[Federal Register Volume 76, Number 86 (Wednesday, May 4, 2011)]
[Proposed Rules]
[Pages 25264-25273]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-10818]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0450; Directorate Identifier 2011-CE-010-AD]
RIN 2120-AA64


Airworthiness Directives; Cessna Aircraft Company (Cessna) Models 
337, 337A (USAF 02B), 337B, 337C, 337D, 337E, T337E, 337F, T337F, 337G, 
T337G, M337B, F 337E, FT337E, F 337F, FT337F, F 337G, and FT337GP 
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 inspecting the 
wings for internal and external damage, repairing any damage, 
reinforcing the wings, installing operational limitation placards in 
the cockpit, and adding limitations to the airplane flight manual 
supplement. This proposed AD was prompted by a review of installed 
Flint Aero, Inc. wing tip auxiliary fuel tanks, Supplemental Type 
Certificate (STC) SA5090NM. We are issuing this proposed AD to detect 
and correct damage in the wings and to prevent overload failure of the 
wing due to the installation of the STC. Damage in the wing or overload 
failure of the wing could result in structural failure of the wing, 
which could result in loss of control.

DATES: We must receive comments on this proposed AD by June 20, 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 
Flint Aero, Inc., 1942 Joe Crosson Drive, El Cajon, CA 92020; phone: 
(619) 448-1551; fax: (619) 448-1571; Internet: http://www.flintaero.com. You may review copies of the referenced service 
information at the FAA, Small Airplane Directorate, 901 Locust, 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://

[[Page 25265]]

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: Dara Albouyeh, Aerospace Engineer, 
FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Blvd., 
Lakewood, CA 90712; phone: (562) 627-5222; fax: (562) 627-5210; e-mail: 
[email protected].

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-2011-0450; 
Directorate Identifier 2011-CE-010-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.

Discussion

    In May 2010, we reviewed wing tip auxiliary fuel tank extension 
STCs to Cessna 336 and 337 series airplanes for compliance with 
airworthiness standards. Due to the STC similarities between Aviation 
Enterprises wing tip auxiliary fuel tank extensions and Flint Aero, 
Inc. wing tip auxiliary fuel tank extensions, both were reviewed for 
possible wing overload conditions.
    In June 2010, we determined the proper design loads for both 
Aviation Enterprises wing tip auxiliary fuel tank extension and Flint 
Aero, Inc. wing tip auxiliary fuel tank extension STCs exceeded the 
strength capabilities of the outer portions of the wing.
    On October 4, 2010, we issued AD 2010-21-18, Amendment 39-16478 (75 
FR 64111, October 19, 2010), which applies to Cessna Models 336, 337, 
337A (USAF 02B), 337B, M337B (USAF 02A), T337B, 337C, T337C, 337D, 
T337D, 337E, T337E, 337F, T337F, 337G, T337G, 337H, P337H, T337H, 
T337H-SP, F337E, FT337E, F337F, FT337F, F337G, FT337GP, F337H, and 
FT337HP airplanes that are now or have ever been modified by Aviation 
Enterprises wing tip auxiliary fuel tank extensions Supplemental Type 
Certificates (STC) SA02055AT, SA02056AT, SA02307AT, or SA02308AT.
    In January 2011, Flint Aero, Inc. confirmed the under-strength 
condition of the outer wing section.
    This condition, if not corrected, could result in structural 
failure of the wing, which could result in loss of control.

Relevant Service Information

    We reviewed Flint Aero, Inc. Service Bulletin FA2, Rev 2, dated 
April 8, 2011, and Flint Aero, Inc. Drawing FA2, Rev A, dated April 8, 
2011. The service information describes procedures for the 
reinforcement of the upper wing skin, the wing front spar cap, and the 
stringers.

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 inspecting the wings for internal 
and external damage, repairing any damage, reinforcing the wings, 
installing operational limitation placards in the cockpit, and adding 
limitations to the Flint Aero, Inc. Airplane Flight Manual Supplement.

