[Federal Register Volume 69, Number 66 (Tuesday, April 6, 2004)]
[Proposed Rules]
[Pages 17993-17996]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-7709]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-346-AD]
RIN 2120-AA64


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).

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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: 
[email protected]. 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

[[Page 17994]]

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

[[Page 17995]]

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.


Sec.  39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-12845 (67 FR 
52398, August 12, 2002), and by adding a new airworthiness directive 
(AD), to read as follows:

Empresa Brasileira de Aeronautica S.A. (EMBRAER): Docket 2002-NM-
346-AD. Supersedes AD 2002-16-06, Amendment 39-12845.
    Applicability: Model EMB-135BJ series airplanes, as listed in 
EMBRAER Service Bulletin 145LEG-49-0001, Change 01, dated August 29, 
2002; and Model EMB-135 and -145 series airplanes, as listed in 
EMBRAER Service Bulletin 145-49-0021, Change 03, dated September 12, 
2003; certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent separation of the aft baffle assembly from the 
auxiliary power unit (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, accomplish the following:

Modification

    (a) For airplanes that have incorporated EMBRAER Alert Service 
Bulletin 145-49-A021, Change 01, dated May 13, 2003: Within 1,500 
flight hours after the effective date of this AD; install a spacer 
and bolts (including torquing the bolts) in the APU exhaust silencer 
assembly per the Accomplishment Instructions of EMBRAER Service 
Bulletin 145LEG-49-0001, Change 01, dated August 29, 2002, (for 
Model EMB-135BJ series airplanes); or Part II of the Accomplishment 
Instructions of EMBRAER Service Bulletin 145-49-0021, Change 03, 
dated September 12, 2003, (for Model EMB -135 and -145 series 
airplanes); as applicable.

Reidentification of Modified Part

    (b) For airplanes that have incorporated EMBRAER Alert Service 
Bulletin 145-49-A021, Change 01, dated May 13, 2003: After 
accomplishment of the modification required by paragraph (a) of this 
AD; before further flight, change the part number of the modified 
APU exhaust silencer assembly from 4503801B to 4503801C per the 
Accomplishment Instructions of EMBRAER Service Bulletin 145LEG-49-
0001, Change 01, dated August 29, 2002; or Part II of the 
Accomplishment Instructions of EMBRAER Service Bulletin 145-49-0021, 
Change 03, dated September 12, 2003; as applicable.

Inspections

    (c) For airplanes that have not incorporated EMBRAER Alert 
Service Bulletin 145-49-A021, Change 01, dated May 13, 2003: Within 
500 flight hours or 3 months after the effective date of this AD, 
whichever is first; do a one-time general visual inspection of the 
APU exhaust silencer to determine if the aft baffle is flush with 
the end of the cylindrical portion, and an inspection of the 
movement of the cylindrical portion of the APU exhaust silencer 
shell assembly, per the Accomplishment Instructions of EMBRAER 
Service Bulletin 145LEG-49-0001, Change 01, dated August 29, 2002; 
or Part I of the Accomplishment Instructions of EMBRAER Service 
Bulletin 145-49-0021, Change 03, dated September 12, 2003; as 
applicable.
    (1) If the APU exhaust silencer assembly passes the inspections: 
Do the actions in paragraph (d) of this AD.
    (2) If the APU exhaust silencer assembly does not pass one or 
both inspections: Before further flight, secure or remove the 
affected parts from the silencer, and placard the APU as 
``Inoperative'' per the Accomplishment Instructions of the 
applicable service bulletin. No further action is required unless 
the APU is reactivated. To reactivate the APU: Before further 
flight, do the actions required by paragraph (e) of this AD.

