[Federal Register Volume 63, Number 147 (Friday, July 31, 1998)]
[Proposed Rules]
[Pages 40846-40849]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-20440]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-CE-65-AD]
RIN 2120-AA64
Airworthiness Directives; Fairchild Aircraft, Inc. SA226 and
SA227 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes to adopt a new airworthiness directive
(AD) that would apply to certain Fairchild Aircraft, Inc. (Fairchild)
SA226 and SA227 series airplanes. The proposed AD would require
repetitively inspecting the wing spar center web cutout on both wings
for cracks between Wing Station (WS) 8 and WS 17.5, and immediately
repairing any area found cracked. This repair would eliminate the need
for the repetitive inspections on that particular wing spar. The
proposed AD is the result of reports of cracks in the wing spar center
web cutout caused by fatigue due to airplane maneuvering and wind
gusts. The
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actions specified by the proposed AD are intended to detect and correct
fatigue cracking of the wing spar center web cutout area, which could
result in structural failure of the wing spar to the point of failure
with consequent loss of control of the airplane.
DATES: Comments must be received on or before September 30, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Central Region, Office of the Regional Counsel,
Attention: Rules Docket No. 98-CE-65-AD, Room 1558, 601 E. 12th Street,
Kansas City, Missouri 64106. Comments may be inspected at this location
between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted.
Service information that applies to the proposed AD may be obtained
from Field Support Engineering, Fairchild Aircraft, Inc., P.O. Box
790490, San Antonio, Texas 78279-0490; telephone: (210) 824-9421;
facsimile: (210) 820-8609. This information also may be examined at the
Rules Docket at the address above.
FOR FURTHER INFORMATION CONTACT: Mr. Hung Viet Nguyen, FAA, Airplane
Certification Office, 2601 Meacham Boulevard, Fort Worth, Texas 76193-
0150; telephone: (817) 222-5155; facsimile: (817) 222-5960.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications should identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report that summarizes each FAA-public contact concerned
with the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket No. 98-CE-65-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Central Region, Office of the Regional Counsel, Attention:
Rules Docket No. 98-CE-65-AD, Room 1558, 601 E. 12th Street, Kansas
City, Missouri 64106.
Discussion
The FAA has received several reports of cracks in the center web of
the wing main spar on Fairchild SA226 and SA227 series airplanes. In a
recent occurrence, cracks were found during a regular maintenance
inspection in the area between Wing Station (WS) 8 and WS 17.5. The
cracks initiated from the corners of the String #13 cutout with one
crack running towards the upper spar cap, and another heading in the
opposite direction.
Analysis of the areas that are cracking on the referenced airplanes
indicates that gust loads and normal airplane maneuvering are the cause
of the cracks.
This condition, if not detected and corrected in a timely manner,
could result in structural failure of the wing spar to the point of
failure with consequent loss of control of the airplane.
Relevant Service Information
Fairchild Aircraft has issued the following documents:
--Airframe Airworthiness Limitations Manual ST-UN-M001, Rev. No. C-6,
dated April 7, 1998, which specifies, among other things, procedures
for inspecting the wing spar center web cutout for cracks between WS 8
and WS 17.5 in the area of Stringer 13 on Models SA227-TT, SA227-AT,
SAA227-AC, and SA227-BC airplanes;
--Airframe Inspection Manual ST-UN-M002, Rev. No. A-6, dated December
8, 1997, which specifies, among other things, procedures for inspecting
the wing spar center web cutout for cracks between WS 8 and WS 17.5 in
the area of Stringer 13 on Models SA226-T, SA226-T(B), SA226-AT, and
SA226-TC airplanes;
--Airframe Airworthiness Limitations Manual ST-UN-M003, Rev. No. 5,
dated April 7, 1998, which specifies, among other things, procedures
for inspecting the wing spar center web cutout for cracks between WS 8
and WS 17.5 in the area of Stringer 13 on Models SA227-CC and SA227-DC
airplanes;
--SA226/227 Series Structural Repair Manual, part number (P/N) 27-
10054-079, pages 57 through 90; Initial Issue: March 1, 1983; Revision
28, dated June 24, 1998. This document specifies procedures for
repairing cracks at the wing spar center web cutout between WS 8 and WS
17.5 in the area of Stringer 13 on Models SA226-T, SA226-T(B), SA226-
AT, SA226-TC, SA227-TT, SA227-AT, SA227-AC, and SA227-BC airplanes; and
--SA227 Series Structural Repair Manual, P/N 27-10054-127, pages 47
through 60; Initial Issue: December 1, 1991; Revision 7, dated June 24,
1998. This document specifies procedures for repairing cracks at the
wing spar center web cutout between WS 8 and WS 17.5 in the area of
Stringer 13 on Models SA227-CC and SA227-DC airplanes.