Costs of Compliance

    We estimate that this AD affects 33 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:


                                                 Estimated Costs
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                                                                                                 Cost on U.S.
             Action                   Labor cost          Parts cost       Cost per product        operators
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Inspection of the wing for       5 work-hours x $85   Not applicable....  $425 per            $14,025 per
 damage.                          per hour = $425                          inspection cycle.   inspection cycle.
                                  per inspection
                                  cycle.
Fabricating and installing       1 work-hour x $85    Not applicable....  $85...............  $2,805.
 placards in the cockpit.         per hour = $85.
Modifying the Limitations        .5 work-hour x $85   Not applicable....  $42.50............  $1,402.50.
 section of the Flint Aero,       per hour = $42.50.
 Inc. Airplane Flight Manual
 Supplement.
Reinforcing the upper wing       25 work-hours x $85  $1,070............  $3,195............  $105,435.
 skin, stringer, and wing front   per hour = $2,125.
 spar cap.
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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.

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    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):

Cessna Aircraft Company: Docket No. FAA-2011-0450; Directorate 
Identifier 2011-CE-010-AD.

Comments Due Date

    (a) We must receive comments by June 20, 2011.

Affected ADs

    (b) AD 2010-21-18, Amendment 39-16478, is related to the subject 
of this AD.

Applicability

    (c) This AD applies to Cessna Aircraft Company (Cessna) Models 
337, 337A (USAF 02B), 337B, 337C, 337D, 337E, T337E, 337F, T337F, 
337G, T337G, M337B, F 337E, FT337E, F 337F, FT337F, F 337G, and 
FT337GP airplanes, all serial numbers, that:
    (1) Are certificated in any category; and
    (2) Are or have ever been modified by Flint Aero, Inc. 
Supplemental Type Certificate (STC) SA5090NM.

Subject

    (d) Joint Aircraft System Component (JASC)/Air Transport 
Association (ATA) of America Code 57; Wings.

Unsafe Condition

    (e) This AD was prompted by a review of installed Flint Aero, 
Inc. wing tip auxiliary fuel tanks, STC SA5090NM. We are issuing 
this AD to detect and correct damage in the wings and to prevent 
overload failure of the wing due to the installation of the STC. 
Damage in the wing or overload failure of the wing could result in 
structural failure of the wing, which could result in loss of 
control.

Compliance

    (f) Comply with this AD within the compliance times specified, 
unless already done.

