
[Federal Register Volume 78, Number 241 (Monday, December 16, 2013)]
[Rules and Regulations]
[Pages 76040-76045]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-29679]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0724; Directorate Identifier 99-CE-013-AD; 
Amendment 39-17691; AD 99-26-19 R1]
RIN 2120-AA64


Airworthiness Directives; Piper Aircraft, Inc. Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are revising Airworthiness Directive (AD) 99-26-19 that 
applies to certain The New Piper Aircraft, Inc. Model J-2 airplanes 
equipped with wing lift struts. AD 99-26-19 required repetitively 
inspecting the wing lift struts for dents and corrosion; repetitively 
inspecting the wing lift strut forks for cracks; replacing any dented 
or corroded wing lift strut; replacing any cracked wing lift strut 
fork; and repetitively replacing the wing lift strut forks at specified 
times for certain airplanes. AD 99-26-19 also required incorporating a 
``NO STEP'' placard on the wing lift strut. Since we issued AD 99-26-
19, we were informed that paragraph (c) had been misinterpreted and 
caused confusion. This AD clarifies the intent of the language in 
paragraph (c) of AD 99-26-19 and retains all other requirements of AD 
99-26-19. We are issuing this AD to correct the unsafe condition on 
these products.

DATES: This AD is effective January 21, 2014.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of February 14, 
2000 (64 FR 72524, December 28, 1999).

ADDRESSES: For service information identified in this AD, contact Piper 
Aircraft, Inc., Customer Services, 2926 Piper Drive, Vero Beach, 
Florida 32960; telephone: (772) 567-4361; Internet: www.piper.com. You 
may review copies of the referenced service information at the FAA, 
Small Airplane Directorate, 901 Locust, Kansas City, Missouri 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 by searching for and locating it in Docket No. FAA-
2013-0724; 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 AD, the regulatory evaluation, any comments 
received, and other information. The address for the Docket Office 
(phone: 800-647-5527) is Document Management Facility, U.S. Department 
of Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Gregory ``Keith'' Noles, Aerospace 
Engineer, FAA, Atlanta Aircraft Certification Office, 1701 Columbia 
Avenue, College Park, Georgia 30337; phone: (404) 474-5551; fax: (404) 
474-5606; email: gregory.noles@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to revise AD 99-26-19, Amendment 39-11479 (64 FR 72524, 
December 28, 1999), (``AD 99-26-19''). AD 99-26-19 applied to the 
specified products. The NPRM published in the Federal Register on 
August 13, 2013 (78 FR 49221). The NPRM proposed to retain all 
requirements of AD 99-26-19

[[Page 76041]]

and clarify our intent of required actions if the seal on a sealed wing 
lift strut is ever improperly broken.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We received no comments on the NPRM or on the determination of 
the cost to the public.

Conclusion

    We reviewed the relevant data and determined that air safety and 
the public interest require adopting this AD as proposed except for 
minor editorial changes. We have determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM (78 FR 49221, August 13, 2013) for correcting the unsafe 
condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM (78 FR 49221, August 13, 2013).

Costs of Compliance

    We estimate that this AD affects 91 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD. However, 
the only difference in the costs presented below and the costs 
associated with AD 99-26-19 is the change in the labor rate from $65 
per hour to $85 per hour:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
             Action                   Labor cost          Parts cost       Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Inspection of the wing lift       8 work-hours x $85  Not applicable....  $680 per            $61,880 per
 struts and wing lift strut        per hour = $680                         inspection cycle.   inspection cycle.
 forks.                            per inspection
                                   cycle.
Installation placard............  1 work-hour x $85   $30...............  $115..............  $10,465.
                                   = $85.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary replacements 
that will be required based on the results of the inspection. We have 
no way of determining the number of aircraft that might need these 
replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                      Labor cost per wing lift strut   Parts cost per    product per
                                                                                wing lift strut  wing lift strut
----------------------------------------------------------------------------------------------------------------
Replacement of the wing lift strut and/or      4 work-hours x $85 per hour =              $440             $780
 wing lift strut forks.                         $340.
----------------------------------------------------------------------------------------------------------------

