[Federal Register Volume 86, Number 177 (Thursday, September 16, 2021)]
[Proposed Rules]
[Pages 51636-51639]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-19959]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-1006; Project Identifier 2019-CE-047-AD]
RIN 2120-AA64


Airworthiness Directives; Piper Aircraft, Inc. Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD) 78-
02-03, which applies to all Piper Aircraft, Inc. (Piper), Model PA-23-
250 airplanes. AD 78-02-03 requires repetitively inspecting the 
stabilator tip tube and weight assemblies for cracks, inspecting for 
missing rivets and screws, replacing the forward rib/horn assemblies, 
and reinforcing the mounting. Since AD 78-02-03 was issued, Piper 
developed a newly-designed stabilator, which is not subject to the 
unsafe condition, and revised its service information. This proposed AD 
would retain the actions of AD 78-02-03, but would reduce the 
applicability and require the actions in the revised service 
information. The FAA is proposing this AD to address the unsafe 
condition on these products.

DATES: The FAA must receive comments on this proposed AD by November 1, 
2021.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to https://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 NPRM, contact Piper 
Aircraft, Inc., 2926 Piper Drive, Vero Beach, FL 32960; phone: (772) 
299-2141; website: https://www.piper.com/. You may view this service 
information at the FAA, Airworthiness Products Section, Operational 
Safety Branch, 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 at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2020-1006; or in person at 
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The AD docket contains this NPRM, any comments 
received, and other information. The street address for Docket 
Operations is listed above.

FOR FURTHER INFORMATION CONTACT: John Marshall, Aviation Safety 
Engineer, Atlanta ACO Branch, FAA, 1701 Columbia Avenue, College Park, 
GA 30337; phone: (404) 474-5524; fax: (404) 474-5605; email: 
john.r.marshall@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under ADDRESSES. Include ``Docket Number FAA-2020-1006; Project

[[Page 51637]]

Identifier 2019-CE-047-AD'' at the beginning of your comments. The most 
helpful comments reference a specific portion of the proposal, explain 
the reason for any recommended change, and include supporting data. The 
FAA will consider all comments received by the closing date and may 
amend the proposal because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
https://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this NPRM.

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this NPRM contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this NPRM, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this NPRM. Submissions containing CBI should be sent to John 
Marshall, Aviation Safety Engineer, Atlanta ACO Branch, FAA, 1701 
Columbia Avenue, College Park, GA 30337. Any commentary that the FAA 
receives which is not specifically designated as CBI will be placed in 
the public docket for this rulemaking.

Background

    The FAA issued AD 78-02-03 [Reg. Docket No. 77-EA-81, Amendment 39-
3128] (43 FR 3079, January 23, 1978) (AD 78-02-03), for all Piper Model 
PA-23-250 airplanes. AD 78-02-03 was prompted by cracks found on the 
stabilator structure during routine inspections, including cracks in 
the tip balance weight, abnormal trim tab horn bushing wear, and skin 
and nose rib cracks. The FAA issued AD 78-02-03 to prevent weakening of 
the stabilator structure and loss of the trim tab and counter balance 
weight, which could result in reduced airplane control.
    For all Model PA-23-250 airplanes, AD 78-02-03 requires 
repetitively inspecting both the stabilator tip tube and the weight 
assemblies for cracks, with follow-on alterations or replacements as 
necessary, in accordance with Piper Service Bulletin (SB) No. 540, 
dated January 4, 1977 (Piper SB 540). For different groups of serial-
numbered airplanes, AD 78-02-03 requires a one-time inspection of the 
stabilator tip ribs for missing rivets and missing tube and weight 
assembly attachment screws with alteration as necessary, replacement of 
the right and left stabilator tab forward inboard rib/horn assemblies, 
and/or reinforcement of the mounting of the stabilator tube and weight 
assemblies. The repetitive inspections in AD 78-02-03 for all serial-
numbered airplanes have no terminating action and are required 
regardless of any corrective actions performed.