Required Actions

    (g) Within the next 50 hours time-in-service (TIS) after the 
effective date of this AD or within 30 days after the effective date 
of this AD, whichever occurs first, do a general and focused 
inspection of the left and right wing for internal and external 
damage at wing stations (WSTA) 150 and 177. Do the inspections 
following Appendix 1 of this AD.
    (h) After the inspection required in paragraph (g) of this AD if 
no damage was found and before the modification required in 
paragraph (k) of this AD is incorporated, anytime severe and/or 
extreme turbulence is encountered during flight, before the next 
flight do a focused inspection of the wing for damage following 
steps 1, 2, 3, 4, 7, and 10 in Appendix 1 of this AD. Also inspect 
for signs of distress in the upper front spar in the area around 
WSTA 150 and 177. The definition of severe and extreme turbulence 
can be found in table 7-1-9 of the FAA Aeronautical Information 
Manual (AIM). You may obtain a copy of the FAA AIM at http://www.faa.gov/air_traffic/publications/atpubs/aim/.
    (i) For airplanes that have not had the modification specified 
in paragraphs (j) and (k) incorporated, within the next 50 hours 
time-in-service (TIS) after the effective date of this AD or within 
30 days after the effective date of this AD, fabricate a placard 
(using at least \1/8\-inch letters) with the following words and 
install the placard on the instrument panel within the pilot's clear 
view:
    (1) ``MAINTAIN AT LEAST 12 GAL OF FUEL IN EACH WING TIP FUEL 
TANK FOR AIRPLANE WEIGHTS BETWEEN 3,400 LBS AND 4,330 LBS.''
    (2) ``MAINTAIN FULL FUEL IN EACH WING TIP FUEL TANK FOR AIRPLANE 
WEIGHTS AT OR ABOVE 4,330 LBS.''
    (j) If damage or signs of distress are found during the 
inspections required in paragraphs (g) and (h) of this AD, before 
further flight do the following:
    (1) Repair all damaged and distressed parts following FAA 
Advisory Circular (AC) 43.13-1B, Chapter 4, which can be found at 
http://rgl.faa.gov/;
    (2) Incorporate the modification reinforcement specified in 
Flint Aero, Inc. Service Bulletin FA2, Rev 2, dated April 8, 2011, 
following Flint Aero, Inc. Drawing FA2, Rev A, dated April 8, 2011;
    (3) Remove the placard specified in paragraph (i) of this AD;
    (4) Fabricate a new placard (using at least \1/8\-inch letters) 
with the following words and install the placard on the instrument 
panel within the pilot's clear view: ``MAINTAIN AT LEAST 12 GAL OF 
FUEL IN EACH WING TIP FUEL TANK FOR AIRPLANE WEIGHTS AT OR ABOVE 
4,330 LBS''; and
    (5) Incorporate the information from Appendix 2 of this AD into 
the Limitations section of the Flint Aero, Inc. Airplane Flight 
Manual Supplement.
    (k) If no damage or signs of distress are found during the 
inspections required in paragraphs (g) and (h) of this AD, within 
the next 100 hours TIS after the effective date of this AD or within 
12 months after the effective date of this AD, whichever occurs 
first, do the following:
    (1) Incorporate the modification reinforcement specified in 
Flint Aero, Inc. Service Bulletin FA2, Rev 2, dated April 8, 2011, 
following Flint Aero, Inc. Drawing FA2, Rev A, dated April 8, 2011;
    (2) Remove the placard specified in paragraph (i) of this AD;
    (3) Fabricate a new placard (using at least \1/8\-inch letters) 
with the following words and install the placard on the instrument 
panel within the pilot's clear view: ``MAINTAIN AT LEAST 12 GAL OF 
FUEL IN EACH WING TIP FUEL TANK FOR AIRPLANE WEIGHTS AT OR ABOVE 
4,330 LBS''; and
    (4) Incorporate the information from Appendix 2 of this AD into 
the Limitations section of the Flint Aero, Inc. Airplane Flight 
Manual Supplement.
    (l) You may incorporate the modification reinforcement specified 
in Flint Aero, Inc. Service Bulletin FA2, Rev 2, dated April 8, 
2011, following Flint Aero, Inc. Drawing FA2, Rev A, dated April 8, 
2011, at any time after the inspection required in paragraph (g) of 
this AD but no later than the compliance time specified in paragraph 
(k) of this AD as long as no cracks were found. As required in 
paragraph (j) of this AD, the modification reinforcement must be 
incorporated before further flight if damage or signs of distress 
are found.

Alternative Methods of Compliance (AMOCs)

    (m)(1) The Manager, Los Angeles 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

    (n) For more information about this AD, contact Dara Albouyeh, 
Aerospace Engineer, FAA, Los Angeles ACO, 3960 Paramount Blvd., 
Lakewood, CA 90712; phone: (562) 627-5222; fax: (562) 627-5210; e-
mail: [email protected].
    (o) For service information identified in this AD, contact Flint 
Aero, Inc., 1942 Joe Crosson Drive, El Cajon, CA 92020; phone: (619) 
448-1551; fax: (619) 448-1571; Internet: http://www.flintaero.com. 
You may review copies of the referenced service information at the 
FAA, Small Airplane Directorate, 901 Locust, Kansas City, MO 64106. 
For information on the availability of this material at the FAA, 
call (816) 329-4148.