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 have determined that this AD will not have federalism 
implications under Executive Order 13132. This AD will 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 that this AD:
    (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),
    (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.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by removing Airworthiness Directive (AD) 
99-26-19, Amendment 39-11479 (64 FR 72524, December 28, 1999), and 
adding the following new AD:

99-26-19 R1 Piper Aircraft, Inc.: Amendment 39-17691; Docket No. 
FAA-2013-0724; Directorate Identifier 99-CE-013-AD.

(a) Effective Date

    This AD is effective January 21, 2014.

(b) Affected ADs

    This AD revises AD 99-26-19, Amendment 39-11479 (64 FR 72524, 
December 28, 1999). AD 99-01-05, Amendment 39-10972 (63 FR 72132, 
December 31, 1998), which superseded AD 93-10-06, Amendment 39-8586 
(58 FR 29965, May 25, 1993), also relates to the subject of this AD.

[[Page 76042]]

(c) Applicability

    This AD applies to Piper Aircraft, Inc. Model J-2 airplanes, 
serial numbers 500 through 1975, that are:
    (1) equipped with wing lift struts; and
    (2) certificated in any category.

(d) Subject

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

(e) Unsafe Condition

    (1) The subject of this AD was originally prompted by reports of 
corrosion damage found on the wing lift struts. We are revising AD 
99-26-19, Amendment 39-11479 (64 FR 72524, December 28, 1999), 
because of reports that paragraph (c) had been misinterpreted and 
caused confusion. This AD removes the language in paragraph (c) of 
AD 99-26-19, which caused the confusion.
    (2) This AD clarifies the FAA's intention that if a sealed wing 
lift strut assembly is installed as a replacement part, the 
repetitive inspection requirement is terminated only if the seal is 
never improperly broken. If the seal is improperly broken, then that 
wing lift strut becomes subject to continued repetitive inspections. 
We did not intend to promote drilling holes into or otherwise 
unsealing a sealed strut. This AD retains all the actions required 
in AD 99-26-19 and this AD does not require any actions over that 
already required in AD 99-26-19. This AD does not add any additional 
burden to the owners/operators of the affected airplanes.
    (3) We are issuing this AD to detect and correct corrosion and 
cracking on the front and rear wing lift struts and forks, which 
could cause the wing lift strut to fail. This failure could result 
in the wing separating from the airplane.

(f) Paragraph Designation Changes to AD 99-26-19

    Since AD 99-26-19, Amendment 39-11479 (64 FR 72524, December 28, 
1999), was issued, the AD format has been revised, and certain 
paragraphs have been rearranged. As a result, the corresponding 
paragraph identifiers have changed in this AD, as listed in the 
following table:

   Table 1 to Paragraph (f) of This AD--Revised Paragraph Identifiers
------------------------------------------------------------------------
                                     Corresponding  requirement  in this
     Requirement in AD 99-26-19                       AD
------------------------------------------------------------------------
             paragraph (a)                        paragraph (h)
          paragraph (a)(1)                     paragraph (i)(1)
       paragraph (a)(1)(i)                  paragraph (i)(1)(i)
      paragraph (a)(1)(ii)                 paragraph (i)(1)(ii)
          paragraph (a)(2)                     paragraph (i)(2)
       paragraph (a)(2)(i)                  paragraph (i)(2)(i)
      paragraph (a)(2)(ii)                 paragraph (i)(2)(ii)
          paragraph (a)(3)                     paragraph (j)(1)
          paragraph (a)(4)                     paragraph (j)(2)
             paragraph (b)                        paragraph (k)
paragraph (b)(1) through (b)(1)(ii)               paragraph (l)
   paragraph (b)(1)(ii)(A)                     paragraph (l)(1)
paragraph (b)(1)(ii)(B) and                    paragraph (l)(2)
                 (b)(1)(iv)
     paragraph (b)(1)(ii)(C) and               paragraph (l)(3)
                 (b)(1)(iv)
paragraph (b)(1)(iii) and (b)(2)               paragraph (m)(1)
paragraph (b)(3) through (b)(3)(ii)            paragraph (m)(2)
             Paragraph (c)                              Removed
             paragraph (d)                     paragraph (n)(1)
          paragraph (d)(1)                  paragraph (n)(1)(i)
          paragraph (d)(2)                 paragraph (n)(1)(ii)
                       N/A                     Paragraph (n)(2)
------------------------------------------------------------------------

