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 Department of Transportation Federal Aviation Administration 14 CFR Part 39
[Docket No. FAA-2011-0318; Directorate Identifier 2010-CE-033-AD]
RIN 2120-AA64
 AGENCY: Federal Aviation Administration (FAA), DOT.
 ACTION: Notice of proposed rulemaking (NPRM).
 SUMMARY: We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD would require repetitive inspections of the upper and lower main wing spar cap angles for cracks and/or corrosion and installing inspection access panels. This AD would also require replacing the wing spar cap angles if moderate or severe corrosion is found and applying corrosion inhibitor. This proposed AD was prompted by reports of intergranular exfoliation and corrosion of the upper and/or lower wing main spar cap angles found on the affected airplanes. We are proposing this AD to detect and correct cracks, intergranular exfoliation and corrosion in the wing main spar cap angles, which could result in reduced strength of the wing spar and the load carrying capacity of the wing. This could lead to wing failure and consequent loss of control.
 DATES: We must receive comments on this proposed AD by May 19, 2011.
 ADDRESSES: You may send comments by any of the following methods: *Federal eRulemaking Portal:*
                         Go to 
                        *http://www.regulations.gov.*
                         Follow the instructions for submitting comments.
                    *Fax:*
                         202-493-2251.
                    *Mail:*
                         U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
                    *Hand Delivery:*
                         Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. For service information identified in this proposed AD, contact Burl's Aircraft, LLC, P.O. Box 671487, Chugiak, Alaska 99567-1487; phone: (907) 688-3715; fax (907) 688-5031; e-mail 
                        *burl@biginalaska.com;*
                         Internet: 
                        *http://www.burlac.com*. You may review copies of the referenced service information at the FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, MO 64106. For information on the availability of this material at the FAA, call (816) 329-4148. Examining the AD Docket You may examine the AD docket on the Internet at 
                    *http://www.regulations.gov;*
                     or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (phone: 800-647-5527) is in the 
                    **ADDRESSES**
                     section. Comments will be available in the AD docket shortly after receipt.
 FOR FURTHER INFORMATION CONTACT: Eric Wright, Aerospace Engineer, FAA, Anchorage Aircraft Certification Office, 222 W. 7th Ave., #14, Anchorage, Alaska 99513; telephone: (907) 271-2648; fax: (907) 271-6365; e-mail: 
                        *eric.wright@faa.gov*.


SUPPLEMENTARY INFORMATION: Comments Invited We invite you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the 
                    **ADDRESSES**
                     section. Include “Docket No. FAA-2011-0318; Directorate Identifier 2010-CE-033-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments. We will post all comments we receive, without change, to 
                    *http://www.regulations.gov,*
                     including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.
                    ( print page 18455) Discussion Since first discovered in 1998, we have received 34 reports of intergranular corrosion and exfoliation found on the upper and lower wing main spar cap angles on Burl A. Rogers Models 15AC and S15AC airplanes. The cause of the corrosion is unknown and does not have a direct correlation to the type, location, or operation performed by the airplane. In the original type design wing skins, there is a lack of access panels, making the main wing spar caps difficult to inspect. If left undetected, the corrosion in the wing main spar caps could become severe enough to reduce the strength of the spar and the load carrying capacity of the wing. This condition, if not corrected, could result in wing failure. This failure could lead to loss of control. Relevant Service Information We have reviewed Burl's Aircraft, LLC Mandatory Service Bulletin No. 15AC06-08-10, dated June 8, 2010. The service information describes procedures for: Inspecting the leading and trailing edges of the upper and lower main wing spar cap angles for cracks, intergranular exfoliation, and corrosion;
                Installing wing inspection access panels;
                Applying corrosion inhibitor on the upper and lower spar cap angles; and
