[Federal Register Volume 60, Number 243 (Tuesday, December 19, 1995)]
[Proposed Rules]
[Pages 65256-65258]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-30746]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-172-AD]
Airworthiness Directives; Fokker Model F28 Mark 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) that is applicable to certain Fokker Model F28 Mark 0100
series airplanes. This proposal would require a one-time measurement
during refueling to determine the pressure in each collector tank; for
certain airplanes, non-destructive test (NDT) inspections to detect
cracking or deformations of the collector tank ribs on each wing, and
repair, if necessary; and modification of top-hat stringers in each
outer wing tank. This proposal is prompted by a report of damage to the
ribs of the wing collector tank caused by over-pressure in the
collector tank during refueling. The actions specified by the proposed
AD are intended to prevent cracking and deformation of the wing
collector tanks due to over-pressure, which could result in reduced
structural integrity of the wing.
DATES: Comments must be received by January 30, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-172-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 Aircraft USA, Inc., 1199 North Fairfax Street,
Alexandria, Virginia 22314. This information may be examined at the
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington.
FOR FURTHER INFORMATION CONTACT: Ruth E. Harder, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
[[Page 65257]]
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-1721; fax (206) 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 95-NM-172-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-103, Attention: Rules
Docket No. 95-NM-172-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Rijksluchtvaartdienst (RLD), which is the airworthiness
authority for the Netherlands, recently notified the FAA that an unsafe
condition may exist on certain Fokker Model F28 Mark 0100 series
airplanes. The RLD advises, that during scheduled maintenance on a
Model F28 Mark 0100 series airplane, the ribs in the right-hand wing
collector tank were found to be damaged. Investigation revealed that
the damage was caused by over-pressure in the collector tank during
refueling.
The top-hat stringers between the wing collector tank and the outer
wing tank contain restriction blocks that are intended to close off,
but still ventilate the collector tank. The four forward most top-hat
stringers (2.32, 2.33, 2.34, and 2.35) should not contain these
restriction blocks, which would enable fuel to flow from the wing
collector tank to the outer wing tank. Subsequent investigation
revealed that the over-pressure was due to the installation of
restriction blocks in these four top-hat stringers, which adversely
affected the fuel transfer capacity of these airplanes. This condition,
if not corrected, could result in cracking and deformation of the ribs
in the wing collector tank, which could lead to reduced structural
integrity of the wing.
Fokker has issued Service Bulletin SBF 100-57-030, dated December
17, 1994, which describes procedures for conducting a one-time
measurement during refueling to determine the pressure in each
collector tank. The service bulletin also describes procedures for
conducting non-destructive test (NDT) inspections of certain airplanes
to detect cracking and deformations of the collector tank ribs at wing
stations 1825, 2230, and 2635.
Fokker has also issued Service Bulletin SBF 100-57-029, Revision 1,
dated March 23, 1995, which describes procedures for modification of
the four top-hat stringers (2.32, 2.33, 2.34, and 2.35) in the outer
wing tank area. This modification entails removal of the restriction
blocks in the top-hat stringers.
The RLD classified both of these service bulletins as mandatory and
issued the Netherlands airworthiness directive BLA 1994-172 (A), dated
December 23, 1994, in order to assure the continued airworthiness of
these airplanes in the Netherlands.
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 for products of this type design that are certificated for
operation in the United States.
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design, the
proposed AD would require a one-time measurement during refueling to
determine the pressure in each collector tank; and modification of the
four top-hat stringers in the outboard wing tank area. For certain
airplanes, this proposed AD would require non-destructive test (NDT)
inspections of the collector tank ribs to detect cracking or
deformations. The actions would be required to be accomplished in
accordance with the service bulletins described previously.
This AD also proposes to require repair of any cracking or
deformations in accordance with a method approved by the FAA.
The FAA estimates that 58 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 85 work
hours per airplane to accomplish the proposed actions, 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
$295,800, or $5,100 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.
The regulations proposed herein would not have substantial direct
effects 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, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
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
[[Page 65258]]
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), 40101, 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Fokker: Docket 95-NM-172-AD.
Applicability: Model F28 Mark 0100 airplanes, serial numbers
11244 through 11277 inclusive, 11279, 11281 through 11287 inclusive,
and 11289 through 11400 inclusive, 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 use the authority
provided in paragraph (g) of this AD to request approval from the
FAA. This approval may address either no action, if the current
configuration eliminates the unsafe condition; or different actions
necessary to address the unsafe condition described in this AD. Such
a request should include an assessment of the effect of the changed
configuration on the unsafe condition addressed by this AD. In no
case does the presence of any modification, alteration, or repair
remove any airplane from the applicability of this AD.