(g) Compliance

    Unless already done (compliance with AD 99-26-19, Amendment 39-
11479 (64 FR 72524, December 28, 1999)), do the following actions 
within the compliance times specified in paragraphs (h) through (n) 
of this AD, including all subparagraphs. Properly unsealing and 
resealing a sealed wing lift strut is still considered a terminating 
action for the repetitive inspection requirements of this AD as long 
as all appropriate regulations and issues are considered, such as 
static strength, fatigue, material effects, immediate and long-term 
(internal and external) corrosion protection, resealing methods, 
etc. Current FAA regulations in 14 CFR 43.13(b) specify that 
maintenance performed will result in the part's condition to be at 
least equal to its original or properly altered condition. Any 
maintenance actions that unseal a sealed wing lift strut should be 
coordinated with the Atlanta Aircraft Certification Office (ACO) 
through the local airworthiness authority (e.g., Flight Standards 
District Office). There are provisions in paragraph (o) of this AD 
for approving such actions as an alternative method of compliance 
(AMOC).

(h) Remove Wing Lift Struts

    At whichever of the compliance times specified in paragraphs 
(h)(1) or (h)(2) of this AD that occurs later, remove the wing lift 
struts following Piper Service Bulletin (SB) No. 528D, dated October 
19, 1990. Before further flight after the removal, do the actions in 
one of the following paragraphs (i)(1), (i)(2), (j)(1), or (j)(2) of 
this AD, including all subparagraphs.
    (1) Within 1 calendar month after February 14, 2000 (the 
effective date retained from AD 99-26-19, Amendment 39-11479 (64 FR 
72524, December 28, 1999)); or
    (2) Within 24 calendar months after the last inspection done in 
accordance with AD 93-10-06, Amendment 39-8586 (58 FR 29965, May 25, 
1993).

(i) Inspect Wing Lift Struts

    Before further flight after the removal required in paragraph 
(h) of this AD, inspect each wing lift strut following paragraph 
(i)(1) or (i)(2) of this AD, including all subparagraphs, or do the 
wing lift strut replacement following one of the options in 
paragraph (j)(1) or (j)(2) of this AD.
    (1) Inspect each wing lift strut for corrosion and perceptible 
dents following Piper SB No. 528D, dated October 19, 1990.
    (i) If no corrosion is visible and no perceptible dents are 
found on any wing lift strut during the inspection required in 
paragraph (i)(1) of this AD, before further flight, apply corrosion 
inhibitor to each wing lift strut following Piper SB No. 528D, dated 
October 19, 1990. Repetitively thereafter inspect each wing lift 
strut at intervals not to exceed 24 calendar months following the 
procedures in paragraph (i)(1) or (i)(2) of this AD, including all 
subparagraphs.
    (ii) If corrosion or perceptible dents are found on any wing 
lift strut during the inspection required in paragraph (i)(1) of 
this AD or during any repetitive inspection required in paragraph 
(i)(1)(i) of this AD, before further flight, replace the affected 
wing lift strut with one of the replacement options specified in 
paragraph (j)(1) or (j)(2) of this AD. Do the replacement following 
the procedures specified in those paragraphs, as applicable.
    (2) Inspect each wing lift strut for corrosion following the 
procedures in the Appendix to this AD. This inspection must be done 
by a Level 2 or Level 3 inspector certified using the guidelines 
established by the American Society for Non-destructive Testing or 
the ``Military Standard for Nondestructive Testing Personnel 
Qualification and Certification'' (MIL-STD-410E), which can be found 
on the Internet at http://aerospacedefense.thomasnet.com/Asset/MIL-STD-410.pdf.
    (i) If no corrosion is found on any wing lift strut during the 
inspection required in paragraph (i)(2) of this AD and all 
requirements in the Appendix to this AD are met, before further 
flight, apply corrosion inhibitor to each wing lift strut following 
Piper SB No. 528D, dated October 19, 1990. Repetitively thereafter 
inspect each wing lift strut at intervals not to exceed 24 calendar 
months following the procedures in paragraph (i)(1) or (i)(2) of 
this AD, including all subparagraphs.
    (ii) If corrosion is found on any wing lift strut during the 
inspection required in paragraph (i)(2) of this AD or during any 
repetitive inspection required in paragraph (i)(2)(i) of this AD, or 
if any requirement in the Appendix of this AD is not met, before 
further flight after any inspection in which corrosion is found or 
the Appendix requirements are not met, replace the affected wing 
lift strut with one of the replacement options specified in 
paragraph (j)(1) or (j)(2) of this AD. Do the replacement following 
the procedures specified in those paragraphs, as applicable.

