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[Federal Register: September 22, 2010 (Volume 75, Number 183)]
[Rules and Regulations]               
[Page 57666-57669]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr22se10-6]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0715; Directorate Identifier 2008-NM-211-AD; 
Amendment 39-16432; AD 2010-19-04]
RIN 2120-AA64

 
Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. 
(EMBRAER) Model EMB-120, -120ER, -120FC, -120QC, and -120RT Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above. This AD results from mandatory continuing 
airworthiness information (MCAI) originated by an aviation authority of 
another country to identify and correct an unsafe condition on an 
aviation product. The MCAI describes the unsafe condition as:

    It has been found the occurrence of corrosion on the Auxiliary 
Power Unit (APU) mounting rods that could cause the APU rod to 
break, affecting the APU support structure integrity.
* * * * *
APU support structure failure could result in loss of power of the APU 
and possible loss of control of the airplane. We are issuing this AD to 
require actions to correct the unsafe condition on these products.

DATES: This AD becomes effective October 27, 2010.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of October 27, 
2010.

ADDRESSES: You may examine the AD docket on the Internet at http://www.regulations.gov or in person at the U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC.

FOR FURTHER INFORMATION CONTACT: Todd Thompson, Aerospace Engineer, 
International Branch, ANM-116, Transport Airplane Directorate, FAA, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
227-1175; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM was published in the Federal Register on August 19, 2009 (74 
FR 41805). That NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states:

    It has been found the occurrence of corrosion on the Auxiliary 
Power Unit (APU) mounting rods that could cause the APU rod to 
break, affecting the APU support structure integrity.
* * * * *
APU support structure failure could result in loss of power of the APU 
and possible loss of control of the airplane. The required action is 
doing an external detailed inspection for corrosion of the APU 
auxiliary and center mounting rods and rod ends, and corrective actions 
if necessary. Corrective actions include removing corrosion, applying 
anticorrosive treatment, and replacing mounting rods. You may obtain 
further information by examining the MCAI in the AD docket.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comments received.

[[Page 57667]]

Request To Revise the Unsafe Condition Specified in Paragraph (e) of 
the NPRM

    EMBRAER states that the undetectable fire condition described in 
the NPRM is not verifiable since two events must happen for APU rod 
breakage to occur.
    EMBRAER states that the first event is a fire, because the rod 
breakage by itself is not enough to promote sparks or overheating of 
any kind. EMBRAER also states that the rod breakage has not been shown 
to cause leakage of APU oil in the gearbox or leakage of the fuel lines 
in the compartment. EMBRAER states both ignition sources and flammable 
fluids would be required to ignite a fire.
    EMBRAER states that for the second event to occur, a fire must 
start due to the unforeseeable scenario described previously, at which 
time damage to the fire detector, located in the vicinity of the 
combustion chamber and accessory gearbox, could occur. EMBRAER states 
that in-service experience demonstrates that the fire detector must be 
punctured or extensively crushed for it to lose its capability to 
detect a fire.
    From these statements we infer that EMBRAER requests that we revise 
paragraph (e) of the NPRM to clarify the unsafe condition. We agree 
with the scenarios EMBRAER has described previously in regards to an 
undetected fire occurring in the tail cone of the airplane. Therefore, 
we have changed the Summary section and paragraph (e) of this AD to 
state, ``APU support structure failure could result in loss of power of 
the APU and possible loss of control of the airplane.''

Request To Extend the Proposed Initial Compliance Time

    EMBRAER states that the European Aviation Safety Agency (EASA) and 
the Ag[ecirc]ncia Nacional de Avia[ccedil][atilde]o Civil (ANAC) fleets 
have accomplished their respective ADs. EMBRAER states that not one APU 
rod was removed due to moderate or heavy corrosion, with the exception 
of one event of corrosion reported at the rod terminal. EMBRAER also 
states that there is no evidence that Empresa Brasileira de Aeronautica 
S.A. (EMBRAER) Model EMB-120, -120ER, -120FC, -120QC, and -120RT 
airplanes are prone to the corrosion event.
    EMBRAER states that with the considerations stated previously, 
meaning lack of real fire in the compartment, and lack of evidence or 
reports of corrosion spreading in the current Model EMB 120 fleet, the 
initial compliance time of 500 flight hours or 2 months after the 
effective date of the AD is too conservative. EMBRAER states that this 
leads to extensive burden and labor costs on operators, and does not 
lead to a real increased margin of safety levels related to this issue. 
EMBRAER states that, according to Brazilian Airworthiness Directive 
2008-08-01, dated October 21, 2008; and EMBRAER Service Bulletin 120-
49-0023, Revision 01, dated June 30, 2008; an adequate approach could 
be taken within 1,500 flight hours or 6 months from the effective date 
of the AD, whichever occurs first.
    We infer that EMBRAER requests that we extend the proposed 
compliance time specified in the NPRM. We agree with the commenter's 
request. Since the NPRM has been published, we have determined that the 
compliance time can be extended as the inspection reports received 
provided sufficient technical information to do so. We have revised the 
initial compliance time in paragraph (f)(1) of this AD from 500 flight 
hours or 2 months after the effective date of this AD to 1,500 flight 
hours or 6 months (whichever occurs first) after the effective date of 
this AD. The revised compliance time correlates with Brazilian 
Airworthiness Directive 2008-08-01, dated October 21, 2008.

