[Federal Register Volume 68, Number 94 (Thursday, May 15, 2003)]
[Proposed Rules]
[Pages 26239-26242]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-12113]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-CE-05-AD]
RIN 2120-AA64


Airworthiness Directives; Cessna Aircraft Company Models 401, 
401A, 401B, 402, 402A, 402B, 411, and 411A Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to supersede Airworthiness Directive 
(AD) 79-10-15 R2, which applies to all Cessna Aircraft Company (Cessna) 
Models 401, 401A, 401B, 402, 402A, 402B, 411, and 411A airplanes. AD 
79-10-15 R2 currently requires repetitive inspections of the right and 
left wing spar lower cap areas for fatigue cracks and requires wing 
spar cap repair or replacement as necessary. Cessna has performed 
fatigue and crack growth analyses of the wings of these airplanes, and 
the Federal Aviation Administration (FAA) has evaluated this 
information and determined that a wing spar modification is necessary 
as well as periodic inspections. This proposed AD would require you to 
repetitively inspect the wing spar caps for fatigue cracks with any 
necessary repair or replacement on all airplanes and incorporate a spar 
strap modification on each wing spar on certain airplanes. The actions 
specified by this proposed AD are intended to prevent wing spar cap 
failure due to undetected fatigue cracks. Such failure could result in 
loss of a wing with consequent loss of airplane control.

DATES: The FAA must receive any comments on this proposed rule on or 
before August 8, 2003.

ADDRESSES: Submit comments to FAA, Central Region, Office of the 
Regional Counsel, Attention: Rules Docket No. 2002-CE-05-AD, 901 
Locust, Room 506, Kansas City, Missouri 64106. You may view any 
comments at this location between 8 a.m. and 4 p.m., Monday through 
Friday, except Federal holidays. You may also send comments 
electronically to the following address: [email protected]. 
Comments sent electronically must contain ``Docket No. 2002-CE-05-AD'' 
in the subject line. If you send comments electronically as attached 
electronic files, the files must be formatted in Microsoft Word 97 for 
Windows or ASCII text.
    You may get service information that applies to this proposed AD 
from the Cessna Aircraft Company, Product Support, PO Box 7706, 
Wichita, Kansas 67277; telephone: (316) 517-5800; facsimile: (316) 942-
9006. You may also view this information at the Rules Docket at the 
address above.

FOR FURTHER INFORMATION CONTACT: Paul Nguyen, Aerospace Engineer, FAA, 
Wichita Aircraft Certification Office, 1801 Airport Road, Mid-Continent 
Airport, Wichita, Kansas 67209; telephone: (316) 946-4125; facsimile: 
(316) 946-4107.

SUPPLEMENTARY INFORMATION:

Comments Invited

How Do I Comment on This Proposed AD?

    The FAA invites comments on this proposed rule. You may submit 
whatever written data, views, or arguments you choose. You need to 
include the rule's docket number and submit your comments to the 
address specified under the caption ADDRESSES.

[[Page 26240]]

We will consider all comments received on or before the closing date. 
We may amend this proposed rule in light of comments received. Factual 
information that supports your ideas and suggestions is extremely 
helpful in evaluating the effectiveness of this proposed AD action and 
determining whether we need to take additional rulemaking action.

Are There Any Specific Portions of This Proposed AD I Should Pay 
Attention to?

    The FAA specifically invites comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed rule that 
might suggest a need to modify the rule. You may view all comments we 
receive before and after the closing date of the rule in the Rules 
Docket. We will file a report in the Rules Docket that summarizes each 
contact we have with the public that concerns the substantive parts of 
this proposed AD.

How Can I Be Sure FAA Receives My Comment?

    If you want FAA to acknowledge the receipt of your mailed comments, 
you must include a self-addressed, stamped postcard. On the postcard, 
write ``Comments to Docket No. 2002-CE-05-AD.'' We will date stamp and 
mail the postcard back to you.

Discussion

Has FAA Taken Any Action to This Point?

