[Federal Register: February 9, 2005 (Volume 70, Number 26)]
[Proposed Rules]
[Page 6786-6792]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09fe05-13]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2004-19961; Directorate Identifier 2004-CE-48-AD]
RIN 2120-AA64
Airworthiness Directives; Air Tractor, Inc. Models AT-502, AT-
502A, AT-502B, and AT-503A 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)
2002-26-05, which applies to certain Air Tractor, Inc. (Air Tractor)
Models AT-502, AT-502A, AT-502B, and AT-503A airplanes. AD 2002-26-05
lowers the safe life for the wing lower spar cap for Models AT-502, AT-
502A, AT-502B, and AT-503A airplanes and those that incorporate or have
incorporated Marburger Enterprises, Inc. winglets. AD 2002-26-05 also
requires you to eddy-current inspect the wing lower spar cap
immediately prior to the replacement/modification to detect and correct
any crack in a bolthole before it extends to the modified center
section of the wing and report the results of this inspection to the
Federal Aviation Administration (FAA). Since we issued AD 2002-26-05,
we have determined that additional airplanes should be added to the
applicability section. We also developed an alternative method of
compliance (AMOC) to the requirements of AD 2002-26-05. This proposed
AD retains the action required in AD 2002-26-05, adds additional
airplanes to the applicability, and includes an AMOC. We are issuing
this proposed AD to prevent fatigue cracks from occurring in the wing
lower spar cap before the established safe life is reached. Fatigue
cracks in the wing lower spar cap could result in the wing separating
from the airplane during flight.
DATES: We must receive any comments on this proposed AD by April 5,
2005.
ADDRESSES: Use one of the following to submit comments on this proposed
AD:
DOT Docket Web site: Go to http://dms.dot.gov and follow
the instructions for sending your comments electronically.
Government-wide rulemaking Web site: Go to http://www.regulations.gov
and follow the instructions for sending your
comments electronically.
Mail: Docket Management Facility; U.S. Department of
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401,
Washington, DC 20590-001.
Fax: 1-202-493-2251.
Hand Delivery: Room PL-401 on the plaza level of the
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
To get the service information identified in this proposed AD,
contact Air Tractor, Incorporated, P.O. Box 485, Olney, Texas 76374; or
Marburger Enterprises, Inc., 1227 Hillcourt, Williston, North Dakota
58801; telephone: (800) 893-1420 or (701) 774-0230; facsimile: (701)
572-2602.
To view the comments to this proposed AD, go to http://dms.dot.gov.
The docket number is FAA-2004-19961.
FOR FURTHER INFORMATION CONTACT: Direct all questions to:
--For the airplanes that do not incorporate and never have incorporated
Marburger Enterprises, Inc. winglets: Rob Romero, Aerospace Engineer,
FAA, Fort Worth Airplane Certification Office, 2601 Meacham Boulevard,
Fort Worth, Texas 76193-0150; telephone: (817) 222-5102; facsimile:
(817) 222-5960; and
--For airplanes that incorporate or have incorporated Marburger
Enterprises, Inc. winglets: John Cecil, Aerospace Engineer, Los Angeles
Aircraft Certification Office, FAA, 3960 Paramount Boulevard, Lakewood,
California 90712; telephone: (562)
627-5228; facsimile: (562) 627-5210.
SUPPLEMENTARY INFORMATION:
Comments Invited
How do I comment on this proposed AD? We invite you to submit any
written relevant data, views, or arguments regarding this proposal.
Send your comments to an address listed under ADDRESSES. Include the
docket number, ``FAA-2004-19961; Directorate Identifier 2004-CE-48-AD''
at the beginning of your comments. We will post all comments we
receive, without change, to http://dms.dot.gov, including any personal
information you provide. We will also post a report summarizing each
substantive verbal contact with FAA personnel concerning this proposed
rulemaking. Using the search function of our docket web site, anyone
can find and read the comments received into any of our dockets,
including the name of the individual who sent the comment (or signed
the comment on behalf of an association, business, labor union, etc.).
This is docket number FAA-2004-19961. You may review the DOT's complete
Privacy Act Statement in the Federal Register published on April 11,
2000 (65 FR 19477-78) or you may visit http://dms.dot.gov.
