Document ID: FAA-2008-0231-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Fokker F.28 Mark 0070 and Mark 0100 Airplanes
Posted Date: 2008-03-03T05:00Z

[Federal Register: March 3, 2008 (Volume 73, Number 42)]
[Proposed Rules]               
[Page 11366-11369]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr03mr08-17]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0231; Directorate Identifier 2007-NM-218-AD]
RIN 2120-AA64

 
Airworthiness Directives; Fokker F.28 Mark 0070 and Mark 0100 
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
products listed above. This proposed 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:

    To date, there have been at least 10 reported events on Fokker 
70 (F28 Mark 0070) and Fokker 100 (F28 Mark 0100) aircraft where the 
flight crew manually overpowered the autopilot, inadvertently 
neglecting to disengage the autopilot. * * * When the autopilot is 
not disengaged, the elevator servomotor is overpowered and the 
horizontal stabilizer is moved by the Automatic Flight Control & 
Augmentation System (AFCAS) auto-trim in a direction opposite to the 
(manual) deflection of the elevator, causing high elevator control 
forces. This condition, if not corrected, could cause the stabilizer 
to move to an extreme out-of-trim position, creating the (remote) 
possibility of loss of control of the aircraft, due to the extreme 
control loads.

    The proposed AD would require actions that are intended to address 
the unsafe condition described in the MCAI.

DATES: We must receive comments on this proposed AD by April 2, 2008.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-40, 1200 New 
Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.

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 this proposed AD, 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.

FOR FURTHER INFORMATION CONTACT: Tom Rodriguez, Aerospace Engineer,

[[Page 11367]]

International Branch, ANM-116, Transport Airplane Directorate, FAA, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
227-1137; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2008-0231; 
Directorate Identifier 2007-NM-218-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD based on those comments.
    We will post all comments we receive, without change, to http://
www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    The Civil Aviation Authority--The Netherlands (CAA-NL), which is 
the aviation authority for the Netherlands, has issued Dutch 
Airworthiness Directive NL-2006-010, dated July 14, 2006 (referred to 
after this as ``the MCAI''), to correct an unsafe condition for the 
specified products. The MCAI states:

    To date, there have been at least 10 reported events on Fokker 
70 (F28 Mark 0070) and Fokker 100 (F28 Mark 0100) aircraft where the 
flight crew manually overpowered the autopilot, inadvertently 
neglecting to disengage the autopilot. Detailed investigation of 
these incidents has shown that this usually occurs in a high 
workload environment that demands immediate manual control of the 
aircraft by the pilot flying, e.g., terrain warning. When the 
autopilot is not disengaged, the elevator servomotor is overpowered 
and the horizontal stabilizer is moved by the Automatic Flight 
Control & Augmentation System (AFCAS) auto-trim in a direction 
opposite to the (manual) deflection of the elevator, causing high 
elevator control forces. This condition, if not corrected, could 
cause the stabilizer to move to an extreme out-of-trim position, 
creating the (remote) possibility of loss of control of the 
aircraft, due to the extreme control loads. In the original design 
of AFCAS, operation of the control wheel-mounted stabilizer trim 
switches has no effect when the autopilot is engaged. Based on the 
assumption that stabilizer trim switches will be operated by the 
pilot flying when encountering high control forces, an Autopilot 
Disconnect Unit has been developed that disconnects the autopilot 
when the stabilizer trim switches are operated. Since a potentially 
unsafe condition has been identified that may exist or develop on 
aircraft of this type design, this Airworthiness Directive requires 
the installation of Autopilot Disconnect Units and associated wiring 
changes.

    You may obtain further information by examining the MCAI in the AD 
docket.

Relevant Service Information

    Fokker Services B.V. has issued Fokker Service Bulletin SBF100-22-
050, dated April 25, 2006, including the drawings listed in the 
following table. The actions described in this service information are 
intended to correct the unsafe condition identified in the MCAI.

                           Drawings Included in Fokker Service Bulletin SBF100-27-050
----------------------------------------------------------------------------------------------------------------
            Fokker drawing                Sheet              Issue                           Date
----------------------------------------------------------------------------------------------------------------
W41501................................        057  CQ.......................  April 25, 2006.
W41501................................        058  CQ.......................  April 25, 2006.
W41501................................        059  CQ.......................  April 25, 2006.
W41501................................        060  CQ.......................  April 25, 2006.
W41501................................        061  CR.......................  April 25, 2006.
W41501................................        062  CR.......................  April 25, 2006.
W41504................................        009  K........................  April 25, 2006.
W41504................................        010  K........................  April 25, 2006.
W41504................................        011  J........................  April 25, 2006.
W41504................................        012  L........................  April 25, 2006.
W41504................................        013  L........................  April 25, 2006.
W46140................................         27  AR.......................  March 5, 2002.
W46140................................         28  AR.......................  March 8, 2002.
W46143................................         02  K........................  February 26, 2002.
W46143................................         03  K........................  March 8, 2002.
W46144................................         06  R........................  March 4, 2002.
W46144................................         07  S........................  March 7, 2002.
W46912................................         01  D........................  March 12, 2002.
W46930................................         01  Original.................  March 14, 2002.
W46930................................         02  E........................  March 14, 2002.
W46932................................         01  D........................  March 13, 2002.
W59140................................        177  GC.......................  February 8, 2006.
W59140................................        178  GB.......................  February 6, 2006.
W59140................................        221  GB.......................  February 6, 2006.
----------------------------------------------------------------------------------------------------------------

FAA's Determination and Requirements of This Proposed AD

    This product has been approved by the aviation authority of another 
country, and is approved for operation in the United States. Pursuant 
to our bilateral agreement with the State of Design Authority, we have 
been notified of the unsafe condition described in the MCAI and service 
information referenced above. We are proposing this AD because we 
evaluated all pertinent information and determined an unsafe condition 
exists and is likely to exist or develop on other products of the same 
type design.

