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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-2142; Project Identifier AD-2024-00033-A]
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)
2020-26-16, which applies to certain Piper Aircraft, Inc. (Piper) Model
PA-28-151, PA-28-161, PA-28-181, PA-28-235, PA-28R-180, PA-28R-200, PA-
28R-201, PA-28R-201T, PA-28RT-201, PA-28RT-201T, PA-32-260, PA-32-300,
PA-32R-300, PA-32RT-300, and PA-32RT-300T airplanes. AD 2020-26-16
requires calculating the factored service hours (FSH) for each main
wing spar to determine when an inspection is required, inspecting the
lower main wing spar bolt holes for crack(s), and replacing any cracked
main wing spar. Since the FAA issued AD 2020-26-16, the FAA evaluated
the reports required by AD 2020-26-16 and determined that repetitive
inspections of the lower main wing spar bolt holes for crack(s) and
non-crack damage (including deep scratches, gouges, and thread marks)
and replacement or modification of the main wing spar should be
required, calculated service hours (CSH) should be used instead of FSH
to determine times for required actions for each main wing spar, and
that certain airplanes should be removed from the applicability and a
new airplane model added to the applicability. This proposed AD would
require calculating the CSH for each main wing spar; repetitively
inspecting the lower main wing spar bolt holes for crack(s) and non-
crack damage and taking corrective actions as needed; and replacing or
modifying main wing spars at a specified time. This proposed AD would
also revise the applicability by removing certain airplanes and adding
a new airplane model. 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 December
9, 2024 (note: in accordance with 14 CFR 11.47(c) the FAA has extended comment
period from November 7, 2024).
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 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.
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2024-2142; 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.
Material Incorporated by Reference:
For Piper material identified in this proposed AD, contact
Piper Aircraft, Inc., 2926 Piper Drive, Vero Beach, Florida 32960;
phone: (772) 567-4361; email: piper.com">customerservice@piper.com; website:
piper.com.
You may view this material 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 (817) 222-5110.
FOR FURTHER INFORMATION CONTACT: Fred Caplan, Aviation Safety Engineer,
FAA, 1701 Columbia Avenue, College Park, GA 30337; phone: (404) 474-
5507; email: 9-ASO-ATLACO-ADS@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 No. FAA-2024-2142; Project Identifier
AD-2024-00033-A" 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
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 Fred
Caplan, Aviation Safety Engineer, 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 2020-26-16, Amendment 39-21371 (86 FR 3769,
January 15, 2021) (AD 2020-26-16), for certain Piper Model PA-28-151,
PA-28-161, PA-28-181, PA-28-235, PA-28R-180, PA-28R-200, PA-28R-201,
PA-28R-201T, PA-28RT-201, PA-28RT-201T, PA-32-260, PA-32-300, PA-32R-
300, PA-32RT-300, and PA-32RT-300T airplanes. AD 2020-26-16 was prompted
by an accident involving wing separation on a Piper Model PA-28R-201 airplane. An
investigation by the National Transportation Safety Board (NTSB)
revealed a fatigue crack in a visually inaccessible area of the lower
main wing spar cap. The applicability of the NPRM for AD 2020-26-16
included additional Piper model airplanes with similar main wing spar
structures as the Model PA-28R-201. Based on airplane usage history,
the FAA determined that only those airplanes with a higher risk for
fatigue cracks (airplanes with a significant history of operation in
flight training or other high-load environments) should be subject to
the inspection requirements proposed in that NPRM.
AD 2020-26-16 requires calculating the FSH for each main wing spar
to determine when an inspection is required, inspecting the lower main
wing spar bolt holes for cracks, and replacing any cracked main wing
spar. The agency issued AD 2020-26-16 to detect and correct fatigue
cracks in the lower main wing spar cap bolt holes.
Actions Since AD 2020-26-16 Was Issued
The preamble to AD 2020-26-16 explains that the FAA considers the
requirements "interim action" and was considering further rulemaking.