Compliance: Required as indicated, unless accomplished
previously.
To prevent over-pressurization and/or damage to the wing
collector tanks, which could result in reduced structural integrity
of the wings, accomplish the following:
(a) Within 45 days after the effective date of this AD, perform
a one-time measurement during refueling to determine the pressure in
each collector tank in accordance with Part 1 of the Accomplishment
Instructions of Fokker Service Bulletin SBF100-57-030, dated
December 17, 1994.
Note 2: Pressure Limits Categories are defined in Table 2 of
Fokker Service Bulletin SBF100-57-030, dated December 17, 1994.
(b) For Pressure Limits Category 1: Within 2 years after the
effective date of this AD, modify the four affected top-hat
stringers (2.32, 2.33, 2.34, and 2.35) in each outer wing tank area
by removing the restriction blocks, in accordance with the
Accomplishment Instructions of Fokker Service Bulletin SBF100-57-
029, Revision 1, dated March 23, 1995.
(c) For Pressure Limits Categories 2 through 5: Except as
provided by paragraph (d) of this AD, prior to the number of
accumulated total flight cycles or within the time specified in
Table 1 of Fokker Service Bulletin SBF100-57-030, dated December 17,
1994, whichever occurs earlier, accomplish the requirements of
paragraphs (c)(1) and (c)(2) of this AD.
(1) Perform the Non-Destructive Test (NDT) inspections specified
in Part 2 of the Accomplishment Instructions of Fokker Service
Bulletin SBF100-57-030, dated December 17, 1994, to detect cracking
or deformations of the collector tank ribs on each wing at wing
stations 1825, 2230, and 2635. These inspections are to be performed
in accordance with Fokker Service Bulletin SBF100-57-030, dated
December 17, 1994.
(2) Modify the four affected top-hat stringers (2.32, 2.33,
2.34, and 2.35) in each outer wing tank area by removing the
restriction blocks, in accordance with the Accomplishment
Instructions of Fokker Service Bulletin SBF100-57-029, Revision 1,
dated March 23, 1995.
(d) For Pressure Limits Category 6, and for airplanes having
pressure limits within the limits specified in Categories 3 through
5 and that have exceeded the number of accumulated total flight
cycles specified in Table 1: Within 100 flight cycles, accomplish
the requirements of paragraphs (d)(1) and (d)(2) of this AD.
(1) Perform the NDT inspections in accordance with the
procedures of Part 2 of the Accomplishment Instructions of Fokker
Service Bulletin SBF100-57-030, dated December 17, 1994. The fueling
pressure must not exceed 25 pounds per square inch (PSI) during
refueling.
(2) Modify the four affected top-hat stringers (2.32, 2.33,
2.34, and 2.35) in each outer wing tank area by removing the
restriction blocks, in accordance with the Accomplishment
Instructions of Fokker Service Bulletin SBF100-57-029, Revision 1,
dated March 23, 1995.
(e) For Pressure Limits Category 7: Prior to further flight
following the measurement required by paragraph (a) of this AD,
accomplish the requirements of paragraphs (e)(1) and (e)(2) of this
AD.
(1) Perform the NDT inspections in accordance with the
procedures of Part 2 of the Accomplishment Instructions of Fokker
Service Bulletin SBF100-57-030, dated December 17, 1994.
(2) Modify the four affected top-hat stringers (2.32, 2.33,
2.34, and 2.35) in each outer wing tank area by removing the
restriction blocks, in accordance with the Accomplishment
Instructions of Fokker Service Bulletin SBF100-57-029, Revision 1,
dated March 23, 1995.
(f) If any cracking or deformation is detected during any
inspection required by this AD, prior to further flight, repair in
accordance with a method approved by the Manager, Standardization
Branch, ANM-113, FAA, Transport Airplane Directorate.
(g) 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, Standardization Branch, ANM-113,
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,
Standardization Branch, ANM-113.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(h) Special flight permits may be issued in accordance with
Secs. 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.
Issued in Renton, Washington, on December 13, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-30746 Filed 12-18-95; 8:45 am]
BILLING CODE 4910-13-U