    Reports of fatigue cracks on Cessna 401, 402, and 411 series 
airplanes caused FAA to take AD action (AD 79-10-15 R2, Amendment 39-
3711) to require repetitive inspections of the right and left wing spar 
lower cap areas for fatigue cracks and to require wing spar cap repair 
or replacement as necessary.
    Accomplishment of the inspections required by AD 79-10-15 R2 is 
required in accordance with Cessna Service Bulletin ME79-16, Revision 
3, dated February 8, 1980.
    AD 79-10-15 R2 allowed for the incorporation of Cessna Service Kit 
SK402-36 or SK411-56 on the front wing spar lower cap as terminating 
action for the repetitive inspections on the applicable wing.

What Has Happened Since AD 79-10-15 R2 To Initiate This Proposed 
Action?

    Since issuance of AD 79-10-15, Cessna has analyzed the wing, 
including fatigue and crack growth analyses, on the affected airplanes. 
Analysis included:

--A determination of the probable location and modes of damage based on 
analytical results, available test data, and service information;
--Classical fatigue analyses;
--Crack growth and residual strength analyses including use of linear 
elastic fracture mechanics methods;
--Full-scale ground testing to validate analytical models; and
--A flight strain survey to develop stress spectra used in the 
analyses.

    The inspections required by AD 79-10-15 R2 in accordance with 
Cessna Service Bulletin ME79-16, Revision 3, are accomplished using a 
surface eddy current inspection method.
    Based on the analysis, Cessna has found that the eddy current 
method will not find the crack until it is .03 inch longer than the 
critical crack length. When the crack reaches the critical length, it 
is not reliably detectable because it is under the head of the 
fastener. Once the main spar cap is severed, the remaining structure 
will no longer meet the residual strength requirements. Wing separation 
could then occur under loading conditions significantly less than those 
established for the design limit load.
    Cessna reported only one instance where cracks were detected using 
the nondestructive inspection (NDI) eddy current procedure. There are 
other reported instances where cracks were detected visually in the 
wheel well area on the aft flange. The problem with visual inspections 
is the access doubler flanges cover a large percentage of the forward 
spar flange. This limits the effectiveness of the visual inspections.
    To meet industry NDI standards, cracks need to be found on Cessna 
Models 401, 401A, 401B, 402, 402A, 402B, 411, and 411A airplanes 
through NDI inspection methods with a 90-percent probability of 
detection at a 95-percent confidence level.
    Cessna's analysis indicates that the probability and confidence 
levels are not being met.

Is There Service Information That Applies to This Subject?

    Cessna has issued the following:

--Service Bulletin MEB01-06 and Service Kit SK402-46, both dated 
September 24, 2001; and
--Service Bulletin MEB01-07 and Service Kit SK411-59, both dated 
September 24, 2001.

    This service information includes procedures for inspecting and 
modifying the lower wing spar caps.

The FAA's Determination and an Explanation of the Provisions of This 
Proposed AD

What Has FAA Decided?

    After examining the circumstances and reviewing all available 
information related to the incidents described above, we have 
determined that:

--Cessna's analysis of the problems with the eddy current inspection on 
the wing spar cap area on the Cessna 401, 402, and 411 series airplanes 
is valid;
--The unsafe condition referenced in this document exists or could 
develop on these airplanes that are the same type design;
--The actions specified in the previously-referenced service 
information should be accomplished on the affected airplanes; and
--AD action should be taken in order to correct this unsafe condition.

What Would This Proposed AD Require?

    This proposed AD would supersede AD 79-10-15 R2 with a new AD that 
would require you to either (depending on the aircraft configuration):

--For airplanes that do not incorporate one of certain Cessna Service 
Kits: repetitively inspect the wing spar caps for fatigue cracks and 
repair or replace the wing spar caps as necessary and incorporate a 
spar strap modification on each wing spar; or
--For airplanes that incorporate one of certain Cessna Service Kits: 
repetitively inspect the wing spar caps for fatigue cracks and repair 
or replace the wing spar caps as necessary.

How Does the Revision to 14 CFR Part 39 Affect This Proposed AD?

    On July 10, 2002, FAA published a new version of 14 CFR part 39 (67 
FR 47997, July 22, 2002), which governs FAA's AD system. This 
regulation now includes material that relates to special flight 
permits, alternative methods of compliance, and altered products. This 
material previously was included in each individual AD. Since this 
material is included in 14 CFR part 39, we will not include it in 
future AD actions.

Cost Impact

How Many Airplanes Would This Proposed AD Impact?