Actions Since AD 78-02-03 Was Issued

    Since the FAA issued AD 78-02-03, Piper changed the design of the 
stabilator structure. Airplanes beginning with serial number 27-7954122 
were manufactured with the stabilator design change and are not subject 
to the unsafe condition addressed by AD 78-02-03. The FAA determined 
the applicability of AD 78-02-03 should be revised to exclude those 
later-manufactured airplanes.
    In addition, Piper revised SB 540, the service bulletin required by 
AD 78-02-03 for the repetitive inspections of the stabilator tip tube 
and the weight assemblies. Piper SB 540B, dated February 9, 2021 (Piper 
SB 540B), reduces the applicability of the affected serial numbers and 
contains separate instructions for inspecting and repairing airplanes 
with a modified tube and weight assembly or with a stabilizer balance 
weight replacement kit part number (P/N) 763 987.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed the following service documents proposed for 
compliance with this NPRM:
     Piper SB No. 547, dated March 1, 1977, which contains 
instructions for inspecting the stabilator tip rib;
     Piper SB No. 569, dated August 24, 1977, which contains 
information for replacing the stabilator tab horn;
     Piper Service Letter No. 807A, dated September 8, 1977, 
which contains information for installing the stabilator outboard nose 
rib; and
     Piper SB No. 540B, February 9, 2021, which contains 
instructions for inspecting the stabilator tip tube and weight assembly 
and addressing any cracks found.
    This service information is reasonably available because the 
interested parties have access to it through their normal course of 
business or by the means identified in the ADDRESSES.

Other Related Service Information

    The FAA reviewed the following documents for information related to 
this NPRM:
     Piper SB 540, which contains instructions for inspecting 
and reinforcing the stabilator tip tube and weight assembly; and
     Piper Aztec Service Manual, Part Number 753-564, dated 
January 1, 2009. Paragraphs 4-65 through 4-67 of this manual contain 
procedures for checking control surface balance.

FAA's Determination

    The FAA is issuing this NPRM after determining the unsafe condition 
described previously is likely to exist or develop in other products of 
the same type design.

Proposed AD Requirements in This NPRM

    This proposed AD would retain all of the requirements of AD 78-02-
03 but would reduce the applicability and update some of the service 
information that would be required for compliance.

Differences Between This Proposed AD and the Service Information

    Piper SB 540B specifies contacting Piper for repair instructions. 
This proposed AD would require contacting the FAA for an approved 
repair method instead.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 625 airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this proposed 
AD:

[[Page 51638]]



                                                 Estimated Costs
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                                                                                                 Cost on U.S.
             Action                   Labor cost          Parts cost       Cost per product        operators
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Inspect the stabilator tip tube   0.5 work-hour x     Not applicable....  $42.50 per          $26,562.50 per
 and weight assembly.              $85 per hour =                          inspection cycle.   inspection cycle.
                                   $42.50.
Inspect the stabilator tip ribs.  0.5 work-hour x     Not applicable....  $42.50............  $26,562.50.
                                   $85 per hour =
                                   $42.50.
Replace the stabilator tab        4 work-hours x $85  $817..............  $1,157............  $723,125.
 forward rib/horn assemblies.      per hour = $340.
Install additional nose ribs....  1 work-hour x $85   $367..............  $452..............  $282,500.
                                   per hour = $85.
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    The FAA estimates the following costs to do any necessary repairs 
or replacements that would be required based on the results of the 
proposed inspection. The FAA has no way of determining the number of 
airplanes that might need these repairs or replacements:

                                               On-Condition Costs
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                                                                                                     Cost per
                 Action                           Labor cost                  Parts cost              product
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Repair stabilator tip tube and weight     4 work-hours x $85 per      $80.......................            $420
 assemblies (airplanes without kit P/N     hour = $340.
 763 987).
Install missing stabilator tip rib        1 work hour x $85 per hour  39........................             124
 rivets and/or the stabilator tip tube     = $85.
 and weight assembly attachment screws.
Balance stabilator......................  5 work-hours x $85 per      Not applicable............             425
                                           hour = $425.
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    For airplanes with kit P/N 763 987, the cost to repair cracking may 
vary significantly from airplane to airplane, and therefore the FAA has 
no way of determining an estimated cost.

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.
    The FAA is 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

    The FAA has 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) Would not affect intrastate aviation in Alaska, and
    (3) Would 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

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:
0
a. Removing Airworthiness Directive 78-02-03 [Reg. Docket No. 77-EA-81, 
Amendment 39-3128] (43 FR 3079, January 23, 1978); and
0
b. Adding the following new airworthiness directive:

Piper Aircraft, Inc.: Docket No. FAA-2020-1006; Project Identifier 
2019-CE-047-AD.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by November 1, 2021.

(b) Affected ADs

    This AD replaces AD 78-02-03 [Reg. Docket No. 77-EA-81, 
Amendment 39-3128] (43 FR 3079, January 23, 1978) (AD 78-02-03).

(c) Applicability

    This AD applies to Piper Aircraft, Inc., Model PA-23-250 
airplanes, serial numbers 27-7654001 through 27-7954121, 
certificated in any category.

