[Federal Register Volume 66, Number 214 (Monday, November 5, 2001)]
[Proposed Rules]
[Pages 55896-55898]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-27666]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-128-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) this is applicable to certain Fokker Model F.28 Mark 
0070 and 0100 series airplanes. This proposal would require repetitive 
operational tests for discrepancies of the heating system of pitot tube 
#1, and replacement of the pilot tube, if necessary. This proposal also 
would require eventual modification of the alternating current sensing 
circuit for pitot tube #1, which would terminate the repetitive 
operational test requirement. This action is necessary to prevent 
failure of the heating system of pitot tube #1 due to a short circuit, 
which may go undetected and lead to the pilot receiving erroneous 
airspeed indications, resulting in reduced control of the airplane. The 
action is intended to address the identified unsafe condition.

DATES: Comments must be received by December 5, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-128-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 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. 2001-NM-128-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 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Fokker Services, V.V., P.O. Box 231, 2150 AE Nieuw-
Vennep, the Netherlands. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Tom Rodriguez, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-1137; 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 issues-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin specific 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 2001-NM-128-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. 2001-NM-128-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports that the captain's airspeed indicator 
failed during flight in icing conditions on certain Fokker Model F.28 
Mark 0070 and 0100 series airplanes. Another report advises that an 
operator reported snow on the pitot tube while the pitot tube's heating 
element was switched on. Investigation has revealed that these 
conditions are caused by a short circuit in the pitot tube's heating 
element, which can remain undetected because of the placement of the 
alternating current (AC) sensing circuit for pitot tube #1. Undetected 
failure of the pitot tube heating system can lead to pitot tube #1 
being blocked by ice. This condition, if not corrected, could lead to 
the pilot receiving erroneous airspeed indications, resulting in 
reduced control of the airplane.

Explanation of Relevant Service Information

    Fokker Services B.V. has issued Fokker Service Bulletin SBF100-30-
025, Revision 1, dated March 14, 2001, which describes procedures for 
repetitive operational tests for discrepancies of the heating system of 
pitot tube #1, and replacement of the pitot tube, if necessary. The 
operational tests are intended to ensure that the heaters of the pitot 
tube and mast are functioning. The service bulletin also describes 
procedures for modification of the AC sensing circuit for pitot tube 
#1. The modification involves removing the supply current wire from the 
AC current sensor for the pitot tube, removing the wire that grounds 
the heating system of pitot tube #1, installing the supply current wire 
to the inverter, installing the return current wire from from pitot 
tube #1 to the AC current sensor, and grounding the AC current sensor. 
Accomplishment of this modification will ensure that the flight crew 
will be able to detect a short circuit in the heating system of pitot 
tube #1, should such a short circuit occur. Therefore, such 
modification eliminates the need for the repetitive operational tests. 
Accomplishment of the actions specified in the service bulletin is 
intended to adequately address the identified unsafe condition.

[[Page 55897]]

U.S. Type Certification of the Airplane

    This aiplane model is manufactured in the Netherlands and is 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.

Explanation of Requirements of Proposed Rule

    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 require accomplishment of 
the actions specified in the service bulletin described previously. The 
proposed AD also would require that operators report results of 
inspection findings to the airplane manufacturer.

Cost Impact

    The FAA estimates that 129 airplanes of U.S registry would be 
affected by this proposed AD.
    It would take approximately 1 work hour per airplane to accomplish 
the proposed operational test, at the average labor rate of $60 per 
work hour. Based on these figures, the cost impact of the proposed AD 
on U.S. operators is estimated to be $7,740, or $60 per airplane, per 
test cycle.
    It would take approximately 34 work hours per airplane to 
accomplish the proposed modification, at the average labor rate of $60 
per work hour. Required parts would cost approximately $350 per 
airplane. Based on these figures, the cost impact of the proposed AD on 
U.S. operators is estimated to be $308,310, or $2,390 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the proposed requirements 
of this AD action, and that no operator would accomplish those actions 
in the future if this proposed 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); an 
(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 adding the following new 
airworthiness directive.

Fokker Services B.V.: Docket 2001-NM-128-AD.

    Applicability: Model F.28 Mark 0070 and 0100 series airplanes, 
serial numbers 11244 through 11585 inclusive, on which Fokker 
Service Bulletin SBF100-30-019 or SBF100-30-020 has been 
accomplished, certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (e) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of the heating system of pitot tube #1 due to 
a short circuit, which may go undetected and lead to the pilot 
receiving erroneous airspeed indications, resulting in reduced 
control of the airplane, accomplish the following:

Operational Test

    (a) Within 3 months after the effective date of this AD, do an 
operational test for discrepancies (i.e., correct functioning) of 
the heating system of pitot tube #1, according to Fokker Service 
Bulletin SFB100-30-025, Revision 1, dated March 14, 2001. Repeat the 
operational test every 12 months, until paragraph (d) of this AD has 
been done.

Replacement of Pitot Tube

    (b) If any discrepancy is found during the operational test 
required by paragraph (a) of this AD: Before further flight, replace 
pitot tube #1 with a new pitot tube, according to Fokker Service 
Bulletin SBF100-30-025, Revision 1, dated March 14, 2001.

Reporting Requirement

    (c) At the applicable time specified in paragraph (c)(1) or 
(c)(2) of this AD: Use page 38 of Fokker Service Bulletin SBF100-30-
025, Revision 1, dated March 14, 2001, to submit a report of 
findings from each operational test (both positive and negative) to 
Fokker Services B.V., Attn: Manager Airline Support, P.O. Box 231, 
2150 AE Nieuw-Vennep, the Netherlands. Information collection 
requirements contained in this regulation have been approved by the 
Office of Management and Budget (OMB) under the provisions of the 
Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have 
been assigned OMB Control Number 2120-0056.
    (1) For airplanes on which the operational test is accomplished 
after the effective date of this AD: Submit the report within 5 days 
after performing the test required by paragraph (a) of this AD.
    (2) For airplanes on which the operational test is accomplished 
before the effective date of this AD: Submit the report within 5 
days after the effective date of this AD.

Modification

    (d) Within 36 months after the effective date of this AD, modify 
the alternating current (AC) sensing circuit for pitot tube #1 
(including removing the supply current wire from the AC current 
sensor for the pitot tube, removing the wire that grounds the 
heating system of pitot tube #1, installing the supply current wire 
to the inverter, installing the return current wire from pitot tube 
#1 to the AC current sensor, and grounding the AC current sensor), 
according to Fokker Service Bulletin SBF100-30-025, Revision 1, 
dated March 14, 2001. Such modification terminates the repetitive 
operational tests required by paragraph (a) of this AD.

Alternative Methods of Compliance

    (e) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager,

[[Page 55898]]

International Branch, ANM-116, Transport Airplane Directorate, FAA. 
Operators shall submit their requests through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, International Branch, ANM-116.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

Special Flight Permits

    (f) 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 requirements of this AD can be accomplished.

    Dated: Issued in Renton, Washington, on October 30, 2001.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-27666 Filed 11-2-01; 8:45 am]
BILLING CODE 4910-13-M