Airworthiness Directives; EMBRAER Model EMB-120, -120ER, -120FC, -120QC, and -120RT Airplanes

[Federal Register Volume 73, Number 11 (Wednesday, January 16, 2008)]
[Rules and Regulations]
[Pages 2793-2795]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-170]



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Federal Register / Vol. 73, No. 11 / Wednesday, January 16, 2008 / 
Rules and Regulations

[[Page 2793]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28855; Directorate Identifier 2007-NM-098-AD; 
Amendment 39-15323; AD 2007-26-21]
RIN 2120-AA64


Airworthiness Directives; EMBRAER Model EMB-120, -120ER, -120FC, 
-120QC, and -120RT Airplanes

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

ACTION: Final rule.

-----------------------------------------------------------------------

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:

    Icing tunnel tests on an EMB-120 wing section, conducted under a 
joint Embraer-NASA (National Aeronautics and Space Administration)--
FAA-CTA (Centro T[eacute]cnico Aeroespacial) research program well 
after the EMB-120( ) was type-certificated, have shown that stick 
shaker to stick pusher speed margins may drop below the minimum 
required by the applicable regulations in certain icing conditions. 
Although flight tests have shown that the aircraft handling 
qualities are not adversely affected, these reduced speed margins 
may significantly increase crew workload in certain flight phases.

The unsafe condition is reduced ability of the flightcrew to maintain 
the safe flight and landing of the airplane. We are issuing this AD to 
require actions to correct the unsafe condition on these products.

DATES: This AD becomes effective February 20, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of February 20, 
2008.

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: Dan Rodina, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
227-2125; 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 2, 2007 (72 
FR 42328). That NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states:

    Icing tunnel tests on an EMB-120 wing section, conducted under a 
joint Embraer-NASA (National Aeronautics and Space Administration)--
FAA-CTA (Centro T[eacute]cnico Aeroespacial) research program well 
after the EMB-120( ) was type-certificated, have shown that stick 
shaker to stick pusher speed margins may drop below the minimum 
required by the applicable regulations in certain icing conditions. 
Although flight tests have shown that the aircraft handling 
qualities are not adversely affected, these reduced speed margins 
may significantly increase crew workload in certain flight phases.

The unsafe condition is reduced ability of the flightcrew to maintain 
the safe flight and landing of the airplane. The corrective action 
includes modification of certain electrical wiring and installation of 
a new Stall Warning Computer. 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.

Requests To Change Certain Language

    The Air Line Pilots Association, International (ALPA) asks that the 
unsafe condition specified in paragraph (e) of the NPRM be clarified. 
ALPA states that ``clearly, the accident/incident history of this 
aircraft indicates that handling qualities are adversely affected under 
icing conditions.'' ALPA disagrees with EMBRAER on the statement that 
icing conditions do not adversely affect handling characteristics.
    EMBRAER also asks that the language specified in paragraph (e) of 
the NPRM be clarified. EMBRAER suggests changing the language specified 
in paragraph (e) as follows: ``During icing tunnel research tests 
conducted by the FAA and NASA with the support of CTA (Centro 
T[eacute]cnico Aeroespacial) and EMBRAER in the year 2000, new ice 
shapes were defined for testing on the Model EMB-120 airplane. These 
ice shapes are representative of icing (now defined as intercycle 
icing) that may accumulate in between consecutive boot cycles. Although 
flight testing of these new ice shapes indicated that they do not 
adversely affect the handling characteristics of the Brasilia, the 
testing did indicate that the stick shaker to stick pusher speed 
margins for the intercycle ice shapes may be reduced below the minimum 
standard values set forth in the applicable CTA and FAA Regulations. In 
order to preserve the original certification stick-shaker-to-stick-
pusher margins when operating under the newly defined intercycle icing 
conditions, an upgraded Stall Warning Computer with new settings for 
shaker firing AOA is required to be installed.'' EMBRAER adds that 
during the flight tests no noticeable increase in crew work load was 
experienced.
    We acknowledge the commenter's concerns. However, ALPA's comment 
addresses icing conditions in general; whereas EMBRAER's comment 
addresses stick-shaker-to-stick-pusher speed margins that may drop 
below the minimum required by the applicable regulations in certain 
icing conditions (defined as intercycle icing), which the MCAI 
identifies, in part, as the unsafe condition. Therefore, we have 
clarified the unsafe condition in paragraph (e) by reiterating the 
content of EMBRAER's comment.

[[Page 2794]]

Delay in Issuing AD

    ALPA states that, while a 36-month compliance time appears to be 
reasonable, given the number of aircraft in the U.S. registry, ALPA is 
disappointed that it has taken almost ten years to implement such a 
requirement. ALPA notes that its submission to the National 
Transportation Safety Board following the conclusion of the 1997 
aircraft accident investigation included a proposed safety 
recommendation that was almost identical to the changes being suggested 
in the subject document.
    We understand the commenter's concern regarding a delay in issuing 
this AD. However, the FAA did issue AD 2001-13-14, amendment 39-12295 
(66 FR 34083, June 27, 2001), and AD 2001-20-17, amendment 39-12465 (66 
FR 52027, October 12, 2001). These ADs mitigated the subject unsafe 
condition.

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 change described previously. This change will neither 
increase the economic burden on any operator nor 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.