The FAA has now determined that further rulemaking is necessary, and
this proposed AD follows from that determination. The FAA evaluated the
inspection reports submitted by operators as required by AD 2020-26-16
and determined that additional action is needed, including requiring
repetitive inspections of the lower main wing spar bolt holes for
crack(s) and non-crack damage and replacement or modification of the
main wing spar, using CSH instead of FSH to determine times for
required actions, and revising the applicability by removing certain
serial-numbered Piper Model PA-32-300 airplanes and all Model PA-32R-
300, PA-32RT-300, and PA-32RT-300T airplanes because those airplanes
would be included in the applicability of a proposed separate
rulemaking action. The FAA also determined that Piper Model PA-32S-300
airplanes should be added to the applicability.
Since the FAA issued AD 2020-26-16, the FAA has analyzed the
accident history of the airplanes affected by AD 2020-26-16 and other
Piper airplanes operated in a similar fashion. The following paragraphs
communicate the FAA's findings on this subject.
Accident History
Fatigue cracking was present in the main wing spars of Piper Model
PA-28-181, Model PA-28R-201, and Model PA-28-161 airplanes involved in
the following accidents. The following NTSB reports are related to this
issue and can be found on ntsb.gov.
NTSB Accident Number FTW87FA088: March 30, 1987--Marlin,
TX--Piper Model PA-28-181--7,490 hours time-in-service (TIS). This
accident was determined to have been caused by fatigue cracking in the
outboard bolt holes of the main wing spar. This airplane's primary
usage was a "Pipeline Patrol" mission.
NTSB Accident Number NYC93FA140: August 2, 1993--
Provincetown, MA--Piper Model PA-28-181--11,683 hours TIS. This
accident was determined to have been caused by structural overloading
related to weather, but fatigue cracks were present near the outboard
bolt holes. This airplane's usage history included personal use, flight
instruction, and charter flights.
NTSB Accident Number ERA18FA120: April 4, 2018--Daytona
Beach, FL--Piper Model PA-28R-201--7,691 hours TIS. This accident was
determined to have been caused by fatigue cracking in the outboard bolt
holes of the main wing spar. This airplane's primary usage was flight
instruction.
Bolt Hole Cracks and Other Findings
Following the release of AD 2020-26-16, the FAA and Piper received
over 2,800 bolt-hole eddy current inspection reports. The inspections
performed in the field revealed a mix of observations that warrant
further discussion. Of the total inspections, over 100 reported a
positive eddy current indication, with several including pictures of
the bolt hole showing the source of the indication.
Piper later conducted more detailed inspections in a study of 24
main wing spars with 20 having positive eddy current indications. Out
of the 20 positive indications, 3 were identified as fatigue cracks,
where 1 was confirmed by Piper, and 2 were confirmed by the NTSB. The
remaining were determined to be features not consistent with a crack,
and 1 overstress crack as confirmed by the NTSB.
Though not all are confirmed, many of the indications are likely
not fatigue cracks but are a variety of anomalies in the hole. These
can include corrosion pitting, scratches, gouges, and threading marks
possibly caused by forceful insertion and removal of the close-fit
bolts without proper unloading of the wing or other reasons. While
these may not present as fatigue cracks at the time of inspection,
anomalies in the hole create a stress concentration where cracks can
begin to grow. Therefore, it is still crucial to inspect the critical
bolt holes for these issues and take corrective action to prevent the
formation of fatigue cracks. Piper Service Bulletin No. 1345, Revision
A, dated September 17, 2021 (Piper SB No. 1345, Revision A); and Piper
Service Bulletin No. 1372, dated April 3, 2024 (Piper SB No. 1372),
include procedures for distinguishing between indications caused by
hole damage or other anomalies from those caused by cracks.