                Replacing the main wing spar cap angles if cracks, intergranular exfoliation, or moderate or severe corrosion is found. Corrosion definitions and limits are contained in FAA Advisory Circular (AC) 43-4A, paragraph 640 (a)(b)(c). FAA's Determination We are proposing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. Proposed AD Requirements This proposed AD would require accomplishing the actions specified in the service information described. Costs of Compliance We estimate that this proposed AD would affect 255 airplanes in the U.S. registry. We estimate the following costs to comply with this proposed AD: Estimated costs
Action
Labor cost
Parts cost
Cost per 
                             product
Cost on U.S. operatorsInitial inspection
10 work-hours × $85 per hour = $850
Not applicable
$850
$216,750Installation of inspection access panels and inspection
30 work-hours × $85 per hour = $2,550
$630
3,180
810,900
 We estimate the following costs to do any necessary replacements that would be required based on the results of the proposed inspections. We have no way of determining the number of aircraft that might need these replacements: On-Condition Costs
Action
Labor cost
Parts cost
Cost per 
                             product per wingReplacement of main spar cap
80 work-hours × $85 per hour = $6,800 per wing
$1,200 per wing
$8,000
 Authority for This Rulemaking Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority. We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. Regulatory Findings We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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. For the reasons discussed above, I certify 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), (3) Will not affect intrastate aviation in Alaska, and (4) 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. List of Subjects in 14 CFR Part 39 Air transportation
Aircraft
Aviation safety
Incorporation by reference
Safety
 The Proposed Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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. § 39.13
  2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD): **Burl A. Rogers (Type Certificate Previously Held by William Brad Mitchell and Aeronca, Inc.) Models 15AC and S15AC 
                                    ( print page 18456)
                                    Airplanes:**
                                 Docket No. FAA-2011-0318; Directorate Identifier 2010-CE-033-AD. Comments Due Date (a) We must receive comments by May 19, 2011. Affected ADs (b) None. Applicability (c) This AD applies to Burl A. Rogers (type certificate previously held by William Brad Mitchell and Aeronca, Inc.) Model 15AC and S15AC airplanes, all serial numbers, that are certificated in any category. Subject (d) Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 57, Wings. Unsafe Condition (e) This AD was prompted by reports of intergranular exfoliation and corrosion of the upper and/or lower wing main spar cap angles found on the affected airplanes. We are issuing this AD to detect and correct cracks and corrosion in the wing main spar cap angles, which could result in reduced strength of the wing spar and the load carrying capacity of the wing. This could lead to wing failure and consequent loss of control. Compliance (f) Comply with this AD within the compliance times specified, unless already done (does not eliminate the repetitive actions of this AD). Actions
Compliance
Procedures(1) Inspect the exposed trailing edges of both the upper and lower main spar cap angles on both the left and right wing for signs of cracks, intergranular exfoliation, and corrosion
Within the next 10 hours time-in-service (TIS) after the effective date of this AD or 3 months after the effective date of this AD, whichever occurs first; or if the left and/or right wing have been repaired and both the upper and lower main spar caps have been replaced using new parts: Inspect at or before the next annual inspection that occurs 10 years after the replacement or within the next 100 hours TIS after the effective date of this AD, whichever occurs later. This compliance time applies separately to each wing
Follow Burl's Aircraft, LLC Mandatory Service Bulletin No. 15AC06-08-10, dated June 8, 2010; and FAA Advisory Circular (AC) 43.13-1B, Change 1, Chapter 6. AC 43.13-1B can be found at 
                                        *http://rgl.faa.gov/​.*(2) After completing the inspection required in paragraph (f)(1) of this AD:(i) Install new inspection hole skin reinforcement doublers and the associated screw cover plate in both the left and right wing
(i) 
                                        *Install inspection hole skin reinforcement doublers:*
                                         Within the next 25 hours TIS after the effective date of this AD or within 6 months after the effective date of this AD, whichever occurs first; or if the left and/or right wing have been repaired and both the upper and lower main spar caps have been replaced using new parts: At or before the next annual inspection that occurs 10 years after the replacement or within the next 100 hours TIS after the effective date of this AD, whichever occurs later. This compliance time applies separately to each wing
