[Federal Register Volume 59, Number 49 (Monday, March 14, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-5850]
[[Page Unknown]]
[Federal Register: March 14, 1994]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 93-NM-76-AD]
Airworthiness Directives; Fokker Model F-27 Mark 100, 200, 300,
400, 500, 600, 700, and 800 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 F-27 series
airplanes. This proposal would require the implementation of a
corrosion prevention and control program either by accomplishing
specific tasks or by revising the maintenance inspection program to
include such a program. This proposal is prompted by reports of
incidents involving corrosion and fatigue cracking in transport
category airplanes that are approaching or have exceeded their economic
design goal; these incidents have jeopardized the airworthiness of the
affected airplanes. The actions specified by the proposed AD are
intended to prevent degradation of the structural capabilities of the
airplane due to the problems associated with corrosion.
DATES: Comments must be received by May 9, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 93-NM-76-AD, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056. Comments may be inspected at this location
between 9 a.m. and 3 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: Mark Quam, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-2145; fax (206) 227-1320.
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 93-NM-76-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. 93-NM-76-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
In April 1988, a high-cycle transport category airplane
(specifically, a Boeing Model 737) was involved in an accident in which
the airplane suffered major structural damage during flight.
Investigation of this accident revealed that the airplane had numerous
fatigue cracks and a great deal of corrosion. Subsequent inspections
conducted by the operator on other high-cycle transport category
airplanes in its fleet revealed that other airplanes had extensive
fatigue cracking and corrosion.
Prompted by the data gained from this accident, the FAA sponsored a
conference on aging airplanes in June 1988, which was attended by
representatives from the aviation industry and airworthiness
authorities from around the world. It became obvious that, because of
the tremendous increase in air travel, the relatively slow pace of new
airplane production, and the apparent economic feasibility of operating
older technology airplanes rather than retiring them, increased
attention needed to be focused on the aging airplane fleet and
maintaining its continued operational safety.
The Air Transport Association (ATA) of America and the Aerospace
Industries Association (AIA) of America agreed to undertake the task of
identifying and implementing procedures to ensure the continued
structural airworthiness of aging transport category airplanes. An
Airworthiness Assurance Task Force (AATF) was established in August
1988, with members representing aircraft manufacturers, operators,
regulatory authorities, and other aviation industry representatives
worldwide. The objective of the AATF was to sponsor ``Working Groups''
to:
1. Select service bulletins, applicable to each airplane model in
the transport fleet, to be recommended for mandatory modification of
aging airplanes;
2. Develop corrosion-directed inspections and prevention programs;
3. Review the adequacy of each operator's structural maintenance
program;
4. Review and update the Supplemental Inspection Documents (SID);
and
5. Assess repair quality.
The working group assigned to review the Fokker Model F-27 series
airplanes has completed its work on Item (2) and has developed a
baseline program for controlling corrosion problems that may jeopardize
the continued airworthiness of the Model F-27 fleet. The program is
contained in Fokker Document SE-291, ``F-27 Corrosion Control
Program,'' with revisions through October 1, 1993. (Hereafter, this
publication is referred to as ``the Document.'') The
Rijksluchtvaartdienst (RLD), which is the airworthiness authority for
the Netherlands, classified this Document as mandatory and issued
Netherlands Airworthiness Directive (BLA) 91-113, Issue 2, dated June
26, 1992, in order to assure the continued airworthiness of these
airplanes in The Netherlands.
Section 2.1 of the Document defines three levels of corrosion:
Level l corrosion is that which does not exceed certain limits; Level 2
corrosion is that which exceeds those limits; and Level 3 corrosion is
significant corrosion which is potentially an urgent airworthiness
concern.
Sections 2.2 and 2.3 of the Document provide general guidelines to
develop a corrosion prevention and control program. These guidelines
address such things as a baseline program, implementation ages, access
for inspection, repetitive inspection intervals, operating environment,
newly-acquired airplanes, general cleanliness of the airplane, and the
fact that sampling is unreliable in effectively controlling corrosion.
