[Federal Register Volume 62, Number 24 (Wednesday, February 5, 1997)]
[Proposed Rules]
[Pages 5350-5355]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-2851]


      
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Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

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Federal Register / Vol. 62, No. 24 / Wednesday, February 5, 1997 / 
Proposed Rules

[[Page 5350]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-123-AD]
RIN 2120-AA64


Airworthiness Directives; Construcciones Aeronauticas, S.A. 
(CASA) Model C-212 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 all CASA C-212 series airplanes. 
This proposal would require the implementation of a corrosion 
prevention and control program either by accomplishing specific 
inspections 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 March 17, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-123-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 Construcciones Aeronauticas, S.A., Getafe, Madrid, Spain. 
This information may be examined at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Greg Dunn, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2799; 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 96-NM-123-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. 96-NM-123-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion: Background

    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 
continuing to operate older technology airplanes rather than retire 
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 Working Group (AAWG) was established in August 
1988, with members representing aircraft manufacturers, operators, 
regulatory authorities, and other aviation industry representatives 
worldwide. The objective of the AAWG was to sponsor 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.

Development of Relevant Service Document

    CASA has completed its work on Item 2 and has developed a baseline 
program

[[Page 5351]]

for controlling corrosion on the CASA Model C-212 fleet. The program is 
contained in CASA Document CPCP C-212-PV01, ``C-212 Corrosion 
Prevention and Control Program Document,'' dated March 31, 1995. 
(Hereafter, this publication is referred to as ``the Document.'') The 
Direccion General de Aviacion (DGAC), which is the airworthiness 
authority for Spain, classified this Document as mandatory and issued 
Spanish Airworthiness Directive 01/96, dated April 30, 1996, in order 
to assure the continued airworthiness of these airplanes in Spain.

Detailed Description of the Document

    Section 2 of the Document defines three levels of corrosion: Level 
1 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.
    Section 4 of the Document provides general rules for developing and 
applying a corrosion prevention and control program. Among other 
things, these guidelines provide an outline of the baseline program, a 
general description of ``Implementation Ages'' and (repetitive) 
``Intervals,'' and description of situations necessitating a fleet 
inspection.
    Section 5 addresses establishing a ``baseline program,'' whose main 
objective is to control corrosion to a Level 1 or better. Specifically:
    Section 5.1. describes the procedures that entail each of the 
corrosion inspections to be accomplished in each area of the airplane 
zones as part of the baseline program. As defined in this section, a 
``corrosion inspection'' includes, among other actions:
    a. Gaining access for inspection,
    b. Performing the actual inspection for corrosion,
    c. Removing corrosion,
    d. Clearing blocked drains, and
    e. Applying corrosion inhibitors and/or water displacement fluid.
    Section 5.2. describes the baseline program instructions, including 
an explanation of the form used to describe the program and a 
definition of the ``levels of inspection'' to be accomplished. The 
different inspection levels defined are: General Visual Inspection 
(GVI), Detailed Inspection (DET), and Special Detailed Inspection 
(SDET).
    Section 5.3. contains the baseline corrosion and prevention and 
control program, including description of each airplane zone, 
description of the areas of each airplane zone to be inspected, the 
inspection level, the Implementation Age (IA), and the (repeat) 
Interval. Unless otherwise indicated, the inspections of each aircraft 
zone are required on all CASA Model C-212 series airplanes whose age 
has reached or exceeded the IA specified for that area. For airplanes 
that have not reached or exceeded the IA of the specific area, the 
particular inspection has to be performed before the airplane has 
reached the IA for the specific area, or before the (repeat) Interval 
of the inspection area is exceeded. For airplanes that have already 
reached or exceeded the IA of the specific area, the particular 
inspection has to be performed before the (repeat) Interval of the 
inspection is exceeded.
    Section 6 of the Document includes a flow diagram that provides 
guidance for determining the level of corrosion detected during the 
required inspections of airplane zones.
    Section 7 of the Document establishes the procedures for reporting 
to CASA the results of the inspections conducted under the corrosion 
prevention and control program.
    Section 8 of the Document contains a glossary of terms and 
definitions. The Document also contains appendices that provide 
guidelines for evaluating corrosion damage.

FAA's Conclusion

    This airplane model is manufactured in Spain 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 DGAC has kept the FAA informed of the 
situation described above. The FAA has examined the findings of the 
DGAC, 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 Proposed Requirements of the Rule

    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 inspections described in the Document (the ``task-by-task 
method''), or by revising their FAA-approved maintenance program to 
include such a program.

