[Federal Register Volume 62, Number 112 (Wednesday, June 11, 1997)]
[Proposed Rules]
[Pages 31766-31769]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-15174]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-CE-58-AD]
RIN 2120-AA64
Airworthiness Directives; Fairchild Aircraft Incorporated Models
SA226-TC, SA226-T, SA226-T(B), and SA226-AT 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 Incorporated
(Fairchild) Models SA226-TC, SA226-T, SA226-T(B), and SA226-AT
airplanes. The proposed AD would require inspecting the center flap
hinge and wing trailing edge ribs at the flap actuator attach brackets
for cracks and if no cracks are found, installing a doubler on the rib,
or replacing a cracked rib with a new rib assembly that is reinforced
with a doubler. Fatigue cracks at the center flap hinge and the support
link has resulted in concentrated stress on the wing trailing edge ribs
which prompted the proposed action. The actions specified by the
proposed AD are intended to prevent asymmetrical flap deflection
forcing the airplane into an uncommanded roll and
[[Page 31767]]
could cause loss of control of the airplane.
DATES: Comments must be received on or before August 11, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Central Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket No. 96-CE-58-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 Fairchild Aircraft Inc., P.O. Box 32486, San Antonio, Texas,
78284; telephone (210) 824-9421. This information also may be examined
at the Rules Docket at the address above.
FOR FURTHER INFORMATION CONTACT: Mr. Hung Viet Nguyen, Aerospace
Engineer, FAA, Fort Worth 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. 96-CE-58-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 Assistant Chief Counsel,
Attention: Rules Docket No. 96-CE-58-AD, Room 1558, 601 E. 12th Street,
Kansas City, Missouri 64106.
Events Leading to the Proposed AD
The FAA has received reports of three incidents on certain
Fairchild SA226 series airplanes with fatigue cracks in the wing
trailing edge rib at the center flap hinge. Further investigation shows
that the cracking is relieving the stress load at the support link.
This prevents the flaps from extending to full deflection, which could
result in asymmetrical flap deflection and cause the airplane to go
into an uncommanded roll.
Related Service Information
Fairchild has issued Service Bulletin (SB) SB 57-016, Issued: June
25, 1981; Revised: December 9, 1981, that specifies procedures for
inspecting the wing trailing edge ribs for cracks, if no cracks are
found, installing reinforcement doublers on the ribs, and replacing
ribs that have cracks with new rib assemblies.
(Note: The compliance time in this AD takes precedence over the
compliance time in the Fairchild Service Bulletin referenced above.)
FAA's Determination
After examining the circumstances and reviewing all available
information related to the incidents and service information described
above, the FAA has determined that AD action should be taken to prevent
asymmetrical flap deflection forcing the airplane into an uncommanded
roll and could cause 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 Models SA226-TC, SA226-T, SA226-
T(B), and SA226A-T airplanes of the same type design, the proposed AD
would require:
--Inspecting wing trailing edge ribs at wing stations (WS) 98.385 and
100.635 for cracks,
--Replacing any cracked rib with a new rib assembly (part number (P/N)
27-31085-1/2 or 27-31086-1/2 or FAA equivalent), and
--Installing a reinforcement doubler (P/N 27K36075-7 or FAA
equivalent), whether or not cracks are found.
Cost Impact
The FAA estimates that 240 airplanes in the U.S. registry would be
affected by the proposed AD, that it would take approximately 100
workhours per airplane to accomplish the proposed installation of the
doubler and 180 workhours per airplane to accomplish the proposed
installation of the new rib assembly and doubler, and that the average
labor rate is approximately $60 an hour. Parts cost approximately $133
for both wing rib assemblies per airplane. The doubler can be
manufactured from local materials. Based on these figures, the total
cost impact of the proposed AD on U.S. operators is estimated to be
$2,623,920 for the U.S. fleet or $10,933 per airplane for the rib
assembly and doubler installations. The labor cost for the doubler
installation is $6,000 per airplane and the doubler can be manufactured
from local materials.