Section 2.4 of the Document sets forth the general implementation
schedule for the corrosion inspection/control program. As described in
that section, each ``aircraft zone'' is assigned an ``Initial
Inspection Time'' and a ``Repeat Inspection Time.'' The program is
applicable to each aircraft zone on all Model F-27 series airplanes
whose age has reached or exceeded the Initial Inspection Time for that
zone. For airplanes that have not reached or exceeded the Initial
Inspection Time of the specific aircraft zone, a particular inspection
task has to be performed before the airplane has reached the Initial
Inspection Time for the specific aircraft zone, or before the Repeat
Inspection Time of the task is exceeded (a maximum of 6 years),
whichever occurs later. For airplanes that have already reached or
exceeded the Initial Inspection Time of the specific aircraft zone, a
particular inspection has to be performed before the Repeat Inspection
Time of the task is exceeded or within 6 years, whichever occurs first.
Section 2.4 of the Document also identifies the specific aircraft
zones that are subject to the program, and describes the ``basic task''
to be accomplished in each defined aircraft zone as part of the
baseline program, along with the initial inspection time and repeat
inspection time for each area, and other information necessary to carry
out the program for each area. The Document defines a ``basic task'' as
including not only the pertinent visual inspections of all primary and
secondary structures, but any necessary repairs, application of
sealants or corrosion inhibitors, and other follow-on procedures, as
well. A basic task may also include detailed visual and non-destructive
inspections (NDI); where NDI's are employed, adequate standards and
procedures must be developed and properly recorded for the area
inspected.
Section 2.5 establishes the procedures for reporting the results of
the inspections conducted under the corrosion prevention and control
program.
Section 2.6 provides for periodic review and update of the data
contained in the Document.
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 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 corrosion is likely to exist or develop on airplanes of this
type design, an AD is proposed which would require adoption of a
corrosion prevention and control program that is equivalent to or
better than the program specified in the Document previously described.
Operators would be permitted to accomplish this either by performing
the specific basic tasks described in the Document (the ``task-by-task
method''), or by revising their FAA-approved maintenance program to
include such a program.
Paragraph (a) of the proposal sets forth the proposed compliance
times for the initial basic task of each affected aircraft zone. These
compliance times are measured from a date one year after the effective
date of the final rule. (The proposed compliance times are consistent
with those of other similar AD's that the FAA has issued on this
subject.) Generally, operators would be required to complete the
initial basic task before reaching the ``Initial Inspection Time'' plus
one ``Repeat Inspection Time'' interval for the aircraft zone, as
detailed in the Document. The basic task would be required to be
repeated at a time interval not to exceed the ``Repeat Inspection
Time'' interval for that area, as detailed in the Document.
Paragraph (a) includes paragraph (a)(1)(iii), which states that,
for each area that exceeds the initial inspection time for that area,
operators must accomplish the initial basic task at a minimum rate of
one such area every two years, beginning one year after the effective
date of the final rule. The FAA recognizes that this may cause a
hardship on some small operators; in those circumstances, the FAA
anticipates evaluating requests for adjustment to the implementation
rate on a case-by-case basis under the provisions of paragraph (h) of
the proposed rule. (A note to this effect is included in the proposal.)
Operators should note that the proposal does not contain a
paragraph specifically to address repair actions. The FAA considers
that any repairs would be carried out necessarily as a part of each
basic task, as it is defined in the Document. As discussed previously,
a ``basic task'' is defined in the Document as including not only the
pertinent inspection, but any necessary repairs, application of
corrosion inhibitors, and other follow- on procedures, as well.
Paragraph (a) contains a note to reference the portion of the Document
that defines a basic task, and to emphasize the importance of these
corrective actions.