Are there any specific portions of this proposed AD I should pay
attention to? We specifically invite comments on the overall
regulatory, economic, environmental, and energy aspects of this
proposed AD. If you contact us through a nonwritten communication and
that contact relates to a substantive part of this proposed AD, we will
summarize the contact and place the summary in the docket. We will
consider all comments received by the closing date and may amend this
proposed AD in light of those comments and contacts.
[[Page 6787]]
Docket Information
Where can I go to view the docket information? You may view the AD
docket that contains the proposal, any comments received, and any final
disposition in person at the DMS Docket Offices between 9 a.m. and 5
p.m. (eastern standard time), Monday through Friday, except Federal
holidays. The Docket Office (telephone 1-800-647-5227) is located on
the plaza level of the Department of Transportation NASSIF Building at
the street address stated in ADDRESSES. You may also view the AD docket
on the Internet at http: //dms.dot.gov. The comments will be available
in the AD docket shortly after the DMS receives them.
Discussion
Has FAA taken any action to this point? On January 2, 2003, we
issued AD 2002-26-05, Amendment 39-12991 (6 FR 18), which applies to
certain Air Tractor Models AT-502, AT-502A, AT-502B, and AT-503A
airplanes. AD 2002-26-05 supersedes AD 2002-11-03.
Reports of several cracks originating in the outboard \3/8\-inch
hole of the main spar lower cap on Air Tractor Models AT-502, AT-502A,
and AT-502B airplanes at hours time-in-service (TIS) lower than the
established safe life caused us to issue AD 2002-11-03, Amendment 39-
12764 (67 FR 38371, June 4, 2002).
We issued AD 2002-11-03 to lower the safe life for the wing lower
spar cap established in AD 2001-10-04 R1 on Air Tractor Models AT-502,
AT-502A, AT-502B, and AT-503A airplanes and further reduce the safe
life for airplanes that incorporate or have incorporated Marburger
Enterprises, Inc. winglets.
Additional field inspections revealed wings with cracks below the
safe life limits established in AD 2002-11-03 for Air Tractor Models AT
502, AT-502B, and AT-503A airplanes. This caused us to issue AD 2002-
26-05.
In addition, the applicability section of AD 2002-11-03 covered
only Models AT-502A and AT-502B serial number airplanes that were
already manufactured. The applicability did not account for airplanes
manufactured after the issuance of the AD.
AD 2002-26-05 currently requires the following on certain Air
Tractor Models AT-502, AT-502A, AT-502B, and AT-503A airplanes:
--maintaining the original requirements from AD 2002-11-03 for a
lowered safe life, inspection, replacement/modification, and reporting
the results to FAA;
--further lowering the safe life for the wing lower spar cap
established in AD 2001-11-03 for Models AT-502, AT-502B, and AT-503A
airplanes; and
--expanding the applicability of Models AT-502A and AT-502B airplanes
to account for future manufactured airplanes.
You must do these actions in accordance with Snow Engineering
Service Letter 197 or 205, both Revised March 26,
2001, as applicable.
What has happened since AD 2002-26-05 to initiate this proposed AD
action? Since we issued AD 2002-26-05, FAA has identified additional
airplanes that need to be added to the applicability. We have also
developed an alternative method of compliance (AMOC) to the actions of
AD 2002-26-05.
What is the potential impact if FAA took no action? If not detected
and corrected, fatigue cracks in the wing lower spar cap could cause
the wing to separate from the airplane during flight.
FAA's Determination and Requirements of This Proposed AD
What has FAA decided? We have evaluated all pertinent information
and identified an unsafe condition that is likely to exist or develop
on other products of this same type design. For this reason, we are
proposing AD action.
What would this proposed AD require? This proposed AD would
supersede AD 2002-26-05 with a new AD that would retain the actions
required in AD 2002-26-05, add additional airplanes to the
applicability, and incorporate an AMOC to the actions required by AD
2002-26-05.
How does the revision to 14 CFR part 39 affect this proposed AD? On
July 10, 2002, we published a new version of 14 CFR part 39 (67 FR
47997, July 22, 2002), which governs FAA's AD system. This regulation
now includes material that relates to altered products, special flight
permits, and alternative methods of compliance. This material
previously was included in each individual AD. Since this material is
included in 14 CFR part 39, we will not include it in future AD
actions.
Costs of Compliance
How many airplanes would this proposed AD impact? We estimate that
this proposed AD affects approximately 350 airplanes in the U.S.
registry.
