[Federal Register Volume 61, Number 178 (Thursday, September 12, 1996)]
[Rules and Regulations]
[Pages 48066-48069]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-22951]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-CE-10-AD; Amendment 39-9753; AD 96-19-05]
RIN 2120-AA64
Airworthiness Directives; Fairchild Aircraft SA226 and SA227
Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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[[Page 48067]]
SUMMARY: This amendment supersedes Airworthiness Directive (AD) 95-19-
07, which currently requires the following on Fairchild Aircraft SA226
and SA227 series airplanes equipped with certain main landing gear
(MLG) and nose landing gear (NLG): repetitively inspecting, using
ultrasonic methods, the left-hand and right-hand MLG yokes and the NLG
yokes for stress corrosion cracking, and, if any cracked yokes are
found that exceed certain limits, replacing either the cracked yoke,
the yoke/cylinder combination, or the affected MLG or NLG assembly.
This action also supersedes priority letter AD 95-19-07 R1, which was
issued to incorporate revised service information. Reports of landing
gear failures on the affected airplanes prompted the original AD
action. This action requires the same inspections, but requires
replacing any MLG and NLG assembly with any cracks instead of allowing
flight until certain crack limits are exceeded. The inability to
determine or predict crack growth on areas where stress corrosion
occurs on primary structure with a single-load path (MLG and NLG
assemblies are considered such structure) prompted this action. The
actions specified by this AD are intended to prevent MLG or NLG failure
caused by stress corrosion cracking in the yokes, which could result in
loss of control of the airplane during landing operations.
DATES: Effective October 1, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of October 1, 1996.
Comments for inclusion in the Rules Docket must be received on or
before November 7, 1996.
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-10-AD, Room 1558, 601 E.
12th Street, Kansas City, Missouri 64106.
Service information that applies to this AD may be obtained from
Fairchild Aircraft, P.O. Box 790490, San Antonio, Texas 78279-0490;
telephone (210) 824-9421. This information may also be examined at the
FAA, Central Region, Office of the Assistant Chief Counsel, Attention:
Rules Docket 96-CE-10-AD, Room 1558, 601 E. 12th Street, Kansas City,
Missouri 64106; or at the Office of the Federal Register, 800 North
Capitol Street, NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Mr. Hung Viet Nguyen, Aerospace
Engineer, FAA, Airplane Certification Office, 2601 Meacham Boulevard,
Fort Worth, Texas 76193-0150; telephone (817) 222-5155; facsimile (817)
222-5960.
SUPPLEMENTARY INFORMATION:
Events Leading to the Issuance of AD 95-19-07
Several reports of main landing gear (MLG) and nose landing gear
(NLG) failure on Fairchild Aircraft SA226 and SA227 series airplanes
prompted the FAA to issue Airworthiness Directive (AD) 95-19-07,
Amendment 39-9369 (60 FR 47687, September 14, 1995). AD 95-19-07
required the following on Fairchild Aircraft SA226 and SA227 series
airplanes equipped with certain MLG and NLG: repetitively inspecting,
using ultrasonic methods, the left-hand and right-hand MLG yokes and
the NLG yokes for stress corrosion cracking, and, if any cracked yokes
are found that exceed certain limits, replacing either the cracked
yoke, the yoke/cylinder combination, or the affected MLG or NLG
assembly. Accomplishment of the inspections required by AD 95-19-07 was
required in accordance with Fairchild Service Bulletin (SB) 226-32-065,
Fairchild SB 227-32-039, or Fairchild SB CC7-32-007, all Issued: August
16, 1995, as applicable.
The airplanes in the above-referenced incidents are equipped with
at least one part number (P/N) OAS5453 MLG assembly and P/N OAS5451 NLG
assembly. Metallurgical analysis of the yokes of the right-hand and
left-hand MLG assemblies and NLG assemblies on several of these
airplanes revealed that the failure was initiated by stress corrosion
cracking of the yokes.
Explanation of the Relevant Service Information
The service bulletins incorporated into AD 95-19-07 contain some
incorrect procedures that could prevent an owner/operator from
correctly accomplishing the actions required by that AD. For this
reason, Fairchild Aircraft revised SB 226-32-065, SB 227-32-039, and SB
CC7-32-007, each of which incorporates the following effective pages
and revision levels:
------------------------------------------------------------------------
Effective pages SB date
------------------------------------------------------------------------
1, 5, and 8............................... Revised: September 28, 1995.
2, 3, 4, 6, 7, and 9...................... Issued: August 16, 1995.