Paragraph (b) of the proposal provides for an optional method of
complying with the rule. In lieu of performing the task-by-task
requirements proposed in paragraph (a), operators may revise their FAA-
approved maintenance/inspection programs to include the corrosion
prevention and control program defined in the Document or an equivalent
program approved by the FAA.
Paragraph (b) also would require that, subsequent to the
accomplishment of the initial basic task, any extensions of Repeat
Inspection Time intervals specified in the Document must be approved by
the FAA.
Any operator electing to comply with proposed paragraph (b) would
be permitted to use an alternative recordkeeping method to that
otherwise required by Federal Aviation Regulations (FAR) section 91.417
or section 121.380, provided it is approved by the FAA and is included
in a revision to the FAA-approved maintenance/inspection program. In
response to questions raised previously concerning recordkeeping and
record retention requirements as they relate to the programmatic
approach proposed in this AD action and other similar proposals that
have been issued applicable to other airplane models, the FAA offers
the following:
Sections 91.417(a)(2)(v) and 121.380(a)(2)(v) of the FAR require
that a record be made of the current status of applicable AD's. With
regard to proposed paragraph (b), such a record would be required to be
made when the maintenance/inspection program is revised to incorporate
the program specified in the Document; at that time, paragraph (b) of
the AD would be fully complied with. Regarding paragraphs (d) through
(g) of this proposal, those paragraphs would impose separate
requirements; therefore, except as discussed below, separate entries
would have to be made to reflect compliance with each of those
paragraphs.
Section 121.380(a)(2)(iv) of the FAR concerns recording ``the
identification of the current inspection status of the aircraft.''
Section 91.417(a)(2)(iv) contains a similar requirement. Because
proposed paragraph (b) would require operators to revise their
maintenance/inspection program to include the program specified in the
Document, each operator's program would be required to identify each
inspection (e.g., ``C'' check) at which each basic task specified in
the Document will be performed on each airplane. By recording the
current inspection status of each airplane, and by maintaining a cross-
reference system between these records and the maintenance/inspection
program revision, it will be possible to determine the current status
of each basic task on each airplane. Once this cross-reference system
has been established, this recording provision of Sections 91 and 121
requires no additional recording beyond what would otherwise be
required normally.
Section 121.380(a)(1) concerns ``records necessary to show that all
requirements for the issuance of an airworthiness release under section
121.709 have been met.'' Section 91.417(a)(1) contains a similar
requirement. These are also referred to as ``dirty fingerprint
records.'' This provision of sections 91 and 121 requires most of the
recording that would result from this proposed AD. Each time a basic
task is performed, the operator would be required to make a ``dirty
fingerprint'' record of the task, identifying what actions were
accomplished. It should be noted, however, that these records are not
different from the records made for any other actions taken under the
operator's maintenance/inspection program.
In addition to the record making requirements, discussed above,
sections 91 and 121 of the FAR impose requirements for record
retention:
Section 121.380(b)(1) and Section 91.417(b)(1) require that the
``dirty fingerprint'' records be retained until the work is repeated or
superseded by other work, or for one year after the work is performed.
Therefore, most of the records resulting from this proposed AD would
not have to be retained indefinitely. However, such retention might
facilitate subsequent transfers, or substantiate requests for
repetitive interval escalations, and therefore, may be in the
operator's interest.
Section 121.380(b)(2) requires that the records specified in
paragraph 121.380(a)(2) [current status of AD's and current inspection
status] be retained and transferred with the airplane at the time it is
sold. Section 91.417(b)(2) contains a similar requirement.
These recording requirements are not considered to be unduly
burdensome and are considered the minimum necessary to enable the
cognizant FAA Maintenance Inspector to perform proper surveillance and
to ensure that the objectives of the proposed rule are being fulfilled.