    We estimate that this proposed AD affects 400 airplanes in the U.S. 
registry.

[[Page 26241]]

What Would Be the Cost Impact of This Proposed AD on Owners/Operators 
of the Affected Airplanes?

    We estimate the following costs to accomplish the proposed 
modification and initial inspection:

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                                                                   Total cost  per         Total cost on  U.S.
             Labor cost                      Parts cost                airplane                 operators
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485 workhours x $60 per hour =        $1,763 per airplane....  $29,100 + $1,763 =       $30,863 x 400 =
 $29,100 per airplane.                                          $30,863 per airplane.    $12,345,200.
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    The above figures do not take into account the cost of repetitive 
inspections. The FAA does not have any way of determining the number of 
repetitive inspections each owner/operator would incur during the 
operating life of the affected airplanes.

Regulatory Impact

Would This Proposed AD Impact Various Entities?

    The regulations proposed herein would not have a substantial direct 
effect on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, it 
is determined that this proposed rule would not have federalism 
implications under Executive Order 13132.

Would This Proposed AD Involve a Significant Rule or Regulatory Action?

    For the reasons discussed above, I certify that this proposed 
action (1) is not a ``significant regulatory action'' under Executive 
Order 12866; (2) is not a ``significant rule'' under 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 has been placed 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, under 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. FAA amends Sec.  39.13 by removing Airworthiness Directive (AD) 
79-10-15 R2, Amendment 39-3711, and by adding a new AD to read as 
follows:

Cessna Aircraft Company: Docket No. 2002-CE-05-AD; Supersedes AD 79-
10-15 R2, Amendment 39-3711.

    (a) What airplanes are affected by this AD? This AD affects 
Models 401, 401A, 401B, 402, 402A, 402B, 411, and 411A airplanes, 
all serial numbers, that are certificated in any category.
    (b) Who must comply with this AD? Anyone who wishes to operate 
any of the airplanes identified in paragraph (a) of this AD must 
comply with this AD.
    (c) What problem does this AD address? The actions specified by 
this AD are intended to prevent wing spar cap failure due to 
undetected fatigue cracks. Such failure could result in loss of a 
wing with consequent loss of airplane control.
    (d) What actions must I accomplish to address this problem? To 
address this problem, you must repetitively inspect the wing spar 
caps for fatigue cracks and repair or replace the wing spar caps as 
necessary and incorporate a spar strap modification (as specified) 
on each wing spar in accordance with Cessna Service Bulletin MEB01-6 
and Cessna Service Kit SK402-46, both dated September 24, 2001; or 
Cessna Service Bulletin MEB01-7 and Cessna Service Kit SK411-59, 
both dated September 24, 2001, as follows:

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  Initial and repetitive compliance times        Affected airplanes
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(1) Inspect and modify at whichever of the  Cessna Models 411 and 411A
 following that occurs later and repair or   airplanes that do not
 replace as necessary prior to further       incorporate Cessna Service
 flight after the inspection, unless         Kit SK411-56, SK411-56A, or
 already accomplished, and repetitively      SK411-56B.
 inspect at the intervals specified in
 paragraphs (d)(3)(i), (d)(3)(ii), and
 (d)(3)(iii) of this AD:
(i) Upon accumulating 5,500 hours time-in-
 service (TIS) on a wing spar; or.
(ii) Within the next 200 hours TIS after
 the effective date of this AD or 12
 months after the effective date of this
 AD, whichever occurs first..
(2) Inspect and modify at whichever of the  Cessna Models 401, 401A,
 following that occurs first and repair or   401B, 402, 402A, and 402B
 replace as necessary prior to further       airplanes that do not
 flight after the inspection, unless         incorporate Cessna Service
 already accomplished, and repetitively      or Kit SK402-36, SK402-36A,
 inspect at the intervals specified in       (SK402-36B, or SK402-36C.
 paragraphs (d)(4)(i) and (d)(4)(ii) of
 this AD:
(i) Upon accumulating 6,500 hours TIS on a
 wing spar; or.
(ii) Within the next 200 hours TIS after
 the effective date of this AD or 12
 months after the effective date of this
 AD, whichever occurs first..