Request To Eliminate Repetitive Detailed Inspections

    EMBRAER states that the repetitive inspection interval currently 
required by the maintenance review board (MRB) report for C-Checks 
(4,000 flight cycles) states:

    Zonal Inspection Task 313-01Z Tail Cone Fairing (APU installed). 
Inspection of the APU mounting structure for condition, security of 
installation or chafing.

EMBRAER states that these findings demonstrate that the inspection 
interval in the MRB report is adequate. EMBRAER also states that few 
APU rods are reportedly replaced over time, apart from this proposed 
AD, demonstrating the MRB task is effective for the repetitive 
inspections. EMBRAER states that the repetitive detailed inspections in 
the NPRM are more restrictive than the general visual inspection 
specified in the MRB report.
    Ameriflight, LLC, states that the repetitive inspection interval of 
``not to exceed 1,500 flight hours or 6 months, whichever occurs 
first,'' is adding an additional inspection item outside the scope of 
the EMBRAER EMB120 MRB. Ameriflight, LLC, states that due to the fact 
that all of the corrosion control and corrosion prevention items 
contained in the MRB report are calendar driven, it would seem relevant 
to have the repetitive APU mounting rod corrosion inspection interval 
come due at a calendar limit rather than on an hourly basis. 
Ameriflight, LLC, also states that the MRB report contains a 12-month 
inspection for the airplane, and that the repetitive inspection of the 
APU mounting rods should be completed at a 12-month interval so it 
could be completed during the normal inspection cycle contained in the 
MRB report.
    From these statements, we infer that EMBRAER and Ameriflight, LLC, 
believe that the repetitive detailed inspections specified in the NPRM 
are more restrictive than the repetitive inspections in the MRB report, 
and that Ameriflight, LLC, believes that the repetitive inspections 
could be completed during the same inspection cycle specified in the 
MRB report.
    We agree with EMBRAER and Ameriflight, LLC, that the repetitive 
detailed inspection proposed in the NPRM is more conservative than the 
inspection in the MRB report. Since the NPRM was published, we have 
determined that the proposed repetitive inspections are no longer 
necessary as the inspection reports received provided sufficient 
technical information to remove the requirement. Therefore, the 
repetitive inspections have been removed from this AD.

Request To Extend the Compliance Time for the Reporting Requirement

    EMBRAER states that the EASA and ANAC ADs were issued in advance of 
this proposed NPRM. EMBRAER also states that the current status of U.S. 
operators that have proactively started inspecting their fleets is 46 
percent of the total fleet, meaning nearly 50 airplanes have already 
been inspected. EMBRAER states that since the proposed compliance time 
for the initial inspection specified in the NPRM is 500 flight hours, 
with the current average of 100 flight hours per month fleet usage, it 
would take more than 5 months to complete the first inspection. EMBRAER 
states that, since the results remain unchanged with time, it is 
recommended that the 30-day reporting requirement be extended to 120 
days minimum, reducing the unnecessary labor burden and processing for 
the operators.
    We disagree with extending the compliance time for submitting the 
inspection results. We also disagree that the report is an undue burden 
to the operator. A reporting requirement is instrumental in ensuring 
that we can gather as much information as possible regarding the extent 
and nature of the problem, especially when findings of corrosion are 
involved and in cases where those data might not be available through 
other established means. This information is necessary to ensure that

[[Page 57668]]

proper corrective action will be taken. We have not changed this AD 
regarding this issue.

Removal of Reporting Requirement for Light Corrosion

    Since the NPRM was issued, we have received sufficient technical 
information to remove the reporting requirement for light corrosion 
only (characterized by discoloration or pitting). We have revised 
paragraph (f)(3) of this AD to remove light corrosion from the 
reporting requirement of this AD. In addition, EMBRAER has provided us 
with an e-mail address for submission of reports. We have added that e-
mail address to paragraph (f)(3) of this AD.