In addition to the various forms of non-crack hole damage, the
inspections revealed several cracks in and around the bolt holes. As
part of the AD 2020-26-16 inspection reports, 6 cracks were found,
including 2 later verified by NTSB lab examination and 1 verified by
Piper (from the Piper study referenced above), and 3 visible cracks in
photos. Other known cracks include those found in an airplane of the
same operator fleet as the 2018 accident airplane, a separately
submitted crack finding confirmed with dye penetrant, and a crack
located on the lower spar cap surface running alongside the inspection
bolt holes. Given these findings, additional cracks may be present
among the other unconfirmed reported indications.
Other cracks have been discovered that may be caused by overload
rather than by fatigue. While use of the airplane within its limits
should not cause an overload crack, some crack findings have revealed
that airplanes have been operated outside their limits. Though cracks
due to overload are not the primary source of this corrective action,
this emphasizes the need for and importance of inspecting the spar bolt
holes for evidence of any cracking.
Long-Term Continued Operational Safety
The AD 2020-26-16 inspection report results indicated that
additional inspections are needed to manage the safety of the fleet.
While AD 2020-26-16 addressed the immediate safety concern, data
indicates that more airplanes will need to be inspected and, due to
aging, the airplanes already inspected will need additional
inspections. This includes the need to expand inspections to include
Piper Model PA-32S-300 airplanes in the applicability of this proposed
AD because these airplanes share a similar structural design of the
main wing spar with the airplane models addressed in AD 2020-26-16
Crack development is a function of many factors, including the
design of the structure, how severely the aircraft is flown, and
manufacturing processes. Small imperfections may exist in any aircraft
structure from an early age; however, through operation, these
imperfections may slowly grow into fatigue cracks. Fatigue cracks have
the effect of weakening the structure and its ability to support the
stresses the aircraft was originally designed to handle.
The 2018 accident, along with other accidents in this fleet
attributed to fatigue cracking, and the AD 2020-26-16 inspection
reports, indicate an aging fleet that requires intervention to ensure
any fatigue cracking does not reach a critical state prior to being
detected. This often takes the form of repetitive inspections to be
able to capture the formation of a detectable crack, requiring repair
or replacement. The FAA has also determined that inspections alone are
not sufficient to keep the fleet risk acceptably low long-term. Cracks
are more likely to develop with aging of the main wing spar, so over
time it becomes more likely that cracks will exist throughout the fleet
and could be missed by inspection, due in part to the inherent
imperfections of the inspection method; therefore, replacement or
modification of the spars is needed. Both the FAA and Piper attempted
to determine an inspection program that would manage risk to an
acceptable level using inspection alone; however, no method could be
found that did not eventually require spar replacement.
Ensuring further damage is not caused by the inspection itself is
important, especially with repetitive inspections; however, inspecting
for fatigue cracks as well as other hole anomalies is critical and
outweighs the risk associated with repetitive inspections.
Additionally, repeated inspections inherently allow for continued
direct observation of the bolt holes over time and correcting non-crack
damage if necessary. Piper has developed service actions, most recently
in Piper SB No. 1345, Revision A, and Piper SB No. 1372, that mitigate
inspection-induced damage by emphasizing proper unloading of the wing
for both bolt and wing removal and replacement, if necessary, along
with other instructions for ensuring care of the bolt holes.
Corrective Action Development
Each requirement outlined in this proposed AD has been developed to
both address the unsafe condition and limit the number of required
inspections, reducing the burden on operators where possible. A brief
discussion of each aspect of the requirements continues below.
Airplane Model Grouping
The inspection data received via the reporting requirement in AD
2020-26-16, along with testing of the baseline spar common to all Piper
Model PA-28 and PA-32 airplanes has shown that inspections should be
extended to include all models that share a similar structural design
by utilizing the same baseline spar. It is likely that a significant
contributing factor in the formation of cracks found in the main wing
spar bolt attachment area is the cold bending of the spar to achieve
the wing's dihedral. This method of forming the spar dihedral combined
with the proximity to the wing attachment bolt holes leads to high
residual stress in that area. The potential for fatigue cracking in and
around the bolt holes, as well as higher variability in crack location
and severity, is higher under this constant additional stress.