Regulatory Flexibility Determination and Analysis
The Regulatory Flexibility Act of 1980 (RFA) was enacted by
Congress to ensure that small entities are not unnecessarily or
disproportionately burdened by government regulations. The RFA requires
government agencies to determine whether rules would have a
``significant economic impact on a substantial number of small
entities,'' and, in cases where the rule would have an economic impact,
the agency making the rule is obligated to conduct a Regulatory
Flexibility Analysis in which alternatives to the rule are considered.
FAA Order 2100.14A, Regulatory Flexibility Criteria and Guidance,
outlines FAA procedures and criteria for complying with the RFA. Small
entities are defined as small businesses, small not-for-profit
organizations that are independently owned and operated, or airports
operated by small governmental jurisdictions. A ``substantial number''
is defined as a number that is not less than 11 and that is more than
one-third of the small entities subject to a proposed rule, or any
number of small entities judged to be substantial by the rulemaking
official. A ``significant economic impact'' is defined by an annualized
net compliance cost, adjusted for inflation, which is greater than a
threshold cost level for defined entity types.
There are an estimated 240 Fairchild SA226 series airplanes in the
U.S. registry that could be affected by the proposed action. For many
of these airplanes, it is believed that the actions that are proposed
have already been completed. The entities affected by the proposed AD
are largely grouped in the
[[Page 31768]]
Standard Industrial Classification (SIC) 4512, Operators of Aircraft
for Hire, classified as ``Unscheduled.'' FAA Order 2100.14A, Regulatory
Flexibility Criteria and Guidance, defines a small entity in this
classification as one that owns or operates nine or fewer aircraft.
In order to experience a significant economic impact under Order
2100.14A, an operator of aircraft for hire, unscheduled, would have to
incur annualized costs of $4975 (1996 dollars) or more. Costs are
estimated to be approximately $6,000 per airplane if only the doubler
plates are installed, or as much as $10,933 per airplane if any ribs
are found cracked and a rib assembly replacement is required, in
addition to installing the doubler plate. Annualized costs are
dependent on the required work, the cost of capital for airplane
owners/operators, and the expected length of time that the required
changes are expected to be in use. Since the changes are assumed to be
permanent, the service life of the changes is the remaining life of the
airplane. The cost of capital for the airplane owners/operators is
assumed to be 15 percent. Under these conditions, no owner/operator of
a single airplane would be subject to significant costs if the expected
remaining service life of the aircraft were more than:
(a) 1.43 years (approximately 17 months), if the doubler plate
installation is required; or
(b) 2.9 years (approximately 35 months) if both the doubler plate
installation and rib replacement is required.
Ownership of the new SA226 series airplanes (i.e.: the airplanes
other than the older Model SA226TC) is very widely dispersed. There are
five separate entities (excluding Swearingen) that show ownership of
newer SA226 series airplanes in the U.S. Registry, each of which owns
two SA226 series airplanes. According to the manufacturer, these
airplanes are relatively new with typically less than 10,000 hours
total time-in-service (TIS), and are employed primarily as corporate
aircraft with usage rates at approximately 400 hours TIS per year.
Allocating a nominal remaining service life of 25,000 hours total TIS
(out of a total service life of 35,000 hours) at the rate of 500 hours
TIS per year, suggests remaining lives on the order of 50 years. Even
with a remaining service life of half of this, or 25 years, annualized
costs for both doubler plate installation and rib replacement would be
on the order of $1,715. Thus, an owner of two such airplanes would
experience annualized costs for the proposed AD of approximately
$3,430, which is a figure less than 70 percent of threshold value for
significant cost.
The manufacturer indicates that most of the older Fairchild Model
SA226-TC airplanes (80 of which were listed in the U.S. Registry
records), have probably been modified under the 1981 service bulletin
that will be made mandatory by the AD. Fairchild Model SA226-TC
airplanes in service have average cumulative usage of approximately
25,000 to 30,000 hours total TIS, with a likely average annual usage in
cargo service of 1,000 to 1,500 hours TIS, and an economic life of
35,000 hours total TIS. This suggests that most Fairchild Model SA226-
TC airplanes have remaining lives of about five years (even without
prospective modifications that are likely to extend the life of the
aircraft). A five-year life for an airplane that would be required to
carry out both modifications implies that annualized costs would be
approximately $3,300. Thus, an owner of a single aging unmodified
Fairchild Model SA226-TC airplane would not experience a significant
economic impact.