(j) Wing Lift Strut Replacement Options

    Before further flight after the removal required in paragraph 
(h) of this AD, replace the wing lift struts following one of the 
options in paragraph (j)(1) or (j)(2) of this AD, or inspect each 
wing lift strut following paragraph (i)(1) or (i)(2) of this AD, 
including all subparagraphs.
    (1) Install original equipment manufacturer (OEM) part number 
wing lift struts (or FAA-

[[Page 76043]]

approved equivalent part numbers) that have been inspected following 
the procedures in either paragraph (i)(1) or (i)(2) of this AD, 
including all subparagraphs, and are found to be airworthy. Do the 
installations following Piper SB No. 528D, dated October 19, 1990. 
Repetitively thereafter inspect the newly installed wing lift struts 
at intervals not to exceed 24 calendar months following the 
procedures in either paragraph (i)(1) or (i)(2) of this AD, 
including all subparagraphs.
    (2) Install new sealed wing lift strut assemblies (or FAA-
approved equivalent part numbers) (these sealed wing lift strut 
assemblies also include the wing lift strut forks) following Piper 
SB No. 528D, dated October 19, 1990. Installing one of these new 
sealed wing lift strut assemblies terminates the repetitive 
inspection requirements in paragraphs (i)(1) and (i)(2) of this AD, 
and the wing lift strut fork removal, inspection, and replacement 
requirements in paragraphs (k) and (l) of this AD, including all 
subparagraphs, for that wing lift strut assembly.

(k) Remove Wing Lift Strut Forks

    Within the next 100 hours time-in-service (TIS) after February 
14, 2000 (the effective date retained from AD 99-26-19, Amendment 
39-11479 (64 FR 72524, December 28, 1999)) or within 500 hours TIS 
after the last inspection done in accordance with AD 93-10-06, 
Amendment 39-8586 (58 FR 29965, May 25, 1993), whichever occurs 
later, remove the wing lift strut forks (unless already replaced in 
accordance with paragraph (j)(2) of this AD). Do the removal 
following Piper SB No. 528D, dated October 19, 1990. Before further 
flight after the removal, do the actions in one of the following 
paragraphs (l) or (m) of this AD, including all subparagraphs.