What would be the cost impact of this proposed AD on owners/
operators of the affected airplanes? We estimate the following costs to
do this proposed inspection:
----------------------------------------------------------------------------------------------------------------
Total cost per
Labor cost Parts cost airplane Total cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
2 workhours x $65 per hour = No parts required $130 $130 x 350 = $45,500.
$130. for inspection.
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We estimate the following costs to do the proposed replacement/
modification:
----------------------------------------------------------------------------------------------------------------
Labor cost Parts cost Total cost per airplane
----------------------------------------------------------------------------------------------------------------
120 workhours x $65 per hour = Approximately $3,700......... $7,800 + $3,700 = $11,500
$7,800..
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What is the difference between the cost impact of this proposed AD
and the cost impact of AD 2002-26-05? The only difference is the change
in the applicability to add later-manufactured airplanes to the
proposed AD. There is no difference in cost to do the actions required
by this proposed AD.
Authority for This Rulemaking
What authority does FAA have for issuing this rulemaking action?
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.
[[Page 6788]]
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 AD.
Regulatory Findings
Would this proposed AD impact various entities? We have 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.
Would this proposed AD involve a significant rule or regulatory
action? For the reasons discussed above, I certify that this proposed
AD:
1. Is not a ``significant regulatory action'' under Executive Order
12866;
2. Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979); and
3. 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.
We prepared a summary of the costs to comply with this proposed AD
and placed it in the AD Docket. You may get a copy of this summary by
sending a request to us at the address listed under ADDRESSES. Include
``AD Docket No. 2004-CE-48-AD'' in your request.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the Federal Aviation Administration 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. FAA amends Sec. 39.13 by removing Airworthiness Directive (AD)
2002-26-05, Amendment 39-12991 (68 FR 18, January 2, 2003), and by
adding a new AD to read as follows:
Air Tractor, Inc.: Docket No. FAA-2004-19961; Directorate Identifier
2004-CE-48-AD.
When Is the Last Date I Can Submit Comments on This Proposed AD?
(a) We must receive comments on this proposed airworthiness
directive (AD) by April 5, 2005.
What Other ADs Are Affected By This Action?
(b) This AD supersedes AD 2002-26-05, Amendment 39-12991.
What Airplanes Are Affected by This AD?
(b) This AD applies to certain Models AT-502, AT-502A, AT-502B,
and AT-503A airplanes. Use paragraph (c)(1) of this AD for airplanes
that do not incorporate and never have incorporated winglets. Use
paragraph (c)(4) of this AD for certain AT-500 series airplanes that
incorporate or have incorporated Marburger Enterprises, Inc.
winglets.
(1) The following presents airplanes (certificated in any
category) that are affected by this AD, along with the new safe life
(presented in hours time-in-service (TIS)) of the wing lower spar
cap for all affected airplane models and serial numbers:
----------------------------------------------------------------------------------------------------------------
Model Serial numbers Safe Life
----------------------------------------------------------------------------------------------------------------
AT-502................................ all serial numbers beginning with 1,650 hours TIS.
502-0003.
AT-502A............................... all serial numbers beginning with 1,650 hours TIS.
502A-0158.
AT-502B............................... 502B-0187 through 502B-0654, 1,650 hours TIS.
except 502B-0643.
AT-502B............................... 502B-0643 and all serial numbers 2,100 hours TIS.
beginning with 502B-0655.
AT-503A............................... all serial numbers beginning with 1,650 hours TIS.
503A-0067.
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(2) If piston powered aircraft have been converted to turbine
power, you must use the limits for the corresponding serial number
turbine-powered aircraft.
(3) Aircraft that have been modified to install lower spar caps,
either part number 21026-1/-2, 21078-1/-2, or 21094-1/-2, should use
the limits for Model AT-502B airplanes, serial number 0643 and all
serial numbers beginning with 0655.
(4) The following presents airplanes (certificated in any
category) that could incorporate or could have incorporated
Marburger Enterprises, Inc. winglets. These winglets are installed
in accordance with Supplemental Type Certificate (STC) SA00490LA.
Use the winglet usage factor in the table below, the safe life
specified in paragraph (a)(1) of this AD, and the instructions
included in the Appendix to this AD to determine the new safe life
of these airplanes:
------------------------------------------------------------------------
Winglet
Model Serial numbers usage
factor
------------------------------------------------------------------------
AT-502.......................... 502-0003 through 502-0236.. 1.6
AT-502A......................... 502A-0158 through 502A-0238 1.6
AT-502A......................... all serial numbers 1.2
beginning with 502-0239.