According to U.S. Registry records, there are 12 entities
(excluding Sweringen) that own 2 or more Fairchild Model SA226-TC
airplanes, accounting for a total of 49 airplanes. Because of the age
of the aircraft and the likelihood of compliance with the original
service bulletin (dated 1981), the FAA believes that significant
impacts will not be felt by most owners of the these airplanes. In
addition, the eight owners of two or more of these airplanes account
for less than one-tenth of the affected entities. For these reasons,
the FAA has determined that the proposed AD would not have a
significant economic impact on a substantial number of small aircraft
operators. The FAA solicits comments concerning the impact of this
proposed AD on small entity owners of affected airplanes. Based on the
possibility that this proposed AD could have a significant impact on a
substantial number of small entities, the FAA conducted a regulatory
flexibility analysis.
A copy of the full Cost Analysis and Regulatory Flexibility
Determination for the proposed action may be examined at the FAA,
Central Region, Office of the Assistant Chief Counsel, Attention: Rules
Docket No. 96-CE-58-AD, Room 1558, 601 E. 12th Street, Kansas City,
Missouri.
FAA's Aging Commuter Aircraft Policy
This action is consistent with the FAA's aging commuter airplane
policy. This policy simply states that reliance on repetitive
inspections of critical areas on airplanes utilized in commuter service
carries an unnecessary safety risk when a design change exists that
could eliminate or, in certain instances, reduce the number of those
critical inspections. The alternative to installing the doubler or the
new rib assembly would be relying on repetitive inspections to detect
damaged wing ribs.
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 USC 106(g), 40113, 44701.
[[Page 31769]]
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. 96-CE-58-AD.
Applicability: The following Models and serial numbered
airplanes, certificated in any category.
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Models Serial Nos.
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SA226-TC.............................. TC201 through TC379.
SA226-T............................... T201 through T275, and T277
through T291.
SA226-T(B)............................ T(B)275, and T(B)292 through
T(B)378.
SA226-AT.............................. AT001 through AT069.
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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 (c) 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 within the next 500 hours time-in-service
(TIS) after the effective date of this AD, unless already
accomplished.
Note 2: The compliance time of this AD takes precedence over the
compliance time in the Fairchild Service Bulletin referenced below.
To prevent asymmetrical flap deflection forcing the airplane
into an uncommanded roll and cause loss of control of the airplane,
accomplish the following:
(a) Inspect both wing trailing edge ribs at the center flap
actuator attach brackets, wing stations (WS) 98.385 and 100.635, for
cracks in accordance with the Accomplishment Instructions section,
Part A, of Fairchild Service Bulletin (SB) 57-016, Issued: June 25,
1981; Revised: December 9, 1981.
(1) If no cracks are found, prior to further flight, install the
reinforcement doubler, part number (P/N) 27K36075-7 or an FAA
approved, in accordance with the Accomplishment Instructions
section, Part B of Fairchild SB 57-016, Issued: June 25, 1981;
Revised: December 9, 1981.
(2) If any cracks are found, prior to further flight, replace
any cracked rib with a new rib assembly (P/N 27-31085-1/2 or 27-
31086-1/2 or an FAA-approved) and install the new reinforcement
doubler (P/N 27K36075-7 or an FAA equivalent) in accordance with the
Accomplishment Instructions section, Part B and Part C of Fairchild
SB 57-016, Issued: June 25, 1981; Revised: December 9, 1981.
(b) 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.
(c) An alternative method of compliance or adjustment of
compliance time that provides an equivalent level of safety may be
approved by the Manager, Fort Worth Airplane Certification Office,
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, Fort Worth
Airplane Certification Office.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Fort Worth Airplane Certification Office.
(d) All persons affected by this directive may obtain copies of
the document referred to herein upon request to Fairchild Aircraft,
Inc., P. O. Box 32486, San Antonio, Texas, 78284; or may examine
this document at the FAA, Central Region, Office of the Assistant
Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri
64106.
Issued in Kansas City, Missouri, on June 4, 1997.
John R. Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-15174 Filed 6-10-97; 8:45 am]
BILLING CODE 4910-13-U