
[Federal Register Volume 76, Number 64 (Monday, April 4, 2011)]
[Proposed Rules]
[Pages 18454-18457]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-7878]


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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


Airworthiness Directives; Burl A. Rogers (Type Certificate 
Previously Held by William Brad Mitchell and Aeronca, Inc.) Models 15AC 
and S15AC Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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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.

[[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
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
              Action                      Labor cost             Parts cost           product        operators
----------------------------------------------------------------------------------------------------------------
Initial inspection................  10 work-hours x $85    Not applicable.......            $850        $216,750
                                     per hour = $850.
Installation of inspection access   30 work-hours x $85    $630.................           3,180         810,900
 panels and inspection.              per hour = $2,550.
----------------------------------------------------------------------------------------------------------------

    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
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                 Action                           Labor cost                  Parts cost            product per
                                                                                                       wing
----------------------------------------------------------------------------------------------------------------
Replacement of main spar cap............  80 work-hours x $85 per     $1,200 per wing...........          $8,000
                                           hour = $6,800 per wing.
----------------------------------------------------------------------------------------------------------------

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.


Sec.  39.13  [Amended]

    2. The FAA amends Sec.  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

[[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       Within the next 10    Follow Burl's
 trailing edges of both the    hours time-in-        Aircraft, LLC
 upper and lower main spar     service (TIS) after   Mandatory Service
 cap angles on both the left   the effective date    Bulletin No. 15AC06-
 and right wing for signs of   of this AD or 3       08-10, dated June
 cracks, intergranular         months after the      8, 2010; and FAA
 exfoliation, and corrosion.   effective date of     Advisory Circular
                               this AD, whichever    (AC) 43.13-1B,
                               occurs first; or if   Change 1, Chapter
                               the left and/or       6. AC 43.13-1B can
                               right wing have       be found at http://
                               been repaired and     rgl.faa.gov/.
                               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.
(2) After completing the
 inspection required in
 paragraph (f)(1) of this
 AD:
    (i) Install new           (i) Install           Follow Burl's
     inspection hole skin      inspection hole       Aircraft, LLC
     reinforcement doublers    skin reinforcement    Mandatory Service
     and the associated        doublers: Within      Bulletin No. 15AC06-
     screw cover plate in      the next 25 hours     08-10, dated June
     both the left and right   TIS after the         8, 2010; Burl's
     wing.                     effective date of     Aircraft, LLC
                               this AD or within 6   Drawing No. SB
                               months after the      15AC06-08-10 (not
                               effective date of     dated), and FAA
                               this AD, whichever    Advisory Circular
                               occurs first; or if   (AC) 43.13-1B,
                               the left and/or       Change 1, Chapter
                               right wing have       6. AC 43.13-1B can
                               been repaired and     be found at http://
                               both the upper and    rgl.faa.gov/.
                               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.
    (ii) Through the          (ii) Inspect: Before
     inspection access         further flight
     panels, inspect the       after installing
     leading and trailing      the inspection hole
     edges of both the upper   skin reinforcement
     and lower main spar cap   doublers.
     angles on both the left
     and right wing for
     signs of cracks,
     intergranular
     exfoliation and
     corrosion; and
    (iii) Remove any light    (iii) Remove
     corrosion and treat the   corrosion and treat
     entirety of both the      with corrosion
     upper and lower main      inhibitor: Before
     spar cap angles on both   further flight
     the left and right wing   after the
     with corrosion            inspection required
     inhibitor.                in paragraph
                               (f)(2)(ii) of this
                               AD.
(3) If cracks, intergranular  Before further        Follow Burl's
 exfoliation, or moderate or   flight after the      Aircraft, LLC
 severe corrosion is found     inspection required   Mandatory Service
 during the inspection         in paragraphs         Bulletin No. 15AC06-
 required in paragraphs        (f)(1) and            08-10, dated June
 (f)(1) or (f)(2)(ii) of       (f)(2)(ii) of this    8, 2010; and
 this AD, replace the          AD.                   contact Burl's
 affected main spar cap                              Aircraft, LLC in
 angles in their entirety as                         paragraph (i) of
 a single piece. Splicing of                         this AD for a
 the main spar cap angles is                         replacement scheme
 not permitted.                                      and incorporate the
                                                     replacement scheme
(4) Removing the wing         (i) Repetitively      Follow Burl's
 inspection access panels,     thereafter at         Aircraft, LLC
 repetitively inspect both     intervals not to      Mandatory Service
 the upper and lower forward   exceed every 12       Bulletin No. 15AC06-
 main spar caps on both the    months after the      08-10, dated June
 left and right wing for       inspection required   8, 2010; and FAA
 signs of cracks,              in paragraph          Advisory Circular
 intergranular exfoliation,    (f)(2)(ii) of this    (AC) 43.13-1B,
 and corrosion.                AD.                   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:

[[Page 18457]]

 
    (i) If only light         Before further        Follow Burl's
     corrosion is found,       flight after each     Aircraft, LLC
     remove the corrosion      inspection required   Mandatory Service
     and treat the main spar   in paragraph (f)(4)   Bulletin No. 15AC06-
     cap angles with           of this AD.           08-10, dated June
     corrosion inhibitor;.     Continue with the     8, 2010; and FAA
                               repetitive            Advisory Circular
                               inspections           (AC) 43.13-1B,
                               required in           Change 1, Chapter
                               paragraph (f)(4) of   6. AC 43.13-1B can
                               this AD.              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    As of the effective   Not applicable.
 cap angles that have been     date of this AD.
 inspected and are free of
 cracks, intergranular
 exfoliation, or moderate or
 severe corrosion.
------------------------------------------------------------------------

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