(l) Inspect Wing Lift Strut Forks

    Before further flight after the removal required in paragraph 
(k) of this AD, inspect the wing lift strut forks following 
paragraph (l) of this AD, including all subparagraphs, or do the 
wing lift strut fork replacement following one of the options in 
paragraph (m)(1) or (m)(2) of this AD. Inspect the wing lift strut 
forks for cracks using magnetic particle procedures, such as those 
contained in FAA Advisory Circular (AC) 43.13-1B, Chapter 5, which 
can be found in the Internet at http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/
99c827db9baac81b86256b4500596c4e/$FILE/Chapter%2005.pdf. 
Repetitively thereafter inspect at intervals not to exceed 500 hours 
TIS until the replacement time requirement specified in paragraph 
(l)(2) or (l)(3) of this AD is reached provided no cracks are found.
    (1) If cracks are found during any inspection required in 
paragraph (l) of this AD or during any repetitive inspection 
required in paragraph (l)(2) or (l)(3) of this AD, before further 
flight, replace the affected wing lift strut fork with one of the 
replacement options specified in paragraph (m)(1) or (m)(2) of this 
AD. Do the replacement following the procedures specified in those 
paragraphs, as applicable.
    (2) If no cracks are found during the initial inspection 
required in paragraph (l) of this AD and the airplane is currently 
equipped with floats or has been equipped with floats at any time 
during the previous 2,000 hours TIS since the wing lift strut forks 
were installed, at or before accumulating 1,000 hours TIS on the 
wing lift strut forks, replace the wing lift strut forks with one of 
the replacement options specified in paragraph (m)(1) or (m)(2) of 
this AD. Do the replacement following the procedures specified in 
those paragraphs, as applicable. Repetitively thereafter inspect the 
newly installed wing lift strut forks at intervals not to exceed 500 
hours TIS following the procedures specified in paragraph (l) of 
this AD, including all subparagraphs.
    (3) If no cracks are found during the initial inspection 
required in paragraph (l) of this AD and the airplane has never been 
equipped with floats during the previous 2,000 hours TIS since the 
wing lift strut forks were installed, at or before accumulating 
2,000 hours TIS on the wing lift strut forks, replace the wing lift 
strut forks with one of the replacement options specified in 
paragraph (m)(1) or (m)(2) of this AD. Do the replacement following 
the procedures specified in those paragraphs, as applicable. 
Repetitively thereafter inspect the newly installed wing lift strut 
forks at intervals not to exceed 500 hours TIS following the 
procedures specified in paragraph (l) of this AD, including all 
subparagraphs.

(m) Wing Lift Strut Fork Replacement Options

    Before further flight after the removal required in paragraph 
(k) of this AD, replace the wing lift strut forks following one of 
the options in paragraph (m)(1) or (m)(2) of this AD, or inspect the 
wing lift strut forks following paragraph (1) of this AD, including 
all subparagraphs
    (1) Install new OEM part number wing lift strut forks of the 
same part numbers of the existing part (or FAA-approved equivalent 
part numbers) that were manufactured with rolled threads. Wing lift 
strut forks manufactured with machine (cut) threads are not to be 
used. Do the installations following Piper SB No. 528D, dated 
October 19, 1990. Repetitively thereafter inspect and replace the 
newly installed wing lift strut forks at intervals not to exceed 500 
hours TIS following the procedures specified in paragraph (l) of 
this AD, including all subparagraphs.
    (2) Install new sealed wing lift strut assemblies (or FAA-
approved equivalent part numbers) (these sealed wing lift strut 
assemblies also include the wing lift strut forks) following Piper 
SB No. 528D, dated October 19, 1990. This installation may have 
already been done through the option specified in paragraph (j)(2) 
of this AD. Installing one of these new sealed wing lift strut 
assemblies terminates the repetitive inspection requirements in 
paragraphs (i)(1) and (i)(2) of this AD, and the wing lift strut 
fork removal, inspection, and replacement requirements in paragraphs 
(k) and (l) of this AD, including all subparagraphs, for that wing 
lift strut assembly.