However, because of the numerous concerns expressed previously by
operators regarding the recordkeeping obligations imposed by section
121.380 with regard to similar rulemaking on corrosion prevention and
control programs, the FAA has included in this proposal certain
provisions for alternative recordkeeping methods. Proposed paragraph
(b)(1) would provide for the development and implementation of such
alternative methods, which must be approved by the FAA. For example,
operators may choose to submit proposals to record compliance with
paragraphs (d) through (g) of the AD by a means other than they
normally use to record AD status. (The FAA has developed guidance
material that will contain information to be considered by FAA
Principal Maintenance Inspectors (PMI) when reviewing proposals for
alternative recordkeeping methods.)
Paragraph (c) of the proposal provides for increasing a ``Repeat
Inspection Time'' interval by up to 10% in order to accommodate
unanticipated scheduling requirements. Operators would be required to
inform the FAA within 30 days of such increases.
Paragraph (d)(1) of the proposal sets forth the reporting actions
that are necessary to be accomplished when Level 3 corrosion is
determined to exist. Within 7 days after such a determination is made,
an operator would be required to accomplish one of the following
actions:
1. Submit a report of the determination to the FAA and complete the
basic task in the affected area on the remainder of the Model F-27
series airplanes in the operator's fleet; or
2. Submit a proposed schedule, for approval by the FAA, for
performing the basic tasks in the affected area on the remainder of the
operator's Model F-27 series fleet; or
3. Submit data substantiating that the Level 3 corrosion was an
isolated occurrence.
Once the FAA has received such a report, it may, in conjunction
with normal surveillance activities, request additional information
regarding the results of the basic tasks performed on the remainder of
the operator's Model F-27 series fleet.
Paragraph (d)(2) of the proposal specifies that the FAA may impose
schedules different from what an operator has proposed under paragraph
(d)(1), if it is found that changes are necessary to ensure that any
other Level 3 corrosion in the operator's Model F-27 series fleet
is detected in a timely manner.
Paragraph (d)(3) of the proposal would require that, within the
time schedule approved by the FAA, the operator must accomplish the
basic tasks in the affected areas on the remaining airplanes in its
Model F-27 series fleet to ensure that any other Level 3 corrosion is
detected.
Paragraph (e) would require that, upon finding corrosion exceeding
Level 1 during a repetitive inspection, an operator must adjust its
program to ensure that future corrosion findings are limited to Level 1
or better. Where corrective action is necessary to reduce corrosion to
Level 1 or better, an operator must submit a proposal for a means of
corrective action for the FAA's approval within 60 days after the
determination of corrosion is made. That means, approved by the FAA,
must then be implemented to reduce future findings of corrosion in that
area to Level 1 or better.
With regard to paragraph (e), it should be noted that if corrosion
is found and it is not considered representative of the operator's
fleet, no further corrective action may be necessary, since a means to
reduce any corrosion to Level 1 or better will have already been
implemented in the operator's program in accordance with proposed
paragraph (a) or (b). For example, if a finding of corrosion is
attributable to a particular spill of mercury or other unique event, or
if corrosion is found on an airplane recently acquired from another
operator, the means specified in the existing program may be adequate
for controlling corrosion in the remainder of the operator's fleet.
Similarly, if an operator has already implemented means to reduce
corrosion in an airplane area based on previous findings, no additional
corrective action may be necessary. In reviewing the reports submitted
in accordance with the AD, the FAA will monitor the effectiveness of
the operator's means to reduce corrosion. If the FAA determines that an
operator has failed to implement adequate means to reduce corrosion to
Level 1 or better, appropriate action will be taken to ensure
compliance with this paragraph.
Paragraph (f) of the proposal concerns adding airplanes to an
operator's fleet, and the procedures that must be followed with regard
to corrosion prevention and control. This paragraph differentiates
between procedures applicable to added airplanes that previously were
maintained in accordance with this AD and those that were not so
maintained. For airplanes that previously have been maintained in
accordance with the proposed requirements of this AD action, the first
basic task in each aircraft zone to be performed by the new operator
would be required to be performed in accordance with either the
previous operator's or the new operator's inspection schedule,
whichever would result in the earlier accomplishment date for that
task. For airplanes that have not been maintained in accordance with
the proposed requirements of this AD action, the first basic task in
each aircraft zone to be performed by the new operator would be
required to be performed before the airplane is placed in service, or
in accordance with a schedule approved by the FAA.