In an attempt to support less onerous inspections and to understand
the causal factors, Piper investigated the residual stresses in the
critical bolt-hole area. That investigation showed that the residual
stress due to the spar cold bending process is a significant
contributing factor in reducing the fatigue life of the spar bolt
holes. An additional outcome of this investigation is a change to all
new manufactured spars having machined dihedral bends to eliminate the
residual stresses in the critical area.
Though there are differences between all Model PA-28 and PA-32
airplanes, such as additional reinforcing structure and lower
operational loads, all airplane models share this same baseline spar
with the cold bent dihedral. Differing characteristics allow for a
grouping and tailoring of the requirements for each airplane model, but
all airplane models need to be inspected. The current proposed
requirements separate models into two groups, each requiring its own
actions with a separate action for a third group under a separate
proposed rulemaking action. The airplane models discussed share similar
spar structure, while one group experiences higher operational loads
than the other, due mostly to differences in gross weight and maximum
airspeed. The remaining Piper Model PA-28 and PA-32 airplanes that
would not be included in the applicability of this proposed AD either
experience lower operational loads or have additional structure, both
effectively lowering the stress experienced in the subject bolt holes
of the baseline spar.
Hours Calculation
The potential for fatigue cracking of the main wing spar bolt holes
is highly influenced by the usage profile of the spar and airplane. For
airplanes included in the applicability of this proposed AD, the
primary usage is either flight instruction or personal use. Flight
instruction consists of more hours spent flying at lower altitudes
where the airplane is exposed to gusts and more takeoffs and landings
than is typical for personal usage. These characteristics lead to
reaching the fatigue life of the spar more quickly than personal usage,
which generally involves a large time spent in cruise and fewer
takeoffs and landings. As a result of the usage differences, the same
TIS for an airplane used in flight instruction is not equivalent to the
same time for a personal-use airplane.
An FSH equation was established in AD 2020-26-16 to account for the
differences in usage and reduce the burden on personal use airplanes.
This equation is still the best method available to account for
different usage when determining when inspections should occur. In the
United States, airplanes used in flight instruction for hire are
required by FAA regulation to receive 100-hour inspections. Because
instructional usage is unable to be tracked directly, a count of these
inspections is used as a method for determining instructional usage to
differentiate it from personal usage.
When AD 2020-26-16 was issued, available analysis indicated
instructional usage was approximately 17 times more severe than
personal usage, leading to this factor appearing in the FSH equation.
After AD 2020-26-16 was published, further analysis completed by Piper
estimated this factor was significantly lower. This has resulted in a
new equation, now referred to as CSH in Piper SB No. 1372. The CSH
calculation has the same instructions and intent as the FSH from AD
2020-26-16, but the value in the equation has been updated based on
improved analysis and data. For Group 1 airplanes this proposed AD
would require using a value of 3 instead of the value of 2 that is
specified in Piper SB No. 1372, and a value of 2 would be used for
Group 2 airplanes, as specified in Piper SB No. 1372.
Determination of Inspection and Spar Retirement or Modification Timing
The fleet corrective actions analyzed consist of an initial
inspection, followed by repetitive inspections until a time is
reached when the spar should be modified or replaced. The FAA has
worked with Piper to develop the specific timing for these actions
using actual service data to determine current and future risk of
fatigue cracks developing, and analysis using the physical properties
of the structure to estimate formation and growth of cracks in the
critical area of the spar. These efforts have resulted in inspection
timing estimates that provide opportunities to locate cracks before
reaching a critical size.
The proposed initial inspection time requirements for Group 1 and
Group 2 airplanes have been determined using data from AD 2020-26-16
inspection reports and prior inspections consisting of known crack
findings and known inspections that did not find an anomaly that
exceeds the eddy current size threshold, to estimate times when a crack
will exist in each group's fleet. An initial inspection time is then
set just prior to when cracks would be expected in the fleet. This
proposed initial inspection serves as a baseline inspection and will be
followed by repetitive inspections to ensure a crack is not missed.