[[Page 25267]]

Appendix 1 to Docket No. FAA-2011-0450

General and Focused Inspection Procedures

    Perform a general and focused inspection of the wing for 
internal and external damage from wing station (WSTA) 23 to the wing 
tip. The general inspection must be performed in accordance with 14 
CFR 43.15(c), using a checklist that includes at least the scope and 
detail of the items contained in Appendix D of 14 CFR part 43. The 
focused inspection must include the items listed below. Remove all 
wing access panels to conduct the inspections. Do these inspections 
following the manufacturer's service information and any other 
appropriate guidance, such as FAA Advisory Circular (AC) 43.13-1B 
Acceptable Methods, Techniques, and Practices--Aircraft Inspection 
and Repair. AC 43.13-1B can be found at http://rgl.faa.gov/.
    Focused inspection items to look for:
    (1) Wrinkles in upper wing skins, from the outboard edge on the 
fuel tank access covers (WSTA 150 or 177) to the WSTA 222 (See View 
B, Figure 3).
    (2) Wrinkles in the upper wing skins from WSTA 55 to 66, 
adjacent to the booms (See View E, Figure 6).
    (3) Cracking of the upper wing skins. Pay particular attention 
to any wrinkles, the radius between stiffeners at WSTA 150 (under 
fuel tank covers), and unreinforced access holes (See View B, Figure 
3).
    (4) Working (smoking) rivets outboard of the wing tank access 
covers.
    (5) Fasteners with less than two diameters edge distance.
    (6) Fasteners with less than four diameters center to center 
spacing.
    (7) Looseness of attachments of the tip extension to the wing 
and wing tip to wing extension when pushing up and down on the tip.
    (8) Any signs of distress along both front and rear spars, 
particularly in the area around WSTA 177.
    (9) Inspect under any repairs to the upper skins, particularly 
in the area just outboard of the fuel tank access covers as these 
may be covering up existing damage.
    (10) Inter-rivet buckling of the stringers attached to the upper 
surface skin, outboard of the fuel tank access covers (See View F, 
Figure 7).
    (11) Inspect rib at WSTA 222 for damage. Trimming of the rib may 
have been done to allow installation of fuel lines (See View A, 
Figure 2). Repair in accordance with AC 43.13-1B, Chapter 4, 
paragraph 4-58(g) and Figure 4-14, or by using another FAA-approved 
method that restores equivalent strength of the wing rib.

Appendix 1 to Docket No. FAA-2011-0450

General and Focused Inspection Procedures (Continued)

    (12) Inspect and identify screws, installed in tapped (threaded) 
holes in metal substructure, used to attach wing tips, stall fences, 
fuel and electrical components, and access doors. For tapped holes, 
remove fastener and open up the diameter to provide a smooth bore 
hole, for the smallest oversize fastener, using close tolerance 
holes noted in AC 43.13-1B, paragraph 7-39 or other FAA-approved 
scheme. Maintain minimum 2 x fastener diameter edge distance and 4 x 
fastener diameter center to center spacing. Select and install new, 
equivalent strength or stronger, fasteners with nuts/collars in 
accordance with AC 43.13-1B, Chapter 7 and AC 43.13-2B, paragraph 
108 or other FAA-approved repair. New fasteners must not have 
threads in bearing against the sides of the holes.
    (13) Inspect wing skins for unreinforced cutouts. (See View C, 
Figure 4).
    (14) Inspect the upper spar cap horizontal flanges for open 
holes (See View D, Figure 5).

Appendix 1 to Docket No. FAA-2011-0450 (Continued)

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Appendix 2 to Docket No. FAA-2011-0450

    Airworthiness Limitations for the Flint Aero, Inc. Airplane 
Flight Manual Supplement
    ``MAINTAIN AT LEAST 12 GAL OF FUEL IN EACH WING TIP FUEL TANK 
FOR AIRPLANE WEIGHTS AT OR ABOVE 4,330 LBS.''

    Issued in Kansas City, Missouri, on April 27, 2011.
John Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-10818 Filed 5-3-11; 8:45 am]
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