With regard to the requirements of paragraph (f), the FAA considers
it essential that operators ensure that transferred airplanes are
inspected in accordance with the baseline corrosion prevention and
control program on the same basis as if there were continuity in
ownership. Scheduling of the inspections for each airplane must not be
delayed or postponed due to a transfer of ownership; in some cases,
such postponement could continue indefinitely if an airplane is
transferred frequently from one owner to another. The proposed rule
would require that the specified procedures be accomplished before any
operator places into service any airplane subject to the requirements
of the proposed AD.
Paragraph (g) of the proposal would require that reports of Level 2
and Level 3 corrosion be submitted to Fokker within certain time
periods after such corrosion is detected. A note has been included in
this paragraph indicating that reporting to the FAA of any Level 2 or
Level 3 corrosion found as a result of any opportunity inspections is
highly desirable. Operators are not relieved, however, from reporting
corrosion findings as required by FAR section 121.703.
The FAA estimates that 55 airplanes of U.S. registry would be
affected by this proposed AD. It would take an average of approximately
7 work hours per basic task to accomplish the 75 basic tasks called out
in the Document; this represents a total average of 525 work hours. The
average labor rate is $55 per work hour. Based on these figures, the
total cost impact of the proposed AD on U.S. operators for the 6-year
average inspection cycle is estimated to be $1,588,125, or $28,875 per
airplane.
The total 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 FAA recognizes that the obligation to maintain aircraft in an
airworthy condition is vital, but sometimes expensive. Because AD's
require specific actions to address specific unsafe conditions, they
appear to impose costs that would not otherwise be borne by operators.
However, because of the general obligation of operators to maintain
aircraft in an airworthy condition, this appearance is deceptive.
Attributing those costs solely to the issuance of this AD is
unrealistic because, in the interest of maintaining safe aircraft, most
prudent operators would accomplish the required actions even if they
were not required to do so by the AD.
A full cost-benefit analysis has not been accomplished for this
proposed AD. As a matter of law, in order to be airworthy, an aircraft
must conform to its type design and be in a condition for safe
operation. The type design is approved only after the FAA makes a
determination that it complies with all applicable airworthiness
requirements. In adopting and maintaining those requirements, the FAA
has already made the determination that they establish a level of
safety that is cost-beneficial. When the FAA, as in this proposed AD,
makes a finding of an unsafe condition, this means that this cost-
beneficial level of safety is no longer being achieved and that the
proposed actions are necessary to restore that level of safety. Because
this level of safety has already been determined to be cost-beneficial,
a full cost-benefit analysis for this proposed AD would be redundant
and unnecessary.
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 14
CFR part 39 of the Federal Aviation Regulations as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Fokker: Docket 93-NM-76-AD.
Applicability: Model F-27 Mark 100, 200, 300, 400, 500, 600,
700, and 800 series airplanes (does not include Model F-27 MK 050
series airplanes), certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
Note 1: This AD references Fokker Document SE-291, ``F-27
Corrosion Control Program,'' including all revisions through October
1, 1993, (hereafter referred to as ``the Document''), for basic
tasks, definitions of corrosion levels, compliance times, and
reporting requirements. In addition, this AD specifies inspection
and reporting requirements beyond those included in the Document.
Where there are differences between the AD and the Document, the AD
prevails.
Note 2: As used throughout this AD, the term ``the FAA'' is
defined differently for different operators, as follows: For those
operators complying with paragraph (a) of this AD, ``the FAA'' is
defined as ``the Manager of the Standardization Branch, ANM-113,
FAA, Transport Airplane Directorate.'' For those operators operating
under Federal Aviation Regulation (FAR) part 121 or 129, and
complying with paragraph (b) of this AD, ``the FAA'' is defined as
``the cognizant Principal Maintenance Inspector (PMI).'' For those
operators operating under FAR part 91 or 125, and complying with
paragraph (b) of this AD, ``the FAA'' is defined as ``the cognizant
Maintenance Inspector at the appropriate FAA Flight Standards
office.''