The proposed repetitive inspection programs have been set
differently for each airplane group. For Group 1 airplanes, a tiered
approach of inspecting more often with increasing age has been proposed
as a method of reducing the burden on lower TIS airplanes. It is
possible to inspect less used airplanes less often because these carry
the least risk of developing a fatigue crack within the population. As
age increases, and therefore risk increases, the proposed inspections
are set to be more frequent. A similar approach would be possible for
Group 2 airplanes, but the inspection intervals are estimated to be
much shorter based on inspection data, structural design, and airplane
performance, so stepping down with age would not be practical.
As an airplane ages, the likelihood or risk of a crack developing
increases. A potential solution to this would be to continue to
increase the frequency of inspections to ensure a crack is found before
reaching a critical length; however, frequent and increased inspections
are not a practical or safe approach due to the inherent risk in
repeated bolt removal and reinsertion. At the fleet level, an ever-
increasing age of the fleet means a higher risk that cracks are present
in the fleet and may be missed, even with frequent inspections. This
leaves a solution of removing or modifying the highest age spars to
reduce and maintain the fleet risk, therefore spar retirement or
modification where possible is proposed.
These proposed fleet inspection requirements must be adjusted as
needed to ensure cracks are found before they reach a critical size. A
recent inspection of a Model PA-28-181 airplane main wing spar was
performed at a time earlier than required by AD 2020-26-16 and revealed
cracks at a TIS earlier than anticipated. A section of the main wing
spar was sent to an independent materials lab, and under high
magnification normally spaced fatigue striations were found, confirming
this crack was caused by fatigue. This new finding required the FAA to
adjust the Group 1 inspection schedules to earlier times to ensure a
similar crack would be found in time.
Although this airplane was used almost exclusively for flight
instruction, reducing the inspection times resulted in additional
burden on all airplanes, including those for personal usage. Therefore,
for this proposed AD, the FAA determined that for Group 1 airplanes a
value of 3 should be used in the CSH instead of the value of 2 that is
specified in Piper SB No. 1372. An increase in this value from 2 to 3
serves to mitigate the increased burden on Group 1 airplanes resulting
from the reduced inspection times and provides relief for operators of
personal-use airplanes.
Spar Modification and Replacement Options
Piper has developed a reinforcement kit as an option and
alternative to retirement of the main wing spar, applicable to certain
Group 1 airplanes. There is currently no spar modification developed
for Piper Model PA-28R-180 and PA-28R-200 airplanes that are included
in Group 1 or any airplanes designated as Group 2 airplanes, as
specified in Piper SB No. 1372. The proposed inspection times after
installing a reinforcement kit would provide an extended life of the
main wing spar and longer intervals between the proposed repetitive
inspections. The reinforcement kit provides additional structure that
lowers and distributes the stress in the critical areas, allowing for
slower crack growth. Piper used damage tolerance analysis when
developing the inspection times after a reinforcement kit is installed.
Finally, new wing spars are available from Piper that have machined
the spar dihedral bend instead of the cold bending process, eliminating
the residual stress factor in these spars. These new wing spars have a
different life limit and will not require any inspections.
Wing spars on the affected Piper airplanes could develop cracks
that, if not addressed, would result in a wing separating from the
fuselage in flight.
FAA's Determination
The FAA is issuing this NPRM after determining that the unsafe
condition described previously is likely to exist or develop on other
products of the same type design.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed Piper SB No. 1372. This material specifies
procedures for reviewing airplane maintenance records to determine the
number of 100-hour inspections completed on the airplane since new and
any record of main wing spar replacement; calculating the service
hours; doing eddy current inspections of the main wing spar bolt holes
for crack(s) and non-crack damage; repairing bolt holes with non-
cracking damage; for certain airplanes installing a main wing spar
reinforcement kit; and replacing a main wing spar.