Conclusion

    We reviewed the available data, including the comments received, 
and determined that air safety and the public interest require adopting 
the AD with the changes described previously. We determined that these 
changes will not increase the economic burden on any operator or 
increase the scope of the AD.

Differences Between This AD and the MCAI or Service Information

    We have reviewed the MCAI and related service information and, in 
general, agree with their substance. But we might have found it 
necessary to use different words from those in the MCAI to ensure the 
AD is clear for U.S. operators and is enforceable. In making these 
changes, we do not intend to differ substantively from the information 
provided in the MCAI and related service information.
    We might also have required different actions in this AD from those 
in the MCAI in order to follow our FAA policies. Any such differences 
are highlighted in a NOTE within the AD.

Explanation of Changes to Costs of Compliance

    Since issuance of the NPRM, we have increased the labor rate used 
in the Costs of Compliance from $80 per work-hour to $85 per work-hour. 
The Costs of Compliance information, below, reflects this increase in 
the specified hourly labor rate.

Costs of Compliance

    We estimate that this AD will affect 90 products of U.S. registry. 
We also estimate that it will take about 8 work-hours per product to 
comply with the basic requirements of this AD. The average labor rate 
is $85 per work-hour. Based on these figures, we estimate the cost of 
this AD to the U.S. operators to be $61,200, or $680 per product.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We determined that this AD will not have federalism implications 
under Executive Order 13132. This AD 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.
    For the reasons discussed above, I certify this AD:
    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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains the NPRM, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Operations office (telephone (800) 647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2010-19-04 Empresa Brasileira de Aeronautica S.A. (EMBRAER): 
Amendment 39-16432. Docket No. FAA-2009-0715; Directorate Identifier 
2008-NM-211-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective October 
27, 2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Empresa Brasileira de Aeronautica S.A. 
(EMBRAER) Model EMB-120, -120ER, -120FC, -120QC, and -120RT 
airplanes, certified in any category; as identified in EMBRAER 
Service Bulletin 120-49-0023, Revision 01, dated June 30, 2008.

Subject

    (d) Air Transport Association (ATA) of America Code 49: Airborne 
Auxiliary Power.

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:

    It has been found the occurrence of corrosion on the Auxiliary 
Power Unit (APU) mounting rods that could cause the APU rod to 
break, affecting the APU support structure integrity.

APU support structure failure could result in loss of power of the 
APU and possible loss of control of the airplane. The required 
action is doing an external detailed inspection for corrosion of the 
APU auxiliary and center mounting rods and rod ends, and corrective 
actions if necessary. Corrective actions include removing corrosion, 
applying anticorrosive treatment, and replacing mounting rods.

Actions and Compliance

    (f) Unless already done do the following actions:
    (1) Within 1,500 flight hours or 6 months after the effective 
date of this AD, whichever occurs first, do an external detailed 
inspection for corrosion of the APU, auxiliary

[[Page 57669]]

and center mounting rods, and rod ends. If any corrosion is found 
during any inspection, before further flight, do the actions 
required by paragraphs (f)(1)(i), (f)(1)(ii), and (f)(1)(iii) of 
this AD, as applicable. Do all actions required by this paragraph in 
accordance with the Accomplishment Instructions of EMBRAER Service 
Bulletin 120-49-0023, Revision 01, dated June 30, 2008.
    (i) If light corrosion (characterized by discoloration or 
pitting) is found on a mounting rod, remove the corrosion and apply 
an anticorrosive treatment.
    (ii) If moderate corrosion (characterized by surface blistering 
or evidence of scaling and flaking), or heavy corrosion 
(characterized by severe blistering exfoliation, scaling and 
flaking) is found, replace the affected mounting rod with a new 
mounting rod having the same part number.
    (iii) If any corrosion is detected on the rod ends, remove the 
corrosion and apply an anticorrosive treatment.
    (2) Accomplishing of the inspection and corrective actions 
required by paragraph (f)(1) of this AD before the effective date of 
this AD in accordance with EMBRAER Service Bulletin 120-49-0023, 
dated April 18, 2008, is acceptable for compliance with the 
corresponding requirements of paragraph (f)(1) of this AD.
    (3) For mounting rods with moderate or heavy corrosion, submit a 
report of the positive findings (including level of corrosion such 
as moderate or heavy; guidance on corrosion can be found in Chapter 
51-11-01 of the EMBRAER Corrosion Prevention Manual) of the 
inspection required by paragraph (f)(1) of this AD to Mr. Antonio 
Claret--Customer Support Group, Embraer Aircraft Holding, Inc, 276 
S.W 34th Street Fort Lauderdale, FL 33315--USA; telephone (954) 359-
3826; e-mail structure@embraer.com.br; at the applicable time 
specified in paragraph (f)(3)(i) or (f)(3)(ii) of this AD. The 
report must include the inspection results, a description of any 
discrepancies found, the airplane serial number, and the number of 
landings and flight hours on the airplane.
    (i) If the inspection was done on or after the effective date of 
this AD: Submit the report within 30 days after the inspection.
    (ii) If the inspection was accomplished prior to the effective 
date of this AD: Submit the report within 30 days after the 
effective date of this AD.