Note 3: The FAA recommends that priority for implementing the
corrosion prevention and control program, specified in this AD, be
given to older aircraft and areas requiring a significant upgrade of
previous maintenance procedures to meet the program requirements.
To preclude degradation of the structural capabilities of the
airplane due to the problems associated with corrosion, accomplish
the following:
(a) Except as provided in paragraph (b) of this AD, complete
each of the basic tasks specified in section 2.4 of the Document in
accordance with the procedures of the Document, and the schedule
specified in paragraphs (a)(1) and (a)(2) of this AD.
Note 4: A ``basic task,'' as defined in section 2.4 of the
Document, includes inspections; procedures for a corrective action,
including repairs, under identified circumstances; application of
sealants or corrosion inhibitors; and other follow-on actions.
Note 5: Airplane ``areas'' are those items listed in columnar
form in the ``ACTION'' statement of each task, as listed in the
Document.
Note 6: Basic tasks completed in accordance with the Document
before the effective date of this AD may be credited for compliance
with the initial basic task requirements of paragraph (a)(1) of this
AD.
Note 7: Where non-destructive inspection (NDI) methods are
employed, in accordance with section 2.4 of the Document, the
standards and procedures used must be acceptable to the
Administrator in accordance with FAR section 43.13.
(1) Complete the initial basic task of each aircraft zone
specified in section 2.4 of the Document as follows:
(i) For airplane areas that have not yet exceeded the ``Initial
Inspection Time (IIT)'' for a basic task as of one year after the
effective date of this AD: Initial compliance must occur no later
than the IIT, or no later than one Repeat Inspection Time (RIT)
interval measured from a date one year after the effective date of
this AD, whichever occurs later.
(ii) For airplane areas that have exceeded the IIT for a
particular basic task as of one year after the effective date of
this AD: Initial compliance must occur within one RIT interval for
that task, or within 6 years, measured from a date one year after
the effective date of this AD, whichever occurs first.
(iii) Notwithstanding paragraphs (a)(1)(i) and (a)(1)(ii) of
this AD, accomplish the initial basic task, for each area that
exceeds the IIT for that area, at a minimum rate of one such area
every two years, beginning one year after the effective date of this
AD.
Note 8: This paragraph does not require inspection of any area
that has not exceeded the IIT for that area.
Note 9: This minimum rate requirement may cause an undue
hardship on some small operators. In those circumstances, requests
for adjustments to the implementation rate will be evaluated on a
case-by-case basis under the provisions of paragraph (h) of this AD.
(2) Repeat each basic task at a time interval not to exceed the
RIT interval specified in the Document for that task.
(b) As an alternative to the requirements of paragraph (a) of
this AD: Prior to one year after the effective date of this AD,
revise the FAA-approved maintenance/inspection program to include
the corrosion control program specified in the Document; or to
include an equivalent program that is approved by the FAA. In all
cases, the initial basic task for each airplane area must be
completed in accordance with the compliance schedule specified in
paragraph (a)(1) of this AD.
(1) Any operator complying with paragraph (b) of this AD may use
an alternative recordkeeping method to that otherwise required by
FAR section 91.417 or section 121.380 for the actions required by
this AD, provided it is approved by the FAA and is included in a
revision to the FAA-approved maintenance/inspection program.
(2) Subsequent to the accomplishment of the initial basic task,
extensions of RIT intervals specified in the Document must be
approved by the FAA.
(c) To accommodate unanticipated scheduling requirements, it is
acceptable for an RIT interval to be increased by up to 10%, but not
to exceed 6 months. The FAA must be informed, in writing, of any
such extension within 30 days after such adjustment of the schedule.