    Note 1: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made from within 
touching distance unless otherwise specified. A mirror may be 
necessary to enhance visual access to all exposed surfaces in the 
inspection area. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or droplight and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''

Repetitive Inspections

    (d) For airplanes that have not incorporated EMBRAER Alert 
Service Bulletin 145-49-A021, Change 01, dated May 13, 2003: After 
doing the inspections required by paragraph (c) of this AD, before 
further flight; do a mechanical integrity

[[Page 17996]]

inspection of the APU exhaust silencer assembly per the 
Accomplishment Instructions of EMBRAER Service Bulletin 145LEG-49-
0001, Change 01, dated August 29, 2002; or Part I of the 
Accomplishment Instructions of EMBRAER Service Bulletin 145-49-0021, 
Change 03, dated September 12, 2003; as applicable.
    (1) If the APU exhaust silencer assembly passes the inspection 
required by paragraph (d) of this AD: Do the same steps for the 
mechanical integrity inspection required by paragraph (d) of this AD 
in a counter-clockwise direction, per the Accomplishment 
Instructions of the applicable service bulletin. Repeat the 
inspections required by paragraphs (d) and (d)(1) of this AD 
thereafter at intervals not to exceed 500 flight hours or 3 months, 
whichever is first. The inspections may be repeated up to two times 
before accomplishment of the requirements of paragraph (e) of this 
AD.
    (2) If the APU exhaust silencer assembly does not pass the 
inspection required by paragraph (d) of this AD: Before further 
flight, disassemble the APU exhaust silencer assembly or placard the 
APU as ``Inoperative'' per the Accomplishment Instructions of the 
applicable service bulletin. No further action is required unless 
the APU is reactivated. To reactivate the APU: Before further 
flight, do the actions required by paragraph (e) of this AD.

Modification/Terminating Action

    (e) For airplanes that have not incorporated EMBRAER Alert 
Service Bulletin 145-49-A021, Change 01, dated May 13, 2003: Within 
1,500 flight hours or 12 months after the effective date of this AD, 
whichever is first, except as provided by paragraphs (c)(2) and 
(d)(2) of this AD; do all of the applicable actions per the 
Accomplishment Instructions of EMBRAER Service Bulletin 145LEG-49-
0001, Change 01, dated August 29, 2002; or Part I of the 
Accomplishment Instructions of EMBRAER Service Bulletin 145-49-0021, 
Change 03, dated September 12, 2003; as applicable. This constitutes 
terminating action for the repetitive inspections required by 
paragraph (d) of this AD.

Reidentification of Modified Part

    (f) For airplanes that have not incorporated EMBRAER Alert 
Service Bulletin 145-49-A021, Change 01, dated May 13, 2003: After 
accomplishment of the modification required by paragraph (e) of this 
AD; before further flight, change the part number of the modified 
APU exhaust silencer assembly from 4503801B to 4503801C per the 
Accomplishment Instructions of EMBRAER Service Bulletin 145LEG-49-
0001, Change 01, dated August 29, 2002; or Part I of the 
Accomplishment Instructions of EMBRAER Service Bulletin 145-49-0021, 
Change 03, dated September 12, 2003; as applicable.

Credit for Actions Previously Accomplished

    (g) Accomplishment of the specified actions before the effective 
date of this AD per EMBRAER Service Bulletin 145-49-0021, Change 02, 
dated November 12, 2002, is considered acceptable for compliance 
with the applicable requirements of paragraphs (a), (b), (c), (d), 
(e), and (f) of this AD.

Parts Installation

    (h) As of the effective date of this AD, no person may install 
on any airplane an APU exhaust silencer having P/N 4503801B.

Submission of Information Not Required

    (i) Although the service bulletins referenced in this AD specify 
to submit information to the manufacturer, this AD does not include 
such a requirement.

Alternative Methods of Compliance

    (j) In accordance with 14 CFR 39.19, the Manager, International 
Branch, ANM-116, Transport Airplane Directorate, FAA, is authorized 
to approve alternative methods of compliance for this AD.

    Note 2: The subject of this AD is addressed in Brazilian 
airworthiness directive 2002-05-01R2, dated January 6, 2003.


    Issued in Renton, Washington, on March 30, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-7709 Filed 4-5-04; 8:45 am]
BILLING CODE 4910-13-P