[Federal Register Volume 66, Number 87 (Friday, May 4, 2001)]
[Proposed Rules]
[Pages 22479-22482]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-11227]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-220-AD]
RIN 2120-AA64


Airworthiness Directives; Fokker Model F.28 Mark 1000, 2000, 
3000, and 4000 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

[[Page 22480]]


ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period.

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SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD), applicable to certain Fokker Model F.28 Mark 1000, 
2000, 3000, and 4000 series airplanes. The proposed AD would have 
required an eddy current inspection to detect cracks in the upper 
girder of the two main landing gear (MLG) brackets; and repair of a 
cracked bracket followed by repetitive inspections, or replacement of a 
cracked MLG bracket with an improved bracket, as applicable. The 
proposed AD also provided for an optional terminating action for 
certain proposed requirements. That proposal was prompted by issuance 
of mandatory continuing airworthiness information by a foreign civil 
airworthiness authority. This new action revises the proposed rule by 
adding new repetitive inspections for certain airplanes, and extending 
the repetitive interval for the repetitive inspections for other 
airplanes. The actions specified by this new proposed AD are intended 
to detect and correct cracks in the upper girder of the MLG bracket, 
which could progress into the vertical stiffeners of the MLG bracket 
and result in reduced structural integrity of the landing gear.

DATES: Comments must be received by May 29, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-220-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. 99-NM-220-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 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, 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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin 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 99-NM-220-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-220-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to add an airworthiness directive (AD), applicable to 
certain Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 series 
airplanes, was published as a notice of proposed rulemaking (NPRM) in 
the Federal Register on November 15, 1999 (64 FR 61796). That NPRM 
would have required an eddy current inspection to detect cracks in the 
upper girder of the two main landing gear (MLG) brackets; and repair of 
a cracked bracket followed by repetitive inspections, or replacement of 
a cracked MLG bracket with an improved bracket, as applicable. That 
NPRM also provided for optional terminating action for certain 
requirements of the proposed AD. That NPRM was prompted by issuance of 
mandatory continuing airworthiness information by a foreign civil 
airworthiness authority. The conditions described in that NPRM, if not 
corrected, could result in cracks in the upper girder of the MLG 
bracket, which could progress into the vertical stiffeners of the MLG 
bracket and result in reduced structural integrity of the landing gear.

Explanation of New Service Information

    Since the issuance of that NPRM, Fokker has issued Service Bulletin 
F28/57-90, Revision 1, dated August 28, 2000. (The NPRM referenced 
Fokker Service Bulletin F28/57-90, dated March 1, 1999, as the 
appropriate source of service information for certain proposed 
actions.) Revision 1 of the service bulletin describes actions similar 
to those in the original issue of the service bulletin, but recommends 
new repetitive inspections for airplanes on which no cracking is 
detected, and increases the repetitive inspection interval from 12 
months to 18 months for airplanes on which cracking is detected. 
Revision 1 of the service bulletin also clarifies the accomplishment 
instructions by providing more detailed instructions for the eddy 
current inspections.
    The Rijksluchtvaartdienst (RLD), which is the airworthiness 
authority for the Netherlands, classified Service Bulletin F28/57-90, 
Revision 1, as mandatory, and issued Dutch airworthiness directive 
1999-045/2, dated October 31, 2000, in order to assure the continued 
airworthiness of these airplanes in the Netherlands.

Comments

    Due consideration has been given to the comments received in 
response to the NPRM. Certain comments have resulted in changes to the 
proposed

[[Page 22481]]

rule, and these comments are addressed below.

Request To Add Repetitive Inspections, Extend Inspection Interval

    One commenter requests that the FAA revise the repetitive 
inspection interval, as proposed in paragraph (a)(2) of the NPRM, to 
correspond with the inspection interval that the airplane manufacturer 
intends to incorporate in the Structural Inspection Program (SIP) 
Document. The interval to which the commenter refers is the 18-month 
repetitive inspection interval for both uncracked and repaired fittings 
of the MLG brackets, as provided in Revision 1 of the service bulletin, 
described previously. As stated above, the FAA has revised the proposal 
in this supplemental NPRM according to the changes in Revision 1 of the 
service bulletin. No further change to the proposal is necessary 
related to this comment.