Paragraph (a): Option 1, The Task-by-Task Method

    Paragraph (a) of the proposal sets forth the proposed compliance 
times for the initial corrosion inspections of each area of the 
affected airplane zones. 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 inspection before reaching the IA for 
the area, as detailed in the Document. The inspection would be required 
to be repeated at a time interval not to exceed the (repeat) Interval 
for that area, as detailed in the Document.
    Paragraph (a) includes paragraph (a)(1)(iv), which states that, 
once the initial compliance period has been established for each 
airplane area, accomplishment of the initial inspections by each 
operator must occur at a minimum rate equivalent to one airplane per 
year, 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 
inspection action, as it is defined in the Document. As discussed 
previously, the procedures that entail a ``corrosion inspection,'' as 
defined in Section 5.1. of the Document, include not only the 
inspection itself, 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 
an inspection, and to emphasize the importance of these corrective 
actions.

Paragraph (b): Option 2, Revising the Maintenance Program

    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.

[[Page 5352]]

Recordkeeping Under Option 2

    Paragraph (b) also would require that, subsequent to the 
accomplishment of the initial inspection, any extensions of the repeat 
inspection 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 inspection 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 required inspection on each airplane. Once this cross-reference 
system has been established, this recording provision of FAR sections 
91 and 121 requires no additional recording beyond what would otherwise 
be required normally.
    Section 121.380(a)(1) of the FAR concerns ``records necessary to 
show that all requirements for the issuance of an airworthiness release 
under FAR 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 an inspection is performed in accordance with the corrosion 
prevention and control program, 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:
    FAR sections 121.380(b)(1) and 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): Increasing Inspection Intervals

    Paragraph (c) of the proposal provides for increasing the IA or 
(repeat) Interval by up to 10% (but not to exceed 3 months) in order to 
accommodate unanticipated scheduling requirements. Operators would be 
required to inform the FAA within 30 days of such increases.
    This provision is intended to provide flexibility to operators in 
the maintenance scheduling of individual airplanes on a case-by-case 
basis. It is not intended to allow operators to escalate repetitive 
inspection intervals for their entire fleets.

Paragraph (d): Reporting Requirements

    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 on an airplane in the operator's fleet, the 
operator would be required to accomplish one of the following actions 
within 7 days after such a determination is made:
    1. submit a report of the determination to the FAA and conduct the 
relevant corrosion inspection in the affected area on the remainder of 
the Model C-212 series airplanes in the operator's fleet (within the 7-
day period); or
    2. submit, for approval by the FAA, either:

--A proposed schedule for performing the relevant corrosion inspection 
in the affected area on the remainder of the operator's Model C-212 
series fleet; or
--Data substantiating that the Level 3 corrosion was an isolated 
occurrence.

    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 C-212 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

[[Page 5353]]

operator must accomplish the inspections in the affected areas on the 
remaining airplanes in its Model C-212 series fleet to ensure that any 
other Level 3 corrosion is detected.

Paragraph (e): Procedures for Adjusting the Program

    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 30 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): Provisions Regarding Newly Acquired Airplanes

    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 
inspection in each airplane area 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 inspection in 
each airplane area 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): Reporting Level 2 and Level 3 Corrosion Findings

    Paragraph (g) of the proposal would require that reports of Level 2 
and Level 3 corrosion be submitted to CASA within certain time periods 
after such corrosion is detected. Operators are not relieved, however, 
from reporting corrosion findings as required by FAR section 121.703 
(14 CFR 121.703).

Cost Impact

     The FAA estimates that 41 airplanes of U.S. registry would be 
affected by this proposed AD. It would take an average of approximately 
7 work hours per inspection to accomplish the inspections of the 59 
airplane areas called out in the Document; this represents a total 
average of 413 work hours. The average labor rate is $60 per work hour. 
Based on these figures, the cost impact of the proposed AD on U.S. 
operators over a 4-year average inspection cycle is estimated to be 
$1,015,980, or $24,780 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 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 the original 
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.

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

[[Page 5354]]

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:

CASA: Docket 96-NM-123-AD.

    Applicability: All Model C-212 series airplanes, certificated in 
any category.
    Compliance: Required as indicated, unless accomplished 
previously.

    Note 1: This AD references CASA Document Number CPCP C-212-
PV01,``Corrosion Prevention and Control Program Document,'' dated 
March 31, 1995, for inspections, 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), OPTION 1, 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 Regulations 
(FAR) part 121 or 129 (14 CFR part 121 or part 129), and complying 
with paragraph (b), OPTION 2, of this AD, the FAA is defined as 
``the cognizant Principal Maintenance Inspector (PMI).''
--For those operators operating under FAR part 91 or 125 (14 CFR 
part 91 or part 125), and complying with paragraph (b), OPTION 2, of 
this AD, the FAA is defined as ``the cognizant Maintenance Inspector 
at the appropriate FAA Flight Standards office.''