------------------------------------------------------------------------
These service bulletins specify improved procedures for ultrasonically
inspecting the left-hand and right-hand Ozone Industries, Inc. MLG yoke
(reference: MLG assembly P/N OAS5453, all dash numbers up to and
including -19), and Ozone Industries, Inc. NLG yoke (reference: NLG
assembly P/N OAS5451, all dash number up to and including -17), on
Fairchild Aircraft SA226 and SA227 series airplanes.
The Need to Revise AD 95-19-07
The FAA determined that the revised service information should be
incorporated into AD 95-19-07 to allow for proper inspection of the MLG
and NLG yokes of the affected airplanes, and issued priority letter AD
95-19-07 R1 to prevent MLG or NLG failure caused by stress corrosion
cracks in the yokes, which could result in loss of control of the
airplane during landing operations. The priority letter revised AD 95-
19-07 by (1) retaining the repetitive inspections and possible
replacement required by AD 95-19-07; and (2) incorporating the revised
service bulletins to require accomplishment of the actions in
accordance with corrected and clarified procedures.
Reason for This Action
After in-depth analysis, the FAA has established a policy to not
allow airplane operation when known cracks exist in primary structure
(MLG and NLG assemblies are considered such structure). The FAA makes
allowances on this policy to account for parts availability provided
analysis shows that an interim, acceptable level of safety can be
maintained through a short-term, repetitive inspection program.
For this reason, the FAA has determined that the crack limits in
priority letter AD 95-19-07 R1 and AD 95-19-07, Amendment 39-9369,
should be eliminated and that AD action should be taken to require
immediate replacement of any cracked MLG or NLG assembly. Because
analysis shows that a repetitive inspection program can provide an
interim acceptable level of safety, the FAA will allow a grace period
for those owners/operators with airplanes where a crack is found in the
MLG or NLG yoke during the initial inspection required by this action.
Explanation of the Provisions of This AD
Since an unsafe condition has been identified that is likely to
exist or develop in other Fairchild Aircraft SA226 and SA227 series
airplanes of the same type design, this AD supersedes both priority
letter AD 95-19-07 R1 and AD 95-19-07, Amendment 39-9369, with a new AD
that retains the requirement of repetitively inspecting, using
ultrasonic methods, the left-hand and right-hand MLG yokes and the NLG
yokes for stress corrosion cracking, and
[[Page 48068]]
requires replacing either the cracked yoke, the yoke/cylinder
combination, or the affected MLG or NLG assembly, if any crack is
found. Accomplishment of the required inspections is in accordance with
Fairchild SB 226-32-065, Fairchild SB 227-32-039, or Fairchild SB CC7-
32-007, as applicable. Each of these service bulletins incorporates the
following effective pages and revision levels:
------------------------------------------------------------------------
Effective pages SB date
------------------------------------------------------------------------
1, 5, and 8............................... Revised: September 28, 1995.
2, 3, 4, 6, 7, and 9...................... Issued: August 16, 1995.
------------------------------------------------------------------------
Accomplishment of the replacement is in accordance with the applicable
maintenance manual.
Since a situation exists (possible loss of control of the airplane
during landing operations) that requires the immediate adoption of this
regulation, it is found that notice and opportunity for public prior
comment hereon are impracticable, and that good cause exists for making
this amendment effective in less than 30 days.
Compliance Time Criteria
The compliance time of this AD is presented in both calendar time
and hours time-in-service (TIS). Cracking of certain MLG yokes and NLG
yokes on the affected airplanes is caused by stress corrosion, which
starts as a result of high local stress (in the area where the piston
was shrink fitted to the yoke) incurred through operation. Corrosion
can then develop regardless of whether the airplane is in flight or on
the ground. The cracks may not be noticed initially as a result of the
stress loads, but could then progress as a result of corrosion. The
stress incurred during flight operations or temperature changes could
then cause rapid crack growth. In order to ensure that these stress
corrosion cracks do not go undetected, a compliance time of specific
hours TIS and calendar time (whichever occurs first) is utilized.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting immediate flight safety and, thus, was not
preceded by notice and opportunity to comment, comments are invited on
this rule. Interested persons are invited to comment on this 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 will be considered,
and this rule may be amended in light of the comments received. Factual
information that supports the commenter's ideas and suggestions is
extremely helpful in evaluating the effectiveness of the AD action and
determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the 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
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket No. 96-CE-10-AD.'' The postcard will be date stamped and
returned to the commenter.