Request To Correct a Typographical Error

    A commenter points out that, in the ``Differences Between Proposed 
Rule, Foreign Airworthiness Directive, and Service Bulletin'' section 
of the NPRM, the FAA states that replacement of a cracked MLG bracket 
would be required if a crack exceeds 0.0591 inch (15mm) in length. The 
commenter notes that the referenced crack length should be ``0.591.'' 
The FAA acknowledges that this was a typographical error, and has 
ensured that the correct crack length is stated in the parallel section 
of this supplemental NPRM.

Explanation of Change to Cost Impact Information

    In the ``Cost Impact'' section of the NPRM, the FAA stated that the 
proposed AD would affect six airplanes of U.S. registry. Since the 
issuance of the NPRM, two additional airplanes subject to this proposed 
AD have been added to the U.S. Register. The FAA has revised the ``Cost 
Impact'' section of this supplemental NPRM accordingly.

Explanation of New Requirements of Proposal

    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, this new proposed AD would require repetitive 
eddy current inspections to detect cracks in the upper girder of the 
two MLG brackets; and repair of a cracked bracket or replacement of a 
cracked bracket with an improved bracket, as applicable. Such 
replacement would terminate the requirements of this proposed AD. For 
airplanes on which no cracking is detected, replacement of an existing 
bracket with an improved bracket is provided as an optional terminating 
action for the repetitive inspections. The actions would be required to 
be accomplished according to Fokker Service Bulletin F28/57-90, 
Revision 1 (described previously), and Fokker Proforma Service Bulletin 
F28/57-92, dated July 1, 1999 (described in the original NPRM), except 
as noted below. (Operators should note that, although Fokker Proforma 
Service Bulletin F28/57-92 has not been revised since the original 
NPRM, a difference between the proposal and that service bulletin that 
was cited in the original NPRM is restated below for the convenience of 
operators.)

Differences Between Supplemental NPRM, Foreign Airworthiness 
Directive, and Service Bulletins

    This supplemental NPRM differs from Fokker Service Bulletin F28/57-
90, Revision 1, and the parallel Dutch airworthiness directive in that 
it would require, prior to further flight, replacement of a cracked MLG 
bracket with an improved bracket, if a crack exceeds 0.591 inch (15 mm) 
in length. The service bulletin and the Dutch airworthiness directive 
specify replacement of a cracked MLG bracket prior to further flight 
only if a crack exceeds 1.576 inches (40 mm) in length. The FAA has 
determined that, because of the safety implications and consequences 
associated with such cracking, any subject MLG bracket that is found to 
have a crack that exceeds 0.591 (15 mm) in length must be replaced 
prior to further flight.
    Operators should note that Fokker Service Bulletin F28/57-90, 
Revision 1, and the Dutch airworthiness directive specify to replace a 
cracked MLG bracket in accordance with Fokker Proforma Service Bulletin 
F28/57-92, or to contact the manufacturer for replacement instructions. 
However, this supplemental NPRM would require replacement of a cracked 
MLG bracket to be accomplished in accordance with Fokker Proforma 
Service Bulletin F28/57-92.
    Operators also should note that, although Fokker Proforma Service 
Bulletin F28/57-92, including any appendix referenced in that proforma 
service bulletin, may specify that the manufacturer may be contacted if 
any discrepancies are found during the replacement of the MLG bracket, 
this proposal would require correction of the discrepancies in 
accordance with a method approved by the FAA, or the RLD (or its 
delegated agent). In light of the type of corrective action that would 
be required to address the identified unsafe condition, and in 
consonance with existing bilateral airworthiness agreements, the FAA 
has determined that, for this supplemental NPRM, corrective action 
approved by either the FAA or the RLD would be acceptable for 
compliance with this proposed AD.