This material is reasonably available because the interested
parties have access to it through their normal course of business or by
the means identified in ADDRESSES.
Proposed AD Requirements in This NPRM
This proposed AD would retain none of the requirements of AD 2020-
26-16. This proposed AD would revise the applicability by removing
certain serial-numbered Model PA-32-300 airplanes and all Piper Model
PA-32R-300, PA-32RT-300, and PA-32RT-300T airplanes because those
airplanes will be included in a separate proposed rulemaking action.
This proposed AD would add serial-numbered Model PA-28R-200 and PA-28R-
201 airplanes to the applicability to include all serial numbers and
would also add Piper Model PA-32S-300 airplanes to the applicability.
This proposed AD would require accomplishing the actions specified in
the material already described, except as discussed under "Differences
Between this AD and the Referenced Material." This proposed AD would
also require reporting inspection results to Piper and the FAA if any
cracks are found during any inspection.
Differences Between This Proposed AD and the Referenced Material
For Group 1 airplanes, to determine the CSH, instead of using the
value of 2 provided in the simplified formula in Part 1, paragraph 2.b
of the Instructions in Piper SB No. 1372, this proposed AD would require
using a value of 3.
In addition, for Group 1 airplanes, the compliance times for the
initial and repetitive inspections and the replacement or modification
of the main wing spars specified in paragraphs (i) and (j) of this
proposed AD are different from what is in Table 1 of Piper SB No. 1372.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 10,665 airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed AD:
Estimated Costs
|
ACTION
|
LABOR COST
|
PARTS COST
|
COST PER PRODUCT
|
COST ON U.S. OPERATORS
|
|
Review airplane maintenance records and determine CSH for each main wing spar
|
3 work-hours x $85 per hour = $255, per records review.
|
$0
|
$255, per records review
|
$2,719,575, per records review
|
The FAA estimates the following costs to do any necessary actions
that would be required based on the results of the proposed airplane
maintenance records review and CSH calculation. The agency has no way
of determining the number of airplanes that might need these actions:
On-Condition Costs
|
ACTION
|
LABOR COST
|
PARTS COST
|
COST PER PRODUCT
|
| Eddy current inspections of the left-hand (LH) and right-hand (RH) inspection areas LH and RH lower main wing spar (including access and restoring the airplane). |
1 work-hour contracted service x $600 per hour = $600 for the eddy current inspection.
4 work-hours x $85 per hour for access and restoring = $340. |
$20
|
$960 per inspection.
|
| Report inspection results to the FAA and Piper Aircraft, Inc. |
1 work-hour x $85 per hour = $85 per report. |
0
|
85 per report.
|
| Repair holes with non-crack damage |
2 work-hours x $85 per hour = $170. |
20
|
190.
|
| Replace main wing spar |
40 work-hours x $85 per hour = $3,400 per main wing spar. |
10,983
|
14,383 per main wing spar.
|
| Install modification (reinforcement) kit |
190 work-hours x $85 per hour = $16,150 per main wing spar. |
4,000
|
20,150 per wing spar.
|
Paperwork Reduction Act
A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to a penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a currently valid OMB Control Number. The OMB
Control Number for this information collection is 2120-0056. Public
reporting for this collection of information is estimated to be
approximately 1 hour per response, including the time for reviewing
instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the
collection of information. All responses to this collection of
information are mandatory. Send comments regarding this burden estimate
or any other aspect of this collection of information, including
suggestions for reducing this burden to: Information Collection
Clearance Officer, Federal Aviation Administration, 10101 Hillwood
Parkway, Fort Worth, TX 76177-1524.
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 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 that the 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
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:
a. Removing Airworthiness Directive 2020-26-16, Amendment 39-21371 (86
FR 3769, January 15, 2021); and
b. Adding the following new airworthiness directive:
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