(d)(1) If, as a result of any inspection conducted in accordance
with paragraphs (a) or (b) of this AD, Level 3 corrosion is
determined to exist in any airplane area, accomplish either
paragraph (d)(1)(i) or (d)(1)(ii) within 7 days after such
determination:
(i) Submit a report of that determination to the FAA and
complete the basic task in the affected aircraft zones on all Model
F-27 series airplanes in the operator's fleet; or
(ii) Submit to the FAA for approval one of the following:
(A) A proposed schedule for performing the basic tasks in the
affected aircraft zones on the remaining Model F-27 series airplanes
in the operator's fleet, which is adequate to ensure that any other
Level 3 corrosion is detected in a timely manner, along with
substantiating data for that schedule; or
(B) Data substantiating that the Level 3 corrosion found is an
isolated occurrence.
Note: 10: Notwithstanding the provisions of section 2.1 of the
Document, which would permit corrosion that otherwise meets the
definition of Level 3 corrosion (i.e., which is determined to be a
potentially urgent airworthiness concern requiring expeditious
action) to be treated as Level 1 if the operator finds that it ``can
be attributed to an event not typical of the operator's usage of
other airplanes in the same fleet,'' this paragraph requires that
data substantiating any such finding be submitted to the FAA (ref.
Note 2 of this AD) for approval.
(2) The FAA may impose schedules other than those proposed, upon
finding that such changes are necessary to ensure that any other
Level 3 corrosion is detected in a timely manner.
(3) Within the time schedule approved under paragraph (d)(1) or
(d)(2) of this AD, accomplish the basic tasks in the affected
aircraft zones of the remaining Model F-27 series airplanes in the
operator's fleet.
(e) If, as a result of any inspection after the initial
inspection conducted in accordance with paragraph (a) or (b) of this
AD, it is determined that corrosion findings exceed Level 1 in any
area, within 60 days after such determination, implement a means,
approved by the FAA, to reduce future findings of corrosion in that
area to Level 1 or better.
(f) Before any operator places into service any airplane subject
to the requirements of this AD, a schedule for the accomplishment of
basic tasks required by this AD must be established in accordance
with paragraph (f)(1) or (f)(2) of this AD, as applicable:
(1) For airplanes previously maintained in accordance with this
AD, the first basic task in each aircraft zone to be performed by
the new operator must be accomplished in accordance with the
previous operator's schedule or with the new operator's schedule,
whichever would result in the earlier accomplishment date for that
task. After each basic task has been performed once, each subsequent
task must be performed in accordance with the new operator's
schedule.
(2) For airplanes that have not been previously maintained in
accordance with this AD, the first basic task for each aircraft zone
to be performed by the new operator must be accomplished prior to
further flight or in accordance with a schedule approved by the FAA.
(g) Within 7 days after the date of detection of any Level 3
corrosion, and within 3 months after the date of detection of any
Level 2 corrosion, submit a report to Fokker of such findings, in
accordance with section 2.5 of the Document.
Note 11: Reporting to the FAA of Level 2 and Level 3 corrosion
found as a result of any opportunity inspections is highly
desirable.
(h) An alternative method of compliance or adjustment of the
compliance time, which provides an acceptable level of safety, may
be used when approved by the Manager, Standardization Branch, ANM-
113, FAA, Transport Airplane Directorate. Operators shall submit
their requests through the cognizant Maintenance Inspector at the
appropriate FAA Flight Standards office, who may concur or comment
and then send it to the Manager, Standardization Branch, ANM-113.
Note 12: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(i) Special flight permits may be issued in accordance with FAR
21.197 and 21.199 to operate the airplane to a location where the
requirements of this AD can be accomplished.
(j) Reports of inspection results required by this AD 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.
Issued in Renton, Washington, on March 8, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-5850 Filed 3-11-94; 8:45 am]
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