FAA AD Differences

    Note 1: This AD differs from the MCAI and/or service information 
as follows:
    (1) Although Brazilian Airworthiness Directive 2008-08-01, dated 
October 21, 2008, does not include a reporting requirement, the 
service bulletin identified in paragraph (f)(1) of this AD does 
specify reporting findings to EMBRAER. This AD requires that 
operators report the results of the inspections to EMBRAER because 
the required inspection report will help determine the extent of the 
corrosion in the affected fleet, from which we will determine if 
further corrective action is warranted. This difference has been 
coordinated with ANAC.
    (2) Brazilian Airworthiness Directive 2008-08-01, dated October 
21, 2008, allows replacement of the affected APU mounting rods by 
``new ones bearing a new P/N [part number] approved by ANAC 
[Ag[ecirc]ncia Nacional de Avia[ccedil][atilde]o Civil].'' However, 
paragraph (f)(1)(ii) of this AD requires replacing the affected 
mounting rod only with a new mounting rod having the same part 
number. Operators may request approval of an alternative method of 
compliance to install a new part number in accordance with the 
procedures specified in paragraph (g)(1) of this AD. This difference 
has been coordinated with ANAC.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, 
International Branch, ANM-116, Transport Airplane Directorate, FAA, 
has the authority to approve AMOCs for this AD, if requested using 
the procedures found in 14 CFR 39.19. Send information to ATTN: Todd 
Thompson, Aerospace Engineer, International Branch, ANM-116, 
Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; telephone (425) 227-1175; fax (425) 227-1149. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your principal maintenance inspector (PMI) or 
principal avionics inspector (PAI), as appropriate, or lacking a 
principal inspector, your local Flight Standards District Office. 
The AMOC approval letter must specifically reference this AD.
    (2) Airworthy Product: For any requirement in this AD to obtain 
corrective actions from a manufacturer or other source, use these 
actions if they are FAA-approved. Corrective actions are considered 
FAA-approved if they are approved by the State of Design Authority 
(or their delegated agent). You are required to assure the product 
is airworthy before it is returned to service.
    (3) Reporting Requirements: For any reporting requirement in 
this AD, under the provisions of the Paperwork Reduction Act (44 
U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has 
approved the information collection requirements and has assigned 
OMB Control Number 2120-0056.
    (4) Special Flight Permits: 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 airplane can be modified (if the 
operator elects to do so), except if two or more center mounting 
rods or rod ends are heavily corroded or broken, a special flight 
permit is not permitted.

Related Information

    (h) Refer to MCAI Brazilian Airworthiness Directive 2008-08-01, 
dated October 21, 2008; and EMBRAER Service Bulletin 120-49-0023, 
Revision 01, dated June 30, 2008; for related information.

Material Incorporated by Reference

    (i) You must use EMBRAER Service Bulletin 120-49-0023, Revision 
01, dated June 30, 2008, to do the actions required by this AD, 
unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Empresa Brasileira de Aeronautica S.A. (EMBRAER), Technical 
Publications Section (PC 060), Av. Brigadeiro Faria Lima, 2170-
Putim-12227-901 S[atilde]o Jose dos Campos-SP-BRASIL; telephone +55 
12 3927-5852 or +55 12 3309-0732; fax +55 12 3927-7546; e-mail 
distrib@embraer.com.br; Internet http://www.flyembraer.com.
    (3) You may review copies of the service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington. For information on the availability of this material at 
the FAA, call 425-227-1221.
    (4) You may also review copies of the service information that 
is incorporated by reference at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

    Issued in Renton, Washington, on August 30, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-22849 Filed 9-21-10; 8:45 am]
BILLING CODE 4910-13-P
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