AT-502B......................... all serial numbers 1.2
beginning with 502B-0187.
------------------------------------------------------------------------
What Is the Unsafe Condition Presented in This AD?
(d) The actions specified by this AD are intended to prevent
fatigue cracks from occurring in the wing lower spar cap before the
established safe life is reached. Fatigue cracks in the wing lower
spar cap, if not detected and corrected, could result in the wing
separating from the airplane during flight.
What Must I Do To Address This Problem?
(e) To address this problem, you must do the following unless
you do the alternative method of compliance (AMOC) in Appendix 2 of
this AD:
[[Page 6789]]
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Actions Compliance Procedures
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(1) Modify the applicable For airplanes The owner/operator
aircraft records (logbook) previously affected holding at least a
as follows to show the by AD 2002-26-05: private pilot
reduced safe life for the Do the logbook certificate as
wing lower spar cap (use entry within the authorized by
the information from next 10 hours TIS section 43.7 of the
paragraphs (c)(1) and after January 15, Federal Aviation
(c)(4) of this AD and 2003 (the effective Regulations (14 CFR
Appendix 1 to this AD, as date of AD 2002-26- 43.7) may modify
applicable): 05). For airplanes the aircraft
(i) Incorporate the not previously records as
following into the Aircraft affected by AD 2002- specified in
Logbook ``In accordance 26-05: Do the paragraphs
with AD **-**-** (or AD logbook entry (e)(1)(i) and
2002-26-05, as applicable): within the next 10 (e)(1)(ii) of this
the wing lower spar cap is hours TIS after AD. Make an entry
life limited to --------.'' effective date of into the aircraft
Insert the applicable safe this AD. records showing
life number from the compliance with
applicable tables in this portion of the
paragraphs (c)(1) and AD in accordance
(c)(4) of this AD and with section 43.9
Appendix 1 to this AD.. of the Federal
(ii) If, as of the time of Aviation
the logbook entry Regulations (14 CFR
requirement of paragraph 43.9). Do the
(e)(1)(i) of this AD, your actual replacement/
airplane is over or within modification
50 hours of the safe life, following the
an additional 50 hours TIS applicable Snow
is allowed to do the Engineering Service
replacement/modification.. Letter 197
or 205,
both revised March
26, 2001, or
following the
applicable sheet of
Snow Engineering
Modification--Wing
Center- splice--
502, Drawing Number
20989. The owner/
operator may not do
the replacement/
modification,
unless he/she holds
the proper mechanic
authorization.
-----------------------------
(2) You may eddy-current Inspection schedule Procedures included
inspect the wing lower spar included as part of as part of the AMOC
cap instead of doing the the AMOC in in Appendix 2 to
replacement/modification. Appendix 2 to this this AD.
The inspection schedule and AD.
procedures are included in
Appendix 2 to this AD.
-----------------------------
(3) Eddy-current inspect the Immediately before Following the
wing lower spar cap in the replacement/ applicable Snow
order to detect any crack modification Engineering Service
before it extends to the required when you Letter 197
modified center section of reach the new safe or 205,
the wing and repair any life. For airplanes both revised March
crack or replace the wing that had this 26, 2001, or
section. The inspection replacement/ following Snow
must be done by one of the modification done Engineering Process
following: following either AD Specification
(i) A Level 2 or Level 3 2001-10-04 or AD Number 197, revised
inspector that is certified 2001-10-04 R1: do June 4, 2002.
for eddy-current inspection this inspection and
using the guidelines any necessary
established by the American corrective action
Society for Nondestructive within the next 400
Testing or MIL-STD-410; or. hours TIS after
(ii) A person authorized to June 14, 2002 (the
do AD work who has effective date of
completed and passed the AD 2002-11-03),
Air Tractor, Inc. training unless already done
course on Eddy Current (have the mechanic
Inspection on wing lower who did the work
spar caps.. mark the logbooks
accordingly).