    To prevent degradation of the structural capabilities of the 
airplane due to the problems associated with corrosion damage, 
accomplish the following:
    (a) Option 1. Except as provided in paragraph (b) of this AD: 
Complete each of the corrosion inspections specified in section 5.3 
of CASA Document Number CPCP C-212-PV01, ``Corrosion Prevention and 
Control Program Document,'' dated March 31, 1995 (hereafter, 
referred to as ``the Document), in accordance with the procedures 
defined in the Document and the schedule specified in paragraphs 
(a)(1) and (a)(2) of this AD.

    Note 3: A ``corrosion inspection'' as defined in Section 5.1. of 
the Document includes, among other things, gaining access for 
inspection, performing the actual inspection for corrosion, removing 
corrosion, clearing blocked drains, applying corrosion inhibitors 
and/or water displacement fluid, and other follow-on actions.
    Note 4: Corrosion inspections completed in accordance with the 
Document before the effective date of this AD may be credited for 
compliance with the initial corrosion inspection requirements of 
paragraph (a)(1) of this AD.
    Note 5: Where non-destructive inspection (NDI) methods are 
employed when performing a Special Detailed Inspection (DET), in 
accordance with Section 5.3 of the Document, the standards and 
procedures used must be acceptable to the FAA Administrator in 
accordance with FAR section 43.13 (14 CFR section 43.13).

    (1) Complete the initial corrosion inspection of each area of 
each airplane zone specified in Section 5.3 of the Document as 
follows:
    (i) For airplane areas that have not yet reached the 
``Implementation Age'' (IA) as of one year after the effective date 
of this AD, initial compliance must occur no later than the IA plus 
the (repeat) ``Interval.''
    (ii) For airplane areas that have exceeded the IA as of one year 
after the effective date of this AD, initial compliance must occur 
within the (repeat) Interval for the area, measured from a date one 
year after the effective date of this AD.
    (iii) For airplanes that are 15 years or older as of one year 
after the effective date of this AD, initial compliance must occur 
for all airplane areas within one (repeat) Interval, or within 4 
years, measured from a date one year after the effective date of 
this AD, whichever occurs first.
    (iv) Notwithstanding paragraphs (a)(i)(i), (a)(1)(ii), and 
(a)(1)(iii), in all cases, once the initial compliance period has 
been established for each airplane area, accomplishment of the 
initial corrosion inspections by each operator must occur at a 
minimum rate equivalent to one airplane per year.

    Note 6: This minimum rate requirement may cause a 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 provision of paragraph (h) of this AD.

    (2) Repeat each corrosion inspection at a time interval not to 
exceed the (repeat) Interval specified in the Document for that 
inspection.
    (b) Option 2. 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 prevention and control program specified in 
the Document; or to include an equivalent program that is approved 
by the FAA. In all cases, the initial corrosion inspection of 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 (14 CFR 91.417) or section 12.380 (14 CFR 
121.380) for the actions required by this AD, provided it is 
approved by the FAA and is included a revision to the FAA-approved 
maintenance/inspection program.
    (2) Subsequent to the accomplishment of the initial corrosion 
inspection, extensions of the (repeat) Intervals specified in the 
Document must be approved by the FAA.
    (c) To accommodate unanticipated scheduling requirements, it is 
acceptable for a (repeat) Interval to be increased by up to 10%, but 
not to exceed 3 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 corrosion inspection conducted in 
accordance with paragraph (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) of this AD within 7 days after 
such determination:
    (i) Submit a report of that determination to the FAA and 
complete the corrosion inspection in the affected airplane area(s) 
on all Model C-212 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 corrosion 
inspection(s) in the affected airplane area(s) on the remaining 
Model C-212 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 7: Notwithstanding the provisions of Section 2 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 
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.

[[Page 5355]]

    (3) Within the time schedule approved under paragraph (d)(1) or 
(d)(2) of this AD, accomplish the corrosion inspections in the 
affected airplane areas of the remaining Model C-212 series 
airplanes in the operator's fleet.
    (e) If, as a result of any inspection after the initial 
corrosion 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 30 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 newly acquired 
airplane that is subject to the requirements of this AD, a schedule 
for the accomplishment of the corrosion inspections required by this 
AD must be established in accordance with either paragraph (f)(1) or 
(f)(2) of the AD, as applicable:
    (1) For airplanes previously maintained in accordance with this 
AD, the first corrosion inspection in each airplane area to be 
performed by the operator must be accomplished in accordance with 
either the previous operator's schedule or the new operator's 
schedule, whichever would result in the earlier accomplishment date 
for that inspection. After each corrosion inspection has been 
performed once, each subsequent inspection 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 corrosion inspection for each 
airplane area 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 CASA of such findings, in 
accordance with Section 7 of the Document.
    (h) 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 8: 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 
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.

    Issued in Renton, Washington, on January 30, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-2851 Filed 2-4-97; 8:45 am]
BILLING CODE 4910-13-U