Follow Burl's Aircraft, LLC Mandatory Service Bulletin No. 15AC06-08-10, dated June 8, 2010; Burl's Aircraft, LLC Drawing No. SB 15AC06-08-10 (not dated), and FAA Advisory Circular (AC) 43.13-1B, Change 1, Chapter 6. AC 43.13-1B can be found at 
                                        *http://rgl.faa.gov/​.*(ii) Through the inspection access panels, inspect the leading and trailing edges of both the upper and lower main spar cap angles on both the left and right wing for signs of cracks, intergranular exfoliation and corrosion; and
(ii) 
                                        *Inspect:*
                                         Before further flight after installing the inspection hole skin reinforcement doublers(iii) Remove any light corrosion and treat the entirety of both the upper and lower main spar cap angles on both the left and right wing with corrosion inhibitor
(iii) 
                                        *Remove corrosion and treat with corrosion inhibitor:*
                                         Before further flight after the inspection required in paragraph (f)(2)(ii) of this AD(3) If cracks, intergranular exfoliation, or moderate or severe corrosion is found during the inspection required in paragraphs (f)(1) or (f)(2)(ii) of this AD, replace the affected main spar cap angles in their entirety as a single piece. Splicing of the main spar cap angles is not permitted
Before further flight after the inspection required in paragraphs (f)(1) and (f)(2)(ii) of this AD
Follow Burl's Aircraft, LLC Mandatory Service Bulletin No. 15AC06-08-10, dated June 8, 2010; and contact Burl's Aircraft, LLC in paragraph (i) of this AD for a replacement scheme and incorporate the replacement scheme(4) Removing the wing inspection access panels, repetitively inspect both the upper and lower forward main spar caps on both the left and right wing for signs of cracks, intergranular exfoliation, and corrosion
(i) Repetitively thereafter at intervals not to exceed every 12 months after the inspection required in paragraph (f)(2)(ii) of this AD
Follow Burl's Aircraft, LLC Mandatory Service Bulletin No. 15AC06-08-10, dated June 8, 2010; and FAA Advisory Circular (AC) 43.13-1B, Change 1, Chapter 6. AC 43.13-1B can be found at 
                                        *http://rgl.faa.gov/​.*(5) After each inspection required in paragraph (f)(4) of this AD:( print page 18457)(i) If only light corrosion is found, remove the corrosion and treat the main spar cap angles with corrosion inhibitor;
Before further flight after each inspection required in paragraph (f)(4) of this AD. Continue with the repetitive inspections required in paragraph (f)(4) of this AD
Follow Burl's Aircraft, LLC Mandatory Service Bulletin No. 15AC06-08-10, dated June 8, 2010; and FAA Advisory Circular (AC) 43.13-1B, Change 1, Chapter 6. AC 43.13-1B can be found at 
                                        *http://rgl.faa.gov/​.*
                                         Contact Burl's Aircraft, LLC in paragraph (i) of this AD for a replacement scheme and incorporate the replacement scheme.(ii) If cracks, intergranular exfoliation, or moderate or severe corrosion is found, replace the affected main spar cap angles in their entirety as a single piece. Splicing of the main spar cap angles is not permitted(6) Only install main spar cap angles that have been inspected and are free of cracks, intergranular exfoliation, or moderate or severe corrosion
As of the effective date of this AD
Not applicable.
 Alternative Methods of Compliance (AMOCs) (g)(1) The Manager, Anchorage Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the ACO, send it to the attention of the person identified in the Related Information section of this AD. (2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. Related Information (h) For more information about this AD, contact Eric Wright, Aerospace Engineer, FAA, Anchorage ACO, 222 W. 7th Ave., #14, Anchorage, Alaska 99513; telephone: (907) 271-2648; fax: (907) 271-6365; e-mail: 
                                *eric.wright@faa.gov.* (i) For service information identified in this AD, contact Burl's Aircraft, LLC, P.O. Box 671487, Chugiak, Alaska 99567-1487; telephone: (907) 688-3715; fax (907) 688-5031; e-mail 
                                *burl@biginalaska.com*; Internet: 
                                *http://www.burlac.com.*
                                 You may review copies of the referenced service information at the FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, MO 64106. For information on the availability of this material at the FAA, call (816) 329-4148. Issued in Kansas City, Missouri, on March 28, 2011. Earl Lawrence, Manager, Small Airplane Directorate, Aircraft Certification Service.


[FR Doc. 2011-7878 Filed 4-1-11; 8:45 am] BILLING CODE 4910-13-P