The FAA's Determination
After examining the circumstances and reviewing all available
information related to the incidents described above, the FAA has
determined that AD action should be taken to detect and correct fatigue
cracking of the wing spar center web cutout area. A cracked wing spar
center web cutout area could result in structural failure of the wing
spar to the point of failure with consequent loss of control of the
airplane.
Explanation of the Provisions of the Proposed AD
Since an unsafe condition has been identified that is likely to
exist or develop in other Fairchild SA226 and SA227 series airplanes of
the same type design, the FAA is proposing AD action. The proposed AD
would require repetitively inspecting the wing spar center web cutout
on both wings for cracks between WS 8 and WS 17.5, and immediately
repairing any area found cracked. This repair would eliminate the need
for the repetitive inspections on that particular wing spar.
Accomplishment of the proposed actions would be required in accordance
with the service information previously referenced.
Cost Impact
The FAA estimates that 490 airplanes in the U.S. registry would be
affected by the proposed AD, that it would take approximately 5
workhours per airplane to accomplish the proposed initial inspection,
and that the average labor rate is approximately $60 an hour. Based on
these figures, the total cost impact of the initial inspection
specified
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in the proposed AD on U.S. operators is estimated to be $147,000, or
$300 per airplane.
These figures only take into account the costs of the proposed
initial inspection and do not take into account the costs of repetitive
inspections and the costs associated with any repair that would be
necessary if corrosion or delamination damage is found. The FAA has no
way of determining the number of repetitive inspections an owner/
operator will incur over the life of the airplane, or the number of
airplanes that will need repairs.
If an affected airplane would have cracks in both wing spar center
webs, the repair would take 400 workhours to accomplish at an average
labor rate of $60 per hour. Parts to accomplish this repair cost
approximately $400 per airplane. Based on these figures, the cost to
repair cracked wing spar center webs on both sides of the airplane
would be approximately $24,400 per airplane.
Regulatory Impact
The regulations proposed herein would not have substantial direct
effects 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. Therefore, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this action (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); and (3) if promulgated,
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. A copy of the draft regulatory evaluation
prepared for this action has been placed in the Rules Docket. A copy of
it may be obtained by contacting the Rules Docket at the location
provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding a new airworthiness directive
(AD) to read as follows:
Fairchild Aircraft, Inc.: Docket No. 98-CE-65-AD.
Applicability: The following model airplanes and serial numbers,
certificated in any category:
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Model Serial No.
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SA226-AT.............................. AT001 through AT074.
SA226-TC.............................. TC201 through TC419.
SA226-T............................... T201 through T291.
SA226-T(B)............................ T(B)276 and T(B)292 through
T(B)417.
SA227-TT.............................. TT421 through TT541.
SA227-TT(300)......................... TT(300)447, TT(300)465,
TT(300)471, TT(300)483,
TT(300)512, TT(300)518,
TT(300)521, TT(300)527,
TT(300)529, and TT(300)536.
SA227-AC.............................. AC406, AC415, AC416, and AC420
through AC785.