(d) Subject

    Joint Aircraft System Component (JASC) Code 5510, Horizontal 
Stabilizer Structure.

(e) Unsafe Condition

    This AD was prompted by reports of cracks developing on the 
stabilator structure. The FAA is issuing this AD to prevent 
weakening of the stabilator structure and to detect and correct 
cracks on the stabilator tip tube and

[[Page 51639]]

weight assembly. The unsafe condition, if not addressed, could cause 
weakening of the complete structure and lead to loss of the trim tab 
and counter balance weight, which may result in reduced airplane 
control.

(f) Compliance

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

(g) Previously Required Actions Retained From AD 78-02-03

    (1) Within 50 hours time-in-service (TIS) after January 26, 1978 
(the effective date of AD 78-02-03), do the following inspections 
and modifications.
    (i) For airplanes with serial numbers 27-7654001 through 27-
7754054, inspect both stabilator tip ribs for missing rivets and 
missing tube and weight assembly attachment screws and if necessary 
alter in accordance with Piper Service Bulletin (SB) 547, dated 
March 1, 1977.
    (ii) For airplanes with serial numbers 27-7654001 through 27-
7754127, 27-7754130, 27-7754131, 27-7754133 through 27-7754136, and 
27-7754138 through 27-7754144, replace the right and left stabilator 
tab forward inboard rib/horn assemblies by installing Piper Kit 761 
143 or equivalent kit in accordance with Piper SB 569, dated August 
24, 1977.
    (iii) For airplanes with serial numbers 27-7654001 through 27-
7754041 equipped with stabilators Piper part number (P/N) 15658-2, 
15658-3, 15658-22 or 15658-23, reinforce the mounting of the 
stabilator tube and weight assemblies by installing additional nose-
ribs with Piper Kit 761 141 or equivalent kit in accordance with 
Piper Service Letter 807A, dated September 8, 1977.
    (2) Before further flight after completing the alterations in 
paragraphs (g)(1)(ii) and (iii) of this AD, balance the stabilator.

(h) Inspection of Stabilator Tip Tube and Weight Assembly

    Within 10 hours TIS after the effective date of this AD or 
within 100 hours TIS after completing the last inspection required 
by paragraph (a) of AD 78-02-03, whichever occurs later, and 
thereafter at intervals not to exceed 100 hours TIS, inspect the 
left and right stabilator balance weight assemblies for cracks and 
complete any necessary repairs by following Parts I and II of the 
Instructions in Piper SB No. 540B, dated February 9, 2021, except 
you are not required to contact Piper for repair instructions. 
Instead, repair in accordance with FAA-approved procedures.

(i) Credit for Previous Actions

    You may take credit for the initial inspection and corrective 
actions required by paragraph (h) of this AD if you performed those 
actions before the effective date of this AD using Piper SB No. 540, 
dated January 4, 1977, or SB No. 540A, dated October 20, 1980.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Atlanta ACO Branch, 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 certification office, send it to the attention of the 
person identified in Related Information.
    (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) For service information that contains steps that are labeled 
as Required for Compliance (RC), the following provisions apply.
    (i) The steps labeled as RC, including substeps under an RC step 
and any figures identified in an RC step, must be done to comply 
with the AD. An AMOC is required for any deviations to RC steps, 
including substeps and identified figures.
    (ii) Steps not labeled as RC may be deviated from using accepted 
methods in accordance with the operator's maintenance or inspection 
program without obtaining approval of an AMOC, provided the RC 
steps, including substeps and identified figures, can still be done 
as specified, and the airplane can be put back in an airworthy 
condition.

(k) Related Information

    (1) For more information about this AD, contact John Marshall, 
Aviation Safety Engineer, Atlanta ACO Branch, FAA, 1701 Columbia 
Avenue, College Park, GA 30337; phone: (404) 474-5524; fax: (404) 
474-5605; email: john.r.marshall@faa.gov.
    (2) For service information identified in this AD, contact Piper 
Aircraft, Inc., 2926 Piper Drive, Vero Beach, FL 32960; phone: (772) 
299-2141; website: https://www.piper.com/. You may view this 
referenced service information at the FAA, Airworthiness Products 
Section, Operational Safety Branch, 901 Locust, Kansas City, MO 
64106. For information on the availability of this material at the 
FAA, call (816) 329-4148.

    Issued on September 9, 2021.
Ross Landes,
Deputy Director for Regulatory Operations, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-19959 Filed 9-15-21; 8:45 am]
BILLING CODE 4910-13-P