Costs of Compliance

    We estimate that this AD will affect about 107 products of U.S. 
registry. We also estimate that it will take about 58 work-hours per 
product to comply with the basic requirements of this AD. The average 
labor rate is $80 per work-hour. Required parts will cost up to $2,000 
per product, depending on airplane configuration. Where the service 
information lists required parts costs that are covered under warranty, 
we have assumed that there will be no charge for these costs. As we do 
not control warranty coverage for affected parties, some parties may 
incur costs higher than estimated here. Based on these figures, we 
estimate the cost of the AD on U.S. operators to be up to $710,480, or 
$6,640 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:

2007-26-21 Empresa Brasileira de Aeronautica S.A. (EMBRAER): 
Amendment 39-15323. Docket No. FAA-2007-28855; Directorate 
Identifier 2007-NM-098-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective February 
20, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all EMBRAER Model EMB-120, -120ER, -
120FC, -120QC, and -120RT airplanes; certificated in any category.

Subject

    (d) Air Transport Association (ATA) of America Code 27: Flight 
controls.

Reason

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

    Icing tunnel tests on an EMB-120 wing section, conducted under a 
joint Embraer-NASA (National Aeronautics and Space Administration)--
FAA-CTA (Centro T[eacute]cnico Aeroespacial) research program well 
after the EMB-120( ) was type-certificated, have shown that stick 
shaker to stick pusher speed margins may drop below the minimum 
required by the applicable regulations in certain icing conditions. 
Although flight tests have shown that the aircraft handling 
qualities are not adversely affected, these reduced speed margins 
may significantly increase crew workload in certain flight phases.

During icing tunnel research tests conducted by the FAA and NASA in 
the year 2000, with the support of CTA (Centro T[eacute]cnico 
Aeroespacial) and EMBRAER, new ice shapes were defined for testing 
on the Model EMB-120 airplane. These ice shapes are representative 
of icing (now defined as intercycle icing) that may accumulate in 
between consecutive boot cycles. Although

[[Page 2795]]

flight testing of these new ice shapes indicated that they do not 
adversely affect the handling characteristics of the Brasilia, the 
testing did indicate that the stick-shaker-to-stick-pusher speed 
margins for the intercycle ice shapes may be reduced below the 
minimum standard values set forth in the applicable CTA and FAA 
Regulations. In order to preserve the original certification stick-
shaker-to-stick-pusher margins when operating under the newly 
defined intercycle icing conditions, an upgraded Stall Warning 
Computer with new settings for shaker firing angle-of-attack (AOA) 
is required to be installed. The unsafe condition is reduced ability 
of the flightcrew to maintain the safe flight and landing of the 
airplane. The corrective action includes modification of certain 
electrical wiring and installation of a new Stall Warning Computer.

Actions and Compliance

    (f) Within 36 months after the effective date of this AD, unless 
already done, do the following actions.
    (1) Replace the current Stall Warning Computers with new 
improved ones in accordance with detailed instructions and 
procedures described in the EMBRAER Service Bulletin 120-27-0092, 
Revision 01, dated December 29, 2006.
    (2) Before installing the improved Stall Warning Computers, 
accomplish the detailed instructions and procedures described in the 
EMBRAER Service Bulletin 120-27-0091, Change 02, dated September 29, 
2003.
    (3) As of 36 months after the effective date of this AD, no 
person may install a Stall Warning Computer; part number C-81806-1 
or -2, Mod. A, or C-81806-3, on any airplane.

FAA AD Differences

    Note: This AD differs from the MCAI and/or service information 
as follows: No differences.

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, 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: Dan Rodina, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone (425) 
227-2125; fax (425) 227-1149. Before using any approved AMOC on any 
airplane to which the AMOC applies, notify your appropriate 
principal inspector (PI) in the FAA Flight Standards District Office 
(FSDO), or lacking a PI, your local FSDO.
    (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, the 
Office of Management and Budget (OMB) has approved the information 
collection requirements and has assigned OMB Control Number 2120-
0056.

Related Information

    (h) Refer to MCAI Brazilian Airworthiness Directive 2007-03-03, 
effective April 10, 2007; and EMBRAER Service Bulletins 120-27-0091, 
Change 02, dated September 29, 2003; and 120-27-0092, Revision 01, 
dated December 29, 2006; for related information.

Material Incorporated by Reference

    (i) You must use EMBRAER Service Bulletin 120-27-0091, Change 
02, dated September 29, 2003; or EMBRAER Service Bulletin 120-27-
0092, Revision 01, dated December 29, 2006; as applicable; to do the 
actions required by this AD, unless the AD specifies otherwise. 
EMBRAER Service Bulletin 120-27-0091, Change 02, contains the 
following list of effective pages:

------------------------------------------------------------------------
                               Change level
          Page Nos.            shown on page      Date shown on page
------------------------------------------------------------------------
1, 2, 51, 58................              02  September 29, 2003.
3-50, 52-57, 59-87..........              01  October 15, 2002.
------------------------------------------------------------------------

    (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), P.O. Box 343--CEP 
12.225, Sao Jose dos Campos--SP, Brazil.
    (3) You may review copies at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue SW., Renton, Washington; or 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/cfr/ibr-locations.html.

    Issued in Renton, Washington, on December 21, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-170 Filed 1-15-08; 8:45 am]
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