[Federal Register Volume 63, Number 29 (Thursday, February 12, 1998)]
[Proposed Rules]
[Pages 7078-7080]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-3514]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-NM-186-AD]
RIN 2120-AA64
Airworthiness Directives; Fokker F27 Mark 100, 200, 300, 400,
500, 600, and 700 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 F27 Mark 100, 200,
300, 400, 500, 600, and 700 series airplanes. This proposal would
require a modification of the lapjoint below the chine line at certain
fuselage stations. 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
prevent fatigue cracking in the lapjoint below the chine line at
certain fuselage stations, which could result in reduced structural
integrity of the fuselage.
DATES: Comments must be received by March 16, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 96-NM-186-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., Technical Support Department, P.O.
Box 75047, 1117 ZN Schiphol Airport, 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 96-NM-186-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. 96-NM-186-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 certain Fokker F27 Mark 100, 200, 300, 400, 500,
600, and 700 series airplanes. The RLD advises that fatigue analysis of
Fokker Model F27 series airplanes has shown that the lapjoints below
the chine line, between fuselage station 1400 and 16660, are vulnerable
to multiple-site fatigue cracking. Such fatigue cracking occurs when
the airplane is operated, or has been operated, at 5.5 pounds per
square inch (psi) differential cabin pressure, and the affected bottom
fuselage skin panels have a thickness of 0.6 millimeters (mm) (between
fuselage station 1400 and station 12975) or 0.7 mm (between fuselage
station 12975 and station 16660). This condition, if not detected and
corrected in a timely manner, could result in reduced structural
integrity of the fuselage.
Other Relevant Rulemaking
The FAA has previously issued AD 96-13-07, amendment 39-9675 (61 FR
34718, July 3, 1996), which currently requires repetitive inspections
of the subject lapjoints below the chine line of certain fuselage
stations. These inspections are conducted as part of the Fokker Model
F27 Structural Integrity Program (SIP).
This proposed AD will affect items 53-30-02, 53-30-03, and 53-30-04
of the Fokker Model F27 SIP.
[[Page 7079]]
Explanation of Relevant Service Information
Fokker has issued Service Bulletin F27/53-116, dated April 15,
1994, which describes procedures for modification of the lapjoint below
the chine line between fuselage stations 1400 and 16660. The
modification involves the installation of an external doubler on top of
the lapjoint, which would eliminate the need for certain repetitive
inspections required by AD 96-13-07. The RLD classified this service
bulletin as mandatory and issued Dutch airworthiness directive BLA 94-
092 (A), dated May 25, 1994, 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 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 accomplishment of
the actions specified in the service bulletin described previously,
except as described below.
Differences Between the Proposed AD and the Related Dutch AD
Operators should note that, unlike the parallel Dutch airworthiness
directive 94-092(A), dated May 25, 1994, the proposed AD does not
provide for an option for operators to adjust the compliance time
threshold for the subject modification based on the amount of time the
airplane has been operating at a maximum cabin pressure differential of
5.5 psi. The proposed AD would require a fixed threshold for performing
the modifications to the lapjoints. The FAA has determined that such
adjustments would not address the unsafe condition in a timely manner.
However, the FAA acknowledges that the duration of time that the
airplane was operated at 5.5 psi differential pressure is a
contributing factor in determining the appropriate threshold. Paragraph
(d) of the final rule does provide affected operators the opportunity
to apply for an adjustment of the compliance time if data are presented
to justify such an adjustment.
Cost Impact
The FAA estimates that 34 airplanes of U.S. registry would be
affected by this proposed AD.
It would take approximately 140 work hours per airplane to
accomplish the modification (specified as Part 1 in the referenced
service bulletin), at an average labor rate of $60 per work hour. The
cost of required parts would be nominal. Based on these figures, the
cost impact of this modification proposed by this AD on U.S. operators
is estimated to be $8,400 per airplane.
It would take approximately 300 work hours per airplane to
accomplish the modification (specified as Part 2 in the referenced
service bulletin), at an average labor rate of $60 per work hour. The
cost of required parts would be nominal. Based on these figures, the
cost impact of this modification proposed by this AD on U.S. operators
is estimated to be $18,000 per airplane.
It would take approximately 210 work hours per airplane to
accomplish the modification (specified as Part 3 in the referenced
service bulletin), at an average labor rate of $60 per work hour. The
cost of required parts would be nominal. Based on these figures, the
cost impact of this modification proposed by this AD on U.S. operators
is estimated to be $12,600 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 AD were not adopted.
Regulatory Impact
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 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: Docket 96-NM-186-AD.
Applicability: Model F27 Mark 100, 200, 300, 400, 500, 600, and
700 series airplanes, serial numbers 10102 through 10375 inclusive,
that are operated or have been operated at a maximum cabin pressure
differential of 5.5 pounds per square inch (psi), 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 (d) 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 fatigue cracking in the lapjoint below the chine line
at certain fuselage stations, which could result in reduced
structural integrity of the fuselage, accomplish the following:
(a) For airplanes on which Fokker Service Bulletin F27/53-68,
dated July 4, 1966, or Revision 1, dated July 19, 1967, has not been
[[Page 7080]]
accomplished: Prior to the accumulation of 32,000 total flight
cycles, or within 2 years after the effective date of this AD,
whichever occurs later, modify the lapjoint below the chine line
between fuselage station 1400 and station 5050, in accordance with
Part 1 of the Accomplishment Instructions of Fokker Service Bulletin
F27/53-116, dated April 15, 1994. Accomplishment of this
modification and accomplishment of the requirements of paragraph (b)
of this AD, constitutes terminating action for the repetitive
inspection requirements of items 53-30-02 and 53-30-03 of the Fokker
Model F27 Structural Inspection Program (SIP), as required by AD 96-
13-07, amendment 39-9675.
(b) For airplanes on which Fokker Service Bulletin F27/53-85,
dated February 16, 1970, has not been accomplished: Prior to the
accumulation of 32,000 total flight cycles, or within 2 years after
the effective date of this AD, whichever occurs later, modify the
lapjoint below the chine line between fuselage station 5050 and
station 12975, in accordance with Part 2 of the Accomplishment
Instructions of Fokker Service Bulletin F27/53-116, dated April 15,
1994. Accomplishment of this modification and accomplishment of the
requirements of paragraph (a) of this AD, constitutes terminating
action for the repetitive inspection requirements of items 53-30-02
and 53-30-03 of the Fokker Model F27 SIP, as required by AD 96-13-
07.
(c) For airplanes on which Fokker Service Bulletin F27/53-85,
dated February 16, 1970, has not been accomplished: Prior to the
accumulation of 56,000 total flight cycles, or within 2 years after
the effective date of this AD, whichever occurs later, modify the
lapjoint below the chine line between fuselage station 12975 and
station 16660, in accordance with Part 3 of the Accomplishment
Instructions of Fokker Service Bulletin F27/53-116, dated April 15,
1994. Accomplishment of this modification constitutes terminating
action for the repetitive inspection requirements of item 53-30-04
of the Fokker Model F27 SIP, as required by AD 96-13-07.
(d) 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 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.
(e) 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 3: The subject of this AD is addressed in Dutch
airworthiness directive BLA 94-092 (A), dated May 25, 1994.
Issued in Renton, Washington, on February 5, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-3514 Filed 2-11-98; 8:45 am]
BILLING CODE 4910-13-U