-----------------------------
(4) Report to FAA any cracks Send the report If cracks are found,
detected as the result of within 10 days send the form
each inspection required by after the (Figure 1 of this
paragraph (e)(3) of this AD inspection required AD) to FAA, Fort
on the form in Figure 1 of in paragraph (e)(3) Worth Airplane
this AD. The Office of of this AD only if Certification
Management and Budget (OMB) cracks are found. Office, Attn: Rob
approved the information Romero, 2601
collection requirements Meacham Boulevard,
contained in this Fort Worth, Texas
regulation under the 76193-0150;
provisions of the Paperwork telephone: (817)
Reduction Act of 1980 (44 222-5102;
U.S.C. 3501 et seq.) and facsimile: (817)
assigned OMB Control Number 222-5960.
2120-0056.
------------------------------------------------------------------------
Note: Upon completion of the replacement/modification required
by this AD, the safe life of the new/modified wing spar is limited
to the applicable hours listed in paragraph (c)(1) of this AD. This
new life limit starts at the time of the replacement/modification.
BILLING CODE 4910-13-P
[[Page 6790]]
[GRAPHIC] [TIFF OMITTED] TP09FE05.013
BILLING CODE 4910-13-C
[[Page 6791]]
May I Request a Different Alternative Method of Compliance?
(f) You may request a different method of compliance or a
different compliance time for this AD by following the procedures in
14 CFR 39.19.
(1) Unless FAA authorizes otherwise, send your request to your
principal inspector. The principal inspector may add comments and
will send your request to the Manager, Fort Worth or Los Angeles
Airplane Certification Office (ACO), FAA. For information on any
already approved alternative methods of compliance, contact:
(2) For the airplanes that do not incorporate and never have
incorporated Marburger Enterprises, Inc. winglets: Rob Romero,
Aerospace Engineer, FAA, Fort Worth Airplane Certification Office,
2601 Meacham Boulevard, Fort Worth, Texas 76193-0150; telephone:
(817) 222-5102; facsimile: (817) 222-5960.
(3) For airplanes that incorporate or have incorporated
Marburger Enterprises, Inc. winglets: John Cecil, Aerospace
Engineer, Los Angeles Aircraft Certification Office, FAA, 3960
Paramount Boulevard, Lakewood, California 90712; telephone: (562)
627-5228; facsimile: (562) 627-5210.
(4) Alternative methods of compliance approved in accordance
with AD 2002-26-05, which is superseded by this AD, are approved as
alternative methods of compliance with this AD.
May I Get Copies of the Documents Referenced in This AD?
(g) To get copies of the documents referenced in this AD,
contact Air Tractor, Incorporated, P.O. Box 485, Olney, Texas 76374;
or Marburger Enterprises, Inc., 1227 Hillcourt, Williston, North
Dakota 58801. To view the AD docket, go to the Docket Management
Facility; U.S. Department of Transportation, 400 Seventh Street,
S.W., Nassif Building, Room PL-401, Washington, DC, or on the
Internet at http://dms.dot.gov. The docket number is FAA-2004-19961.
Appendix 1 to Docket No. FAA-2004-19961 (as Retained From AD 2002-26-
05)
The following provides procedures for determining the safe life
for Models AT-502, AT-502A, and AT-502B airplanes that incorporate
or have incorporated Marburger Enterprises, Inc. winglets. These
winglets are installed in accordance with Supplemental Type
Certificate (STC) SA00490LA.
What if I removed the Marburger winglets prior to further flight
after the effective date of this AD or prior to the effective date
of this AD?
1. Review your airplane's logbook to determine your airplane's
time-in-service (TIS) with winglets installed per Marburger
Enterprises STC SA00490LA. This includes all time spent with the
winglets currently installed and any previous installations where
the winglet was installed and later removed.
Example: A review of your airplane's logbook shows that you have
accumulated 350 hours TIS since incorporating the Marburger STC.
Further review of the airplane's logbook shows that a previous owner
had installed the STC and later removed the winglets after
accumulating 150 hours TIS. Therefore, your airplane's TIS with the
winglets installed is 500 hours.
If you determine that the winglet STC has never been
incorporated on your airplane, then your safe life is presented in
paragraph (c)(1) of this AD. Any future winglet installation will be
subject to a reduced safe life per these instructions.
2. Determine your airplane's unmodified safe life from paragraph
(c)(1) of this AD.
Example: Your airplane is a Model AT-502B, serial number 0292. From
paragraph (c)(1) of this AD, the safe life of your airplane is 1,650
hours TIS.
All examples from hereon will be based on the Model AT-502B, serial
number 0292 airplane.
3. Determine the winglet usage factor from paragraph (c)(4) of
this AD.