[[Page 26242]]

 
(3) Inspect in the following areas          Cessna Models 411 and 411A
 (modification not required for these        airplanes that incorporate
 airplanes) and repair or replace as         Cessna Service Kit SK411-
 necessary prior to further flight after     56, SK411-56A, SK411-56B,
 the inspection where cracks are found.      or SK411-59. This includes
 Inspection areas are defined in the         airplanes that had Cessna
 Cessna Model 411 Supplemental Inspection    Service Kit SK411-59
 Document (SID):                             incorporated as required by
(i) Area ``A'' (Inspection ID 57-10-11):     paragraph (d)(1) of this
 Initially upon accumulating 5,400 hours     AD.
 TIS after incorporating the applicable
 service kit on a wing spar or within the
 next 100 hours TIS after the effective
 date of this AD, whichever occurs later,
 unless already accomplished, and
 thereafter at intervals not to exceed
 2,500 hours TIS..
(ii) Area ``B'' (Inspection ID 57-10-12):
 Initially upon accumulating 5,400 hours
 TIS after incorporating the applicable
 service kit on a wing spar or within the
 next 100 hours TIS after the effective
 date of this AD, whichever occurs later,
 unless already accomplished, and
 thereafter at intervals not to exceed
 1,000 hours TIS..
(iii) Area ``C'' (Inspection ID 57-10-08):
 Upon accumulating 19,900 hours TIS after
 incorporating the applicable service kit
 on a wing spar or within the next 100
 hours TIS after the effective date of
 this AD, whichever occurs later, unless
 already accomplished, and thereafter at
 intervals not to exceed 2,000 hours TIS..
(4) Inspect in the following areas          Cessna Models 401, 401A,
 (modification not required for these        401B, 402, 402A, and 402B
 airplanes) and repair or replace as         airplanes that incorporate
 necessary prior to further flight after     Cessna Service Kit SK402-
 the inspection. Inspection areas are        36, SK402-36A, SK402-36B,
 defined in the Cessna Model 401/402         SK402-36C, or SK402-46.
 Supplemental Inspection Document (SID):     This includes airplanes
(i) Area ``A'' (Inspection ID 57-10-11)      that had Cessna Service Kit
 and Area ``B'' (Inspection ID 57-10-12):    SK402-46 incorporated as
 Initially upon accumulating 7,400 hours     required by paragraph
 TIS after incorporating the applicable      (d)(2) of this AD.
 service kit on a wing spar or within the
 next 100 hours TIS after the effective
 date of this AD, whichever occurs later,
 unless already accomplished, and
 thereafter at intervals not to exceed
 5,000 hours TIS..
(ii) Area ``C'' (Inspection ID 57-10-08):
 Initially upon accumulating 19,900 hours
 TIS after incorporating the applicable
 service kit on a wing spar or within the
 next 100 hours TIS after the effective
 date of this AD, whichever occurs later,
 unless already accomplished, and
 thereafter at intervals not to exceed
 2,500 hours TIS..
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    (e) Can I comply with this AD in any other way?
    (1) To use an alternative method of compliance or adjust the 
compliance time, follow the procedures in 14 CFR 39.19. Send these 
requests to the Manager, Wichita Aircraft Certification Office 
(ACO). For information on any already approved alternative methods 
of compliance, contact Paul Nguyen, Aerospace Engineer, FAA, Wichita 
Aircraft Certification Office, 1801 Airport Road, Mid-Continent 
Airport, Wichita, Kansas 67209; telephone: (316) 946-4125; 
facsimile: (316) 946-4107.
    (2) Alternative methods of compliance approved in accordance 
with AD 79-10-15 R2, which is superseded by this AD, are not 
approved as alternative methods of compliance with this AD.
    (f) How do I get copies of the documents referenced in this AD? 
You may get copies of the documents referenced in this AD from the 
Cessna Aircraft Company, Product Support, PO Box 7706, Wichita, 
Kansas 67277; telephone: (316) 517-5800; facsimile: (316) 942-9006. 
You may view these documents at FAA, Central Region, Office of the 
Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.
    (g) Does this AD action affect any existing AD actions? This 
amendment supersedes AD 79-10-15 R2, Amendment 39-3711.

    Issued in Kansas City, Missouri, on May 9, 2003.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-12113 Filed 5-14-03; 8:45 am]
BILLING CODE 4910-13-P