(n) Install Placard

    (1) Within 1 calendar month after February 14, 2000 (the 
effective date retained from AD 99-26-19, Amendment 39-11479 (64 FR 
72524, December 28, 1999), or within 24 calendar months after the 
last inspection required by AD 93-10-06, Amendment 39-8586 (58 FR 
29965, May 25, 1993), whichever occurs later, and before further 
flight after any replacement of a wing lift strut assembly required 
by this AD, do the actions in one of the following paragraphs 
(n)(1)(i) or (n)(1)(ii) of this AD:
    (i) Install ``NO STEP'' decal, Piper (P/N) 80944-02, on each 
wing lift strut approximately 6 inches from the bottom of the wing 
lift strut in a way that the letters can be read when entering and 
exiting the airplane; or
    (ii) Paint the words ``NO STEP'' approximately 6 inches from the 
bottom of the wing lift strut in a way that the letters can be read 
when entering and exiting the airplane. Use a minimum of 1-inch 
letters using a color that contrasts with the color of the airplane.
    (2) The ``NO STEP'' markings required by paragraph (n)(1)(i) and 
(n)(1)(ii) of this AD must remain in place for the life of the 
airplane.

(o) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Atlanta 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.
    (3) AMOCs approved for AD 93-10-06, Amendment 39-8586 (58 FR 
29965, May 25, 1993) and AD 99-26-19, Amendment 39-11479 (64 FR 
72524, December 28, 1999) are approved as AMOCs for this AD.

(p) Related Information

    For more information about this AD, contact Gregory K. Noles, 
Aerospace Engineer, FAA, Atlanta ACO, 1701 Columbia Avenue, College 
Park, Georgia 30337; phone: (404) 474-5551; fax: (404) 474-5606; 
email: gregory.noles@faa.gov.

(q) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (3) The following service information was approved for IBR on 
February 14, 2000 (64 FR 72524, December 28, 1999).
    (i) Piper Service Bulletin No. 528D, dated October 19, 1990.
    (ii) Reserved.
    (4) For Piper Aircraft, Inc. service information identified in 
this AD, contact Piper Aircraft, Inc., Customer Services, 2926

[[Page 76044]]

Piper Drive, Vero Beach, Florida 32960; telephone: (772) 567-4361; 
Internet: www.piper.com.
    (5) You may view this service information at FAA, Small Airplane 
Directorate, 901 Locust, Kansas City, Missouri 64106. For 
information on the availability of this material at the FAA, call 
(816) 329-4148.
    (6) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

Appendix to AD 99-26-19 R1

Procedures and Requirements for Ultrasonic Inspection of Piper Wing 
Lift Struts

EQUIPMENT REQUIREMENTS

    1. A portable ultrasonic thickness gauge or flaw detector with 
echo-to-echo digital thickness readout capable of reading to 0.001-
inch and an A-trace waveform display will be needed to do this 
inspection.
    2. An ultrasonic probe with the following specifications will be 
needed to do this inspection: 10 MHz (or higher), 0.283-inch (or 
smaller) diameter dual element or delay line transducer designed for 
thickness gauging. The transducer and ultrasonic system shall be 
capable of accurately measuring the thickness of AISI 4340 steel 
down to 0.020-inch. An accuracy of +/- 0.002-inch throughout a 
0.020-inch to 0.050-inch thickness range while calibrating shall be 
the criteria for acceptance.
    3. Either a precision machined step wedge made of 4340 steel (or 
similar steel with equivalent sound velocity) or at least three shim 
samples of same material will be needed to do this inspection. One 
thickness of the step wedge or shim shall be less than or equal to 
0.020-inch, one shall be greater than or equal to 0.050-inch, and at 
least one other step or shim shall be between these two values.
    4. Glycerin, light oil, or similar non-water based ultrasonic 
couplants are recommended in the setup and inspection procedures. 
Water-based couplants, containing appropriate corrosion inhibitors, 
may be utilized, provided they are removed from both the reference 
standards and the test item after the inspection procedure is 
completed and adequate corrosion prevention steps are then taken to 
protect these items.
     NOTE: Couplant is defined as ``a substance used between 
the face of the transducer and test surface to improve transmission 
of ultrasonic energy across the transducer/strut interface.''
     NOTE: If surface roughness due to paint loss or 
corrosion is present, the surface should be sanded or polished 
smooth before testing to assure a consistent and smooth surface for 
making contact with the transducer. Care shall be taken to remove a 
minimal amount of structural material. Paint repairs may be 
necessary after the inspection to prevent further corrosion damage 
from occurring. Removal of surface irregularities will enhance the 
accuracy of the inspection technique.

