Federal Aviation Administration, DOT.
Notice of proposed rulemaking (NPRM).
This document proposes to supersede Airworthiness Directive (AD) 2000-23-01, which applies to all Cessna Aircraft Company (Cessna) Model 402C airplanes. AD 2000-23-01 currently requires repetitive inspections of the forward, aft, and auxiliary wing spars for cracks, and 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 and inspections are necessary on the Model 414A airplanes as well as the Model 402C airplanes. This proposed AD would require you to inspect the wing spar caps for fatigue cracks with any necessary repair or replacement and to incorporate a spar strap modification on each wing spar. 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.
The Federal Aviation Administration (FAA) must receive any comments on this proposed rule on or before August 8, 2003.
Submit comments to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2002-CE-57-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. You Start Printed Page 26245may 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: 9-ACE-7-Docket@faa.gov. Comments sent electronically must contain “Docket No. 2002-CE-57-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, P.O. 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.Start Further Info
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.End Further Info End Preamble Start Supplemental Information
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. 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-57-AD.” We will date stamp and mail the postcard back to you.
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.
Cessna Models 402C and 414A airplanes incorporate a similar design to those airplanes affected by AD 79-10-15 R2. We issued AD 2000-23-01, Amendment 39-11971 (65 FR 70645, November 27, 2000), to require repetitive inspections of the forward, aft, and auxiliary wing spars for cracks on Cessna Models 402C airplanes with repair or replacement as necessary.
There is no similar AD action addressing the Model 414A airplanes.
What has happened since AD 79-10-15 R2 and AD 2000-23-01 to initiate this proposed action? Since issuance of AD 79-10-15 and AD 2000-23-01, 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 402C and 414A 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 Service Bulletin MEB02-05 and Cessna Service Kit SK402-47, both dated June 24, 2002. 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 Models 401, 401A, 401B, 402A, 402B, 411, and 411A airplane is valid;
—The unsafe condition referenced in this document also exists or could develop on Cessna Models 402C and 414A 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 2000-23-01 with a new AD that would apply to Cessna Models 402C and 414A airplanes and would require you to:
—Inspect the wing spar caps for fatigue cracks;
—Repair or replace the wing spar caps as necessary; and
—Incorporate a spar strap modification on each wing spar.
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. Start Printed Page 26246This 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.
How many airplanes would this proposed AD impact? We estimate that this proposed AD affects 656 airplanes in the U.S. registry.
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:
|Labor cost||Parts cost||Total cost per airplane||Total cost on U.S. operators|
|485 workhours × $60 per hour = $29,100 per airplane||$14,000 per airplane||$29,100 + $14,000 = $43,100 per airplane||$43,100 × 656 = $28,273,600.|
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.
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.Start List of Subjects
List of Subjects in 14 CFR Part 39
- Air transportation
- Aviation 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:Start Part
PART 39—AIRWORTHINESS DIRECTIVESEnd Part Start Amendment Part
1. The authority citation for part 39 continues to read as follows:End Amendment Part
2. FAA amends § 39.13 by removing Airworthiness Directive (AD) 2000-23-01, Amendment 39-11971 ( 65 FR 70645, November 27, 2000), and by adding a new AD to read as follows:End Amendment Part
Cessna Aircraft Company: Docket No. 2002-CE-57-AD; Supersedes AD 2000-23-01, Amendment 39-11971.
(a) What airplanes are affected by this AD? This AD affects Models 402C and 414A 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 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 in accordance with Cessna Service Bulletin MEB02-5, dated June 24, 2002, and Cessna Service Kit SK402-47, dated June 24, 2002, as follows:
|Compliance times||Affected airplanes|
|(1) Inspect and modify at whichever of the following that occurs later and repair or replace as necessary prior to further flight after the inspection, unless already accomplished (no repetitive actions necessary):||Cessna Models 402C and 414A airplanes, serial number 414A0001 through 414A0047 and 414A0049 through 414A0200.|
|(i) Upon accumulating 8,500 hours time-in-service (TIS) on a wing spar; or|
|(ii) Within the next 500 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 following that occurs first and repair or replace as necessary prior to further flight after the inspection, unless already accomplished (no repetitive actions necessary):||Cessna Models 402C and 414A airplanes, serial numbers 414A0201 through 414A1212.|
|(i) Upon accumulating 14,500 hours TIS on a wing spar; or|
|(ii) Within the next 500 hours TIS after the effective date of this AD or 12 months after the effective date of this AD, whichever occurs first|
(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 2000-23-01 and AD 99-11-13 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 Start Printed Page 26247the documents referenced in this AD from the Cessna Aircraft Company, Product Support, P.O. 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 2000-23-01, Amendment 39-11971.Start Signature
Issued in Kansas City, Missouri, on May 9, 2003.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 03-12111 Filed 5-14-03; 8:45 am]
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