Example: Again, your airplane is a Model AT-502B, serial number
0292. From paragraph (c)(4) of this AD, your winglet usage factor is
1.2.
4. Adjust the winglet TIS to account for the winglet usage
factor. Multiply the winglet TIS (result of Step 1 above) by the
winglet usage factor (result of Step 3 above).
Example: Winglet TIS is 500 hours x a winglet usage factor of 1.2.
The adjusted winglet TIS is 600 hours.
5. Calculate the winglet usage penalty. Subtract the winglet TIS
(result of Step 1 above) from the adjusted winglet TIS (result of
Step 4 above).
Example:
Adjusted winglet TIS-the winglet TIS = winglet usage penalty.
(600 hours)-(500 hours TIS) = (100 hours TIS).
6. Adjust the safe life of your airplane to account for winglet
usage. Subtract the winglet usage penalty (result of Step 5 above)
result from the unmodified safe life from paragraph (c)(1) of this
AD (result of Step 2 above).
Example:
Unmodified safe life-winglet usage penalty = adjusted safe life.
(1,650 hours TIS)-(100 hours TIS) = (1,550 hours TIS).
7. If you remove the winglets from your airplane prior to
further flight or no longer have the winglets installed on your
airplane, the safe life of your airplane is the adjusted safe life
(result of Step 6 above). Enter this number in paragraph (e)(1)(i)
of this AD and the airplane logbook.
What if I have the Marburger winglet installed as of the
effective date of this AD and plan to operate my airplane without
removing the winglet?
1. Review your airplane's logbook to determine your airplane's
TIS without the winglets installed.
Example: A review of your airplane's logbook shows that you have
accumulated 1,500 hours TIS, including 500 hours with the Marburger
winglets installed. Therefore, your airplane's TIS without the
winglets installed is 1,000 hours.
2. Determine your airplane's unmodified safe life from paragraph
(c)(1) of this AD.
Example: Your airplane is a Model AT-502B, serial number 0292. From
paragraph (c)(1) of this AD, the safe life of your airplane is 1,650
hours TIS.
All examples from hereon will be based on the Model AT-502B, serial
number 0292 airplane.
3. Determine the winglet usage factor from paragraph (c)(4) of
this AD.
Example: Again, your airplane is a Model AT-502B, serial number
0292. From paragraph (c)(4) of this AD, your winglet usage factor is
1.2.
4. Determine the potential winglet TIS. Subtract the TIS without
the winglets installed (result of Step 1 above) from the unmodified
safe life (result of Step 2 above).
Example:
Unmodified safe life-TIS without winglets = Potential winglet
TIS.
(1,650 hours TIS)-(1,000 hours TIS) = (650 hours TIS).
5. Adjust the potential winglet TIS to account for the winglet
usage factor. Divide the potential winglet TIS (result of Step 4
above) by the winglet usage factor (result of Step 3 above).
Example:
Potential winglet TIS / Winglet usage factor = Adjusted
potential winglet TIS.
(650 hours TIS) / (1.2) = (542 hours TIS).
6. Calculate the winglet usage penalty. Subtract the adjusted
potential winglet TIS (result of Step 5 above) from the potential
winglet TIS (result of Step 4 above).
Example:
Potential winglet TIS-Adjusted potential winglet TIS = Winglet
usage penalty.
(650 hours TIS)-(542 hours TIS) = (108 hours TIS).
7. Adjust the safe life of your airplane to account for the
winglet installation. Subtract the winglet usage penalty (result of
Step 6 above) from the unmodified safe life from paragraph (c)(1) of
this AD (result of Step 2 above).
Example:
Unmodified safe life - Winglet usage penalty = Adjusted safe
life.
(1,650 hours TIS) - (108 hours TIS) = (1,542 hours TIS).
8. Enter the adjusted safe life (result of Step 7 above) in
paragraph (e)(1)(i) of this AD and the airplane logbook.
What if I install or remove the Marburger winglet from my
airplane in the future?
If, at anytime in the future, you install or remove the
Marburger winglet STC from your airplane, you must repeat the
procedures in this Appendix to determine the airplane's safe life.