INSTRUMENT SETUP

    1. Set up the ultrasonic equipment for thickness measurements as 
specified in the instrument's user's manual. Because of the variety 
of equipment available to perform ultrasonic thickness measurements, 
some modification to this general setup procedure may be necessary. 
However, the tolerance requirement of step 13 and the record keeping 
requirement of step 14, must be satisfied.
    2. If battery power will be employed, check to see that the 
battery has been properly charged. The testing will take 
approximately two hours. Screen brightness and contrast should be 
set to match environmental conditions.
    3. Verify that the instrument is set for the type of transducer 
being used, i.e. single or dual element, and that the frequency 
setting is compatible with the transducer.
    4. If a removable delay line is used, remove it and place a drop 
of couplant between the transducer face and the delay line to assure 
good transmission of ultrasonic energy. Reassemble the delay line 
transducer and continue.
    5. Program a velocity of 0.231-inch/microsecond into the 
ultrasonic unit unless an alternative instrument calibration 
procedure is used to set the sound velocity.
    6. Obtain a step wedge or steel shims per item 3 of the 
EQUIPMENT REQUIREMENTS. Place the probe on the thickest sample using 
couplant. Rotate the transducer slightly back and forth to ``ring'' 
the transducer to the sample. Adjust the delay and range settings to 
arrive at an A-trace signal display with the first backwall echo 
from the steel near the left side of the screen and the second 
backwall echo near the right of the screen. Note that when a single 
element transducer is used, the initial pulse and the delay line/
steel interface will be off of the screen to the left. Adjust the 
gain to place the amplitude of the first backwall signal at 
approximately 80% screen height on the A-trace.
    7. ``Ring'' the transducer on the thinnest step or shim using 
couplant. Select positive half-wave rectified, negative half-wave 
rectified, or filtered signal display to obtain the cleanest signal. 
Adjust the pulse voltage, pulse width, and damping to obtain the 
best signal resolution. These settings can vary from one transducer 
to another and are also user dependent.
    8. Enable the thickness gate, and adjust the gate so that it 
starts at the first backwall echo and ends at the second backwall 
echo. (Measuring between the first and second backwall echoes will 
produce a measurement of the steel thickness that is not affected by 
the paint layer on the strut). If instability of the gate trigger 
occurs, adjust the gain, gate level, and/or damping to stabilize the 
thickness reading.
    9. Check the digital display reading and if it does not agree 
with the known thickness of the thinnest thickness, follow your 
instrument's calibration recommendations to produce the correct 
thickness reading. When a single element transducer is used this 
will usually involve adjusting the fine delay setting.
    10. Place the transducer on the thickest step of shim using 
couplant. Adjust the thickness gate width so that the gate is 
triggered by the second backwall reflection of the thick section. If 
the digital display does not agree with the thickest thickness, 
follow your instruments calibration recommendations to produce the 
correct thickness reading. A slight adjustment in the velocity may 
be necessary to get both the thinnest and the thickest reading 
correct. Document the changed velocity value.
    11. Place couplant on an area of the lift strut which is thought 
to be free of corrosion and ``ring'' the transducer to surface. 
Minor adjustments to the signal and gate settings may be required to 
account for coupling improvements resulting from the paint layer. 
The thickness gate level should be set just high enough so as not to 
be triggered by irrelevant signal noise. An area on the upper 
surface of the lift strut above the inspection area would be a good 
location to complete this step and should produce a thickness 
reading between 0.034-inch and 0.041-inch.
    12. Repeat steps 8, 9, 10, and 11 until both thick and thin shim 
measurements are within tolerance and the lift strut measurement is 
reasonable and steady.
    13. Verify that the thickness value shown in the digital display 
is within +/- 0.002-inch of the correct value for each of the three 
or more steps of the setup wedge or shims. Make no further 
adjustments to the instrument settings.
    14. Record the ultrasonic versus actual thickness of all wedge 
steps or steel shims available as a record of setup.