Conclusion

    Since the changes described above expand the scope of the 
originally proposed rule, the FAA has determined that it is necessary 
to reopen the comment period to provide additional opportunity for 
public comment.

Cost Impact

    The FAA estimates that 8 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 inspection, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$960, or $120 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 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); 
and (3) if promulgated, will not have a significant economic impact, 
positive or negative, on a substantial number of small entities

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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-220-AD.

    Applicability: Model F.28 Mark 1000, 2000, 3000, and 4000 series 
airplanes; serial numbers 11003 through 11091 inclusive, 11094 
through 11171 inclusive, 11991, and 11992; 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 (f) 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 detect and correct cracks in the upper girder of the main 
landing gear (MLG) bracket, which could progress into the vertical 
stiffeners of the MLG bracket and result in reduced structural 
integrity of the landing gear, accomplish the following:

Repetitive Inspections and Corrective Actions

    (a) Within 12 months after the effective date of this AD, 
perform an eddy current inspection of the upper girder of the MLG 
brackets on the left and right sides of the airplane for cracks, in 
accordance with the Accomplishment Instructions of Fokker Service 
Bulletin F28/57-90, Revision 1, dated August 28, 2000.
    (1) If no cracks are found, repeat the inspection at least every 
18 months, until accomplishment of paragraph (d) of this AD.
    (2) Except as provided by paragraph (c) of this AD, if any crack 
is found, prior to further flight, repair as specified in paragraph 
C.(1) of the Accomplishment Instructions of the service bulletin, in 
accordance with the service bulletin. Thereafter, repeat the eddy 
current inspection at intervals not to exceed 18 months, until 
accomplishment of paragraph (d) of this AD.

    Note 2: Inspections accomplished before the effective date of 
this AD in accordance with Fokker Service Bulletin F28/57-90, dated 
March 1, 1999, are considered acceptable for compliance with 
paragraph (a) of this AD.

Reporting Requirement

    (b) Within 10 days after accomplishing each inspection required 
by paragraph (a) of this AD, submit a report of the inspection 
results to: Fokker Services B.V., Technical Services, 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.

Replacement

    (c) For airplanes on which a crack greater than 0.591 inch (15 
mm) in length is found: Except as provided by paragraph (e) of this 
AD, prior to further flight, replace the cracked MLG bracket with a 
new, improved bracket (including measuring the position of the 
existing MLG bracket, removing the existing bracket and attachment 
fittings, checking alignment of the fastener holes, measuring gaps, 
installing a shim, and aligning the new bracket); in accordance with 
Fokker Proforma Service Bulletin F28/57-92, dated July 1, 1999. Such 
replacement constitutes terminating action for the repetitive 
inspections required by paragraph (a) of this AD.

Optional Terminating Action

    (d) Except as provided by paragraph (e) of this AD, replacement 
of the MLG bracket with a new, improved bracket (including measuring 
the position of the existing MLG bracket, removing the existing 
bracket and attachment fittings, checking alignment of the fastener 
holes, measuring gaps, installing a shim, and aligning the new 
bracket), in accordance with Fokker Proforma Service Bulletin F28/
57-92, dated July 1, 1999; constitutes terminating action for the 
repetitive inspections specified in paragraph (a) of this AD for the 
replaced bracket.
    (e) If any discrepancy is detected during accomplishment of the 
replacement procedures, and the service bulletin or any appendix to 
the service bulletin specifies to contact Fokker for appropriate 
action: Prior to further flight, repair in accordance with a method 
approved by either the Manager, International Branch, ANM-116, FAA, 
Transport Airplane Directorate; or the Rijksluchtvaartdienst (or its 
delegated agent).

Alternative Methods of Compliance

    (f) 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

    (g) 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 1999-045/2, dated October 31, 2000.


    Issued in Renton, Washington, on April 30, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-11227 Filed 5-3-01; 8:45 am]
BILLING CODE 4910-13-U