67 FR 52398, August 12, 2002), applicable to certain EMBRAER Model EMB-135 and -145 series airplanes. That AD requires determining whether a defective auxiliary power unit (APU) exhaust silencer is installed on the airplane; and corrective actions, if necessary. That action was prompted by a report that the aft baffle assembly separated from the shell assembly of an APU exhaust silencer having part number 4503801B. The requirements of that AD are intended to prevent separation of the aft baffle assembly from the APU exhaust silencer and consequent separation of the assembly from the airplane, which could cause damage to other airplanes during takeoff and landing operations, or injury to people on the ground.

Actions Since Issuance of Previous Rule

Since the issuance of that AD, the Departmento de Aviacao Civil (DAC), which is the airworthiness authority for Brazil, issued a revised airworthiness directive which adds airplanes to the applicability of the existing Brazilian airworthiness directive, new repetitive inspections, and additional modifications; and allows up to two repetitive inspections before accomplishment of the modifications that terminate the repetitive inspections.

Explanation of Relevant Service Information

EMBRAER has issued Service Bulletin 145-49-0021, Change 03, dated September 12, 2003 (for Model EMB-135 and -145 series airplanes). For airplanes listed in the effectivity for Part I of the service bulletin, the procedures include a visual inspection of the APU exhaust silencer to determine if the aft baffle is flush with the end of the cylindrical portion, an inspection of the movement of the cylindrical portion of the APU exhaust silencer shell assembly, modification of the APU exhaust silencer assembly by spot-welding and installing bolts (including torquing the bolts) and a spacer, and reidentification of the modified APU exhaust silencer assembly with a new part number. For airplanes listed in the effectivity for Part II of the service bulletin, the procedures include modifying the APU exhaust silencer assembly by installing a spacer and bolts (including torquing the bolts), and reidentifying the modified APU exhaust silencer assembly with a new part number. Both Part I and Part II of the EMBRAER service bulletin request that operators submit a form notifying the manufacturer when the actions in the service bulletin have been accomplished.

Also, both Part I and Part II of the service bulletin reference Hamilton Sundstrand Service Bulletin SB-4503801-49-3, Revision 02, dated July 19, 2002, as an additional source of service information for inspection and modification of the APU exhaust silencer assembly. The Hamilton Sundstrand bulletin is incorporated into the EMBRAER service bulletin.

EMBRAER has also issued Service Bulletin 145LEG-49-0001, Change 01, dated August 29, 2002 (for Model EMB-135BJ series airplanes). This service bulletin describes procedures for inspecting the APU exhaust silencer assembly, modifying the APU exhaust silencer assembly by installing fasteners and a spacer, and reidentifying the modified APU exhaust silencer assembly with a new part number. The service bulletin requests that operators submit a form notifying the manufacturer when the actions in the service bulletin have been accomplished. The service bulletin references Hamilton Sundstrand Service Bulletin SB-4503801-49-3, Revision 02, dated July 19, 2002, as an additional source of service information for inspection and modification of the APU exhaust silencer assembly. The Hamilton Sundstrand service bulletin is incorporated into the EMBRAER service bulletin.

The DAC classified the EMBRAER service bulletins as mandatory and issued Brazilian airworthiness directive 2002-05-01R2, dated January 6, 2003, to ensure the continued airworthiness of these airplanes in Brazil.

FAA's Conclusions

These airplane models are manufactured in Brazil and are type certificated for operation in the United States under the provisions of section 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 us informed of the situation described above. We have 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 AD

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 supersede AD 2002-16-06. For certain airplanes, the proposed AD would require modification of the APU exhaust silencer, and reidentification of the part number for the APU exhaust silencer once the modification is accomplished. For certain other airplanes, the proposed AD would require repetitive inspections to determine the structural integrity of the APU exhaust silencer; corrective actions, if necessary; modification of the APU exhaust silencer, which terminates the repetitive inspections; and reidentification of the part number for the APU exhaust silencer once the modification is accomplished. The proposed AD would also add airplanes to the applicability of the existing AD. The actions would be required to be accomplished in accordance with the applicable service bulletin described previously, except as described below.

Differences Between the Proposed AD and Service Information

Although the Accomplishment Instructions of the service bulletins specify to report accomplishment of the service bulletins to the manufacturer, this proposed AD does not require that action.

Cost Impact

There are approximately 394 airplanes of U.S. registry that would be affected by this proposed AD.

The proposed repetitive inspections specified in Part I of EMBRAER Service Bulletin 145-49-0021, Change 03, dated September 12, 2003; and EMBRAER Service Bulletin145LEG-49-0001, Change 01, dated August 29, 2002; would take approximately 1 work hour per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed repetitive inspections on U.S. operators is estimated to be $65 per airplane, per inspection cycle.

The proposed modification, including the part number reidentification, specified in Part I of EMBRAER Service Bulletin 145-49-0021, Change 02; and EMBRAER Service Bulletin145LEG-49-0001, Change 01; would take approximately 4 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Required parts would be supplied by the part manufacturer at no cost to operators. Based on these figures, the cost impact of the proposed modification is estimated to be $102,440, or $260 per airplane.

The proposed modification, including the part number reidentification, specified in Part II of EMBRAER Service Bulletin 145-49-0021, Change 03, would take approximately 1 work hour per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed modification is estimated to be $65 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or proposed 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, 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 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.