SA227-AT.............................. AT423 through AT631 and AT695.
SA227-BC.............................. BC762, BC764, BC766, and BC770
through BC789.
SA227-CC/DC........................... CC/DC784 and CC/DC790 through CC/
DC878.
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Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
alternative method of compliance in accordance with paragraph (e) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated in the body of this AD, unless
already accomplished.
To detect and correct fatigue cracking of the wing spar center
web cutout area, which could result in structural failure of the
wing spar to the point of failure with consequent loss of control of
the airplane, accomplish the following:
(a) Upon accumulating 6,500 hours time-in-service (TIS) on each
wing spar or within the next 500 hours TIS after the effective date
of this AD, whichever occurs later, unless already accomplished, and
thereafter at intervals not to exceed 2,000 hours TIS, inspect each
wing spar center web cutout for cracks between Wing Station (WS) 8
and WS 17.5. Accomplish this inspection in accordance with one of
the following, as applicable:
(1) For Models SA227-TT, SA227-AT, SAA227-AC, and SA227-BC
airplanes: In accordance with Fairchild Airframe Airworthiness
Limitations Manual ST-UN-M001, Rev. No. C-6, dated April 7, 1998;
(2) For Models SA226-T, SA226-T(B), SA226-AT, and SA226-TC
airplanes: In accordance with Fairchild Airframe Inspection Manual
ST-UN-M002, Rev. No. A-6, dated December 8, 1997; or
(3) For Models SA227-CC and SA227-DC airplanes: In accordance
with Fairchild Airframe Airworthiness Limitations Manual ST-UN-M003,
Rev. No. 5, dated April 7, 1998.
(b) If any crack(s) is/are found during any inspection required
by paragraph (a) of this AD, prior to further flight, repair the
crack(s) in accordance with one of the following, as applicable.
This repair eliminates the repetitive inspections (2,000 hours TIS
intervals) required in paragraph (a) of this AD for that particular
wing spar.
(1) For Models SA226-T, SA226-T(B), SA226-AT, SA226-TC, SA227-
TT, SA227-AT, SA227-AC, and SA227-BC airplanes: In accordance with
Fairchild SA226/227 Series Structural Repair Manual, part number (P/
N) 27-10054-079, pages 57 through 90; Initial Issue: March 1, 1983;
Revision 28, dated June 24, 1998; or
(2) For Models SA227-CC and SA227-DC airplanes: In accordance
with Fairchild SA227 Series Structural Repair Manual, P/N 27-10054-
127, pages 47 through 60; Initial Issue: December 1, 1991; Revision
7, dated June 24, 1998.
(c) The repetitive inspections required by paragraph (a) of this
AD may be terminated if the wing spar center web repair specified in
paragraph (b) of this AD has been accomplished on both the left and
right wing spar. If one wing spar center web has been repaired, then
repetitive inspections are still required on the other one if the
repair has not been incorporated.
(d) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be accomplished.
(e) An alternative method of compliance or adjustment of the
initial or repetitive compliance times that provides an equivalent
level of safety may be approved by the Manager, FAA, Airplane
Certification Office (ACO), 2601 Meacham Boulevard, Fort Worth,
Texas 76193-0150. The request shall be forwarded through an
appropriate FAA Maintenance Inspector, who may add comments and then
send it to the Manager, Forth Worth ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Fort Worth ACO.
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(f) All persons affected by this directive may obtain copies of
the documents referred to herein upon request to Field Support
Engineering, Fairchild Aircraft, Inc., P.O. Box 790490, San Antonio,
Texas 78279-0490; or may examine these documents at the FAA, Central
Region, Office of the Regional Counsel, Room 1558, 601 E. 12th
Street, Kansas City, Missouri 64106.
Issued in Kansas City, Missouri, on July 23, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-20440 Filed 7-30-98; 8:45 am]
BILLING CODE 4910-13-U