INSPECTION PROCEDURE

    1. Clean the lower 18 inches of the wing lift struts using a 
cleaner that will remove all dirt and grease. Dirt and grease will 
adversely affect the accuracy of the inspection technique. Light 
sanding or polishing may also be required to reduce surface 
roughness as noted in the EQUIPMENT REQUIREMENTS section.
    2. Using a flexible ruler, draw a \1/4\-inch grid on the surface 
of the first 11 inches from the lower end of the strut as shown in 
Piper SB No. 528D, dated October 19, 1990, or Piper SB No. 910A, 
dated October 10, 1989. This can be done using a soft (2) 
pencil and should be done on both faces of the strut. As an 
alternative to drawing a complete grid, make two rows of marks 
spaced every \1/4\-inch across the width of the strut. One row of 
marks should be about 11 inches from the lower end of the strut, and 
the second row should be several inches away where the strut starts 
to narrow. Lay the flexible ruler between respective tick marks of 
the two rows and use tape or a rubber band to keep the ruler in 
place. See Figure 1.
    3. Apply a generous amount of couplant inside each of the square 
areas or along the edge of the ruler. Re-application of couplant may 
be necessary.
    4. Place the transducer inside the first square area of the 
drawn grid or at the first \1/4\-inch mark on the ruler and ``ring'' 
the transducer to the strut. When using a dual element transducer, 
be very careful to record the thickness value with the axis of the 
transducer elements perpendicular to any curvature in the strut. If 
this is not done, loss of signal or inaccurate readings can result.

[[Page 76045]]

    5. Take readings inside each square on the grid or at \1/4\-inch 
increments along the ruler and record the results. When taking a 
thickness reading, rotate the transducer slightly back and forth and 
experiment with the angle of contact to produce the lowest thickness 
reading possible. Pay close attention to the A-scan display to 
assure that the thickness gate is triggering off of maximized 
backwall echoes.
     NOTE: A reading shall not exceed .041 inch. If a 
reading exceeds .041-inch, repeat steps 13 and 14 of the INSTRUMENT 
SETUP section before proceeding further.
    6. If the A-trace is unsteady or the thickness reading is 
clearly wrong, adjust the signal gain and/or gate setting to obtain 
reasonable and steady readings. If any instrument setting is 
adjusted, repeat steps 13 and 14 of the INSTRUMENT SETUP section 
before proceeding further.
    7. In areas where obstructions are present, take a data point as 
close to the correct area as possible.
     NOTE: The strut wall contains a fabrication bead at 
approximately 40% of the strut chord. The bead may interfere with 
accurate measurements in that specific location.
    8. A measurement of 0.024-inch or less shall require replacement 
of the strut prior to further flight.
    9. If at any time during testing an area is encountered where a 
valid thickness measurement cannot be obtained due to a loss of 
signal strength or quality, the area shall be considered suspect. 
These areas may have a remaining wall thickness of less than 0.020-
inch, which is below the range of this setup, or they may have small 
areas of localized corrosion or pitting present. The latter case 
will result in a reduction in signal strength due to the sound being 
scattered from the rough surface and may result in a signal that 
includes echoes from the pits as well as the backwall. The suspect 
area(s) shall be tested with a Maule ``Fabric Tester'' as specified 
in Piper SB No. 528D, dated October 19, 1990, or Piper SB No. 910A, 
dated October 10, 1989.
    10. Record the lift strut inspection in the aircraft log book.
    [GRAPHIC] [TIFF OMITTED] TR16DE13.001
    


    Issued in Kansas City, Missouri, on November 22, 2013.
Earl Lawrence,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2013-29679 Filed 12-13-13; 8:45 am]
BILLING CODE 4910-13-P


