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[Federal Register Volume 65, Number 24 (Friday, February 4, 2000)]
[Proposed Rules]
[Pages 5456-5458]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-2470]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-369-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

[[Page 5457]]

directive (AD) that is applicable to all Fokker Model F.28 Mark 0070 
and 0100 series airplanes. This proposal would require installation of 
new, improved bonding jumpers on the horizontal stabilizer. This 
proposal is prompted by issuance of mandatory continuing airworthiness 
information by a foreign civil airworthiness authority. The actions 
specified by the proposed AD are intended to ensure adequate electrical 
bonding between the horizontal and vertical stabilizers. Inadequate 
electrical bonding, in the event of a lightning strike, could cause 
electrical arcing, and result in damage to the hydraulic lines and 
consequent failure of the hydraulic systems.

DATES:  Comments must be received by March 6, 2000.

ADDRESSES:  Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-369-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.
    The service information referenced in the proposed rule may be 
obtained from Fokker Services B.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:  Norman B. Martenson, Manager, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2110; 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 notice may be changed in light of 
the comments received.
    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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NM-369-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. 99-NM-369-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Rijksluchtvaartdienst (RLD), which is the airworthiness 
authority for the Netherlands, notified the FAA that an unsafe 
condition may exist on all Fokker Model F.28 Mark 0070 and 0100 series 
airplanes. The RLD advises that in February 1988, during a routine 
scheduled flight, a Fokker Model F.28 Mark 0100 series airplane was 
struck by lightning. The report indicated that the No. 2 hydraulic 
system's ``Low Quantity Warning'' occurred; shortly thereafter, the 
same warning occurred on the No. 1 hydraulic system. Although only the 
hydraulic accumulator-driven systems remained available after the 
``Total Hydraulic Failure'' procedure was accomplished, the flight crew 
was able to land the airplane safely. Investigation revealed that the 
lightning current penetrated the vertical stabilizer and bonding jumper 
of the horizontal stabilizer.

Bonding Jumper Design

    At present, on Fokker Model F.28 Mark 0070 and 0100 series 
airplanes, only a single bonding jumper is installed between the 
vertical and horizontal stabilizer on the left-hand side. (Currently, 
no bonding jumper is installed on the right-hand side.) Reports 
indicate that a bonding jumper had melted, although it is unclear 
whether this was due to the lightning strike event preceding the 
hydraulic systems failure, or due to an earlier event. In either case, 
because the bonding jumper failed, the electrical arcing that resulted 
from the lightning strike damaged the hydraulic lines.
    Further investigation revealed that the existing bonding jumper 
installation is not adequate to meet certain requirements, and the RLD 
advises that it is necessary to improve the electrical bonding of the 
horizontal stabilizer. Inadequate electrical bonding between the 
horizontal and vertical stabilizers, in the event of a lightning 
strike, could cause electrical arcing, and result in damage to the 
hydraulic lines and consequent failure of the hydraulic systems.

Explanation of Relevant Service Information

    Fokker has issued Service Bulletin SBF100-23-032, dated September 
22, 1999, which describes procedures for installing new, improved 
bonding jumpers on the horizontal stabilizer. On the left-hand side of 
the horizontal stabilizer, installation procedures include removing the 
existing bonding jumper of the horizontal stabilizer torsion box and 
replacing it with a new, improved bonding jumper; removing and 
discarding the existing fasteners; and ensuring that the fastener holes 
are in proper condition. On the right-hand side of the horizontal 
stabilizer, installation procedures include drilling new fastener holes 
in the horizontal stabilizer hinge fitting and in the lower skin of the 
horizontal stabilizer torsion box; deburring all drilled holes; and 
installing a new, improved bonding jumper. The Fokker service bulletin 
references Fokker 70/100 Aircraft Maintenance Manual (AMM), Chapter 20-
13-05, as an additional source of service information to accomplish the 
installation of the new bonding jumpers.
    Accomplishment of the actions specified in the service bulletin is 
intended to adequately address the identified unsafe condition. The RLD 
classified this service bulletin as mandatory and issued Dutch 
airworthiness directive 1999-128(A), dated October 29, 1999, in order 
to assure the continued airworthiness of these airplanes in the 
Netherlands.

FAA's Conclusions

    This airplane 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. Pursuant to this 
bilateral airworthiness agreement, the RLD has kept the FAA informed of 
the situation described above. The FAA has examined the findings of the 
RLD, reviewed all available information, and determined that AD action 
is necessary

[[Page 5458]]

for products of this type design that are certificated for operation in 
the United States.

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 the accomplishment 
of the actions specified in accordance with the service bulletin 
described previously, except as discussed below.

Differences Between Proposed Rule and Service Bulletin

    Operators should note that, although the service bulletin 
recommends a compliance time of 24 months for accomplishment of the 
actions specified in the service bulletin, the RLD has mandated a 
compliance time of 18 months. The FAA concurs with the RLD and has 
determined that an 18-month compliance time would have a limited impact 
on the operators while ensuring the continued safety of the fleet. In 
determining the proposed compliance time, the FAA considered the safety 
implications, average utilization rate of the affected fleet, and 
availability of required modification parts. In light of this, the FAA 
considers that the proposed compliance time of 18 months is 
appropriate.

Cost Impact

    The FAA estimates that 129 Fokker Model F.28 Mark 0070 and 0100 
series airplanes of U.S. registry would be affected by this proposed 
AD, that it would take approximately 2 work hours per airplane to 
accomplish the proposed actions, and that the average labor rate is $60 
per work hour. Required parts would cost approximately $69 per 
airplane. Based on these figures, the cost impact of the proposed AD on 
U.S. operators is estimated to be $24,381, or $189 per airplane.
    The cost impact figure discussed above is 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 AD were not adopted.

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 adding the following new 
airworthiness directive:

Fokker Services B.V.: Docket 99-NM-369-AD.

    Applicability: All Model F.28 Mark 0070 and 0100 series 
airplanes, certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
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 (b) 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 ensure adequate electrical bonding between the horizontal and 
vertical stabilizers, accomplish the following:
    (a) Within 18 months after the effective date of this AD, 
accomplish the actions required by paragraphs (a)(1) and (a)(2) of 
this AD, in accordance with the Accomplishment Instructions of 
Fokker Service Bulletin SBF100-23-032, dated September 22, 1999.
    (1) On the left-hand side of the horizontal stabilizer, replace 
the existing bonding jumper on the horizontal stabilizer torsion box 
with a new, improved bonding jumper.
    (2) On the right-hand side of the horizontal stabilizer, install 
a new, improved bonding jumper.

    Note 2: Fokker Service Bulletin SBF100-23-032, dated September 
22, 1999, references Fokker 70/100 Aircraft Maintenance Manual 
(AMM), Chapter 20-13-05, as an additional source of service 
information to accomplish the installation of the new bonding 
jumpers.

Alternative Methods of Compliance

    (b) 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, International Branch, ANM-116, FAA, 
Transport Airplane Directorate. 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 3: 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

    (c) 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.

    Note 4: The subject of this AD is addressed in Dutch 
airworthiness directive 1999-128(A), dated October 29, 1999.

    Issued in Renton, Washington, on January 31, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-2470 Filed 2-3-00; 8:45 am]
BILLING CODE 4910-13-P
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