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

[[Page 11368]]

substantively from the information provided in the MCAI and related 
service information.
    We might also have proposed different actions in this AD from those 
in the MCAI in order to follow FAA policies. Any such differences are 
highlighted in a NOTE within the proposed AD.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about 12 products of U.S. registry. We also estimate that 
it would take about 27 work-hours per product to comply with the basic 
requirements of this proposed AD. The average labor rate is $80 per 
work-hour. Required parts would cost about $3,000 per product. 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 proposed AD on U.S. operators to 
be $61,920, or $5,160 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 proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify 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. 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 proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The FAA amends Sec.  39.13 by adding the following new AD:

Fokker Services B.V.: Docket No. FAA-2008-0231; Directorate 
Identifier 2007-NM-218-AD.

Comments Due Date

    (a) We must receive comments by April 2, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Fokker Model F.28 Mark 0070 and 0100 
airplanes, all serial numbers; certificated in any category.

Subject

    (d) Air Transport Association (ATA) of America Code 22: Auto 
flight.

Reason

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

    To date, there have been at least 10 reported events on Fokker 
70 (F28 Mark 0070) and Fokker 100 (F28 Mark 0100) aircraft where the 
flight crew manually overpowered the autopilot, inadvertently 
neglecting to disengage the autopilot. Detailed investigation of 
these incidents has shown that this usually occurs in a high 
workload environment that demands immediate manual control of the 
aircraft by the pilot flying, e.g. terrain warning. When the 
autopilot is not disengaged, the elevator servomotor is overpowered 
and the horizontal stabilizer is moved by the Automatic Flight 
Control & Augmentation System (AFCAS) auto-trim in a direction 
opposite to the (manual) deflection of the elevator, causing high 
elevator control forces. This condition, if not corrected, could 
cause the stabilizer to move to an extreme out-of-trim position, 
creating the (remote) possibility of loss of control of the 
aircraft, due to the extreme control loads. In the original design 
of AFCAS, operation of the control wheel-mounted stabilizer trim 
switches has no effect when the autopilot is engaged. Based on the 
assumption that stabilizer trim switches will be operated by the 
pilot flying when encountering high control forces, an Autopilot 
Disconnect Unit has been developed that disconnects the autopilot 
when the stabilizer trim switches are operated. Since a potentially 
unsafe condition has been identified that may exist or develop on 
aircraft of this type design, this Airworthiness Directive requires 
the installation of Autopilot Disconnect Units and associated wiring 
changes.

Actions and Compliance

    (f) Within 36 months after the effective date of this AD, unless 
already done, install autopilot disconnect units and do associated 
wiring changes in accordance with Section 3, ``Accomplishment 
Instructions,'' of Fokker Service Bulletin SBF100-22-050, dated 
April 25, 2006, including the drawings listed in Table 1 of this AD.

                      Table 1.--Drawings Included in Fokker Service Bulletin SBF100-27-050
----------------------------------------------------------------------------------------------------------------
            Fokker drawing                Sheet              Issue                           Date
----------------------------------------------------------------------------------------------------------------
W41501................................        057  CQ.......................  April 25, 2006.
W41501................................        058  CQ.......................  April 25, 2006.
W41501................................        059  CQ.......................  April 25, 2006.
W41501................................        060  CQ.......................  April 25, 2006.
W41501................................        061  CR.......................  April 25, 2006.
W41501................................        062  CR.......................  April 25, 2006.
W41504................................        009  K........................  April 25, 2006.
W41504................................        010  K........................  April 25, 2006.

[[Page 11369]]

W41504................................        011  J........................  April 25, 2006.
W41504................................        012  L........................  April 25, 2006.
W41504................................        013  L........................  April 25, 2006.
W46140................................         27  AR.......................  March 5, 2002.
W46140................................         28  AR.......................  March 8, 2002.
W46143................................         02  K........................  February 26, 2002.
W46143................................         03  K........................  March 8, 2002.
W46144................................         06  R........................  March 4, 2002.
W46144................................         07  S........................  March 7, 2002.
W46912................................         01  D........................  March 12, 2002.
W46930................................         01  Original.................  March 14, 2002.
W46930................................         02  E........................  March 14, 2002.
W46932................................         01  D........................  March 13, 2002.
W59140................................        177  GC.......................  February 8, 2006.
W59140................................        178  GB.......................  February 6, 2006.
W59140................................        221  GB.......................  February 6, 2006.
----------------------------------------------------------------------------------------------------------------

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, 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: Tom 
Rodriguez, Aerospace Engineer, International Branch, ANM-116, FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; telephone (425) 227-1137; 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 Dutch Airworthiness Directive NL-2006-010, 
dated July 14, 2006; and Fokker Service Bulletin SBF100-22-050, 
dated April 25, 2006, including the drawings listed in Table 1 of 
this AD; for related information.

    Issued in Renton, Washington, on February 25, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-3971 Filed 2-29-08; 8:45 am]

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