Appendix 2--Alternative Method Of Compliance (AMOC) to Docket No. FAA-
2004-19961
Optional Inspection Program
For all airplanes listed in this AD; except for Model AT-502B
airplanes, serial number 0643 and all serial numbers beginning with
0655; you may begin a repetitive inspection interval program as an
alternative to the safe
[[Page 6792]]
life requirement of this AD with the following provisions:
1. Upon accumulating 1,600 hours time-in-service (TIS), inspect
the outboard two lower spar cap bolt holes following Snow
Engineering Process Specification PS 197, dated June 4, 2002.
2. Repeat these inspections at intervals of (as applicable):
a. 800 hours TIS (all serial numbers except as noted in b).
b. 600 hours TIS (serial numbers AT502B-0187 through AT502B-0618
that do not have the part number 20998-1/-2 web plate installed).
c. If the outboard two lower spar cap bolt holes have been cold
worked following Snow Engineering Service Letter 233 or
234, both dated May 18, 2004, then you may double (1,600
hours TIS or 1,200 hours TIS, as applicable) the inspection interval
(See Note 1--re: mid cycle cold work).
3. If at any time a crack is found, and:
a. If the crack indication goes away by drilling the hole to the
next larger size, then you may modify your center splice following
Snow Engineering Drawing 20989. After modification, proceed to step
5.
b. If the crack indication does not go away, then you must
replace your lower spar caps before further flight.
4. For all serial numbers, upon accumulating 4,000 hours TIS,
you must modify your center splice connection following ATI drawing
20989, unless previously done. Prior to the modification perform an
eddy-current inspection following PS 197 (See Note 2).
5. Upon accumulating 1,600 hours TIS after modification, inspect
the outboard two lower spar cap bolt holes following Snow
Engineering Process Specification PS 197.
6. Repeat the inspection at intervals of:
a. 800 hours TIS; or
b. 1,600 hours TIS if the outboard two lower spar cap bolt holes
have been cold worked following Snow Engineering Service Letter
233 or 234, both dated May 18, 2004 (See Note 1).
c. If at any time a crack is found, you must replace before
further flight your lower spar caps, splice blocks, and wing attach
angles and hardware.
7. Upon accumulating 8,000 hours TIS, you must replace before
further flight your lower spar caps, splice blocks, and wing attach
angles (P/N 20693-1) and associated hardware.
Note 1: If you decide to cold work your bolt holes following
Snow Engineering Service Letter 233 or 234, both
dated May 18, 2002, at a TIS that does not coincide with a scheduled
inspection following this AD, then inspect at the time of cold
working and then begin the 1,600/1,200 hour TIS inspection
intervals.
Note 2: If you have modified your airplane prior to accumulating
4,000 hours TIS, then you may continue to fly your airplane past
modification + 4,000 hours TIS provided you cut your inspection
intervals in half. Upon accumulating 8,000 hours TIS, you must
comply with step 7 above. See example:
Example: An AT-502B had the two-part modification installed at
3,000 hours TIS and the bolt holes have not been cold worked. The
first inspection would occur at 4,600 hours TIS, followed by
inspections at 5,400, 6,200 and 7,000 hours TIS. This airplane may
continue to fly if inspected again at 7,400 and 7,800 hours TIS
(this is at 400 hour TIS intervals instead of 800 hours TIS
intervals). Upon accumulating 8,000 hours TIS, you must modify the
wing following Step 7 above.
8. If you have elected to use repetitive inspections in this
AMOC instead of the safe life, you must make a logbook entry as
follows:
``Following AD 2002-26-05, at XXXX {insert hours TIS{time}
hours TIS an eddy-current inspection has been performed. As of now,
the safe life listed in the AD no longer applies to this airplane.
This airplane must be eddy-current inspected at intervals not to
exceed {800/600/1,200/1,600 as applicable{time} hours TIS.''
For Model AT-502B airplanes, serial number 0643 and all serial
numbers beginning with 0655, you may extend your safe life as an
alternative to the safe life requirement of AD 2002-26-05, as
follows:
1. Upon accumulating 2,100 hours TIS, perform an eddy-current
inspection of the outboard two bolt holes of the lower spar wing
center splice following PS 197, dated June 4, 2002.
2. If no cracks are found, then you may fly an additional 1,000
hours TIS.
3. You must replace the lower spar caps before further flight if
cracks are found or upon accumulating the additional 1,000 hours
TIS, whichever occurs first.
Issued in Kansas City, Missouri, on February 3, 2005.
Nancy C. Lane,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-2507 Filed 2-8-05; 8:45 am]
BILLING CODE 4910-13-P