Regulatory Impact
The regulations adopted herein will 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 final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and is not a ``significant regulatory action''
under Executive Order 12866. It has been determined further that this
action involves an emergency regulation under DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979). If it is determined
that this emergency regulation otherwise would be significant under DOT
Regulatory Policies and Procedures, a final regulatory evaluation will
be prepared and placed in the Rules Docket (otherwise, an evaluation is
not required). A copy of it, if filed, may be obtained from the Rules
Docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends 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.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing Airworthiness Directive
(AD) 95-19-07, Amendment 39-9369 (60 FR 47687, September 14, 1995), and
by adding a new AD to read as follows:
96-19-05 Fairchild Aircraft: Amendment 39-9753, Docket No. 96-CE-
10-AD. Supersedes both AD 95-19-07, Amendment 39-9369, and priority
letter AD 95-19-07 R1.
Applicability: Models SA226-T, SA226-AT, SA226-TC, SA226-T(B),
SA227-AC, SA227-AT, SA227-BC, SA227-TT, SA227-CC, and SA227-DC
airplanes (all serial numbers), certificated in any category, that
are equipped with one or more of the following:
1. Ozone Industries, Inc. main landing gear (MLG) yoke
(reference: MLG assembly part number OAS5453, all dash numbers up to
and including -19); or
2. Ozone Industries, Inc. nose landing gear (NLG) yoke
(reference: NLG assembly part number OAS5451, all dash numbers up to
and including -17).
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 (g) 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 initially as follows and thereafter
as indicated in the body of this AD:
1. Within the next 100 hours time-in-service (TIS) after the
effective date of this AD or within the next 3 months after the
effective date of this AD, whichever occurs first; and
2. Upon the installation of one of the affected MLG or NLG
assemblies or yokes.
To prevent MLG or NLG failure caused by stress corrosion cracks
in the yokes, which could result in loss of control of the airplane
during landing operations, accomplish the following:
[[Page 48069]]
(a) Inspect, using ultrasonic methods, both sides of the left-
hand and right-hand MLG and NLG yokes for stress corrosion cracking
in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of
Fairchild Service Bulletin (SB) 226-32-065, Fairchild SB 227-32-039,
or Fairchild SB CC7-32-007, as applicable. Each of these service
bulletins incorporates the following effective pages and revision
levels:
------------------------------------------------------------------------
Effective pages SB date
------------------------------------------------------------------------
1, 5, and 8............................... Revised: September 28, 1995.
2, 3, 4, 6, 7, and 9...................... Issued: August 16, 1995.
------------------------------------------------------------------------
(b) If no cracks are found during the initial inspection
required by paragraph (a) of this AD, accomplish the following:
(1) Prior to further flight after the initial inspection
required by this AD, clean the MLG and NLG yoke and piston in
accordance with FIGURE 2 of the service bulletins referenced in this
AD, unless already accomplished;
(2) Prior to further flight after the initial inspection
required by this AD, apply a small bead of Products Research and
Chemical Corporation PR-1422 or PR-1435 sealant to the MLG and NLG
yoke as shown in FIGURE 2 of the service bulletins referenced in
this AD, and as described in the SA226/227 Series Service Repair
Manual, Chapter 51-30-03, Standard Practices--Sealing, unless
already accomplished; and
(3) Reinspect the MLG and NLG yokes at intervals not to exceed
2,500 hours TIS or 12 months, whichever occurs first, provided no
cracks are found. If cracks are found, prior to further flight,
replace the cracked part with a new or serviceable part in
accordance with the applicable maintenance manual, and accomplish
the cleaning of and sealant application to the MLG and NLG yoke and
piston as specified in paragraphs (b)(1) and (b)(2) of this AD. The
replacement may be accomplished by replacing the cracked yoke, the
total gear assembly, or the yoke/cylinder combination.
(c) If a crack is found during the initial inspection of this
AD, replace the cracked part with a new or serviceable part in
accordance with the applicable maintenance manual, and accomplish
the cleaning of and sealant application to the MLG and NLG yoke and
piston as specified in paragraphs (b)(1) and (b)(2) of this AD. The
replacement may be accomplished by replacing the cracked yoke, the
total gear assembly, or the yoke/cylinder combination. Replace any
cracked part in accordance with the following schedule:
(1) With a crack found with a length more than 1.5 inches in
length: PRIOR TO FURTHER FLIGHT;
(2) With a crack found with a length more than 1 inch but not
more than 1.5 inches: WITHIN THE NEXT 300 HOURS TIS AFTER THE
INITIAL INSPECTION REQUIRED BY THIS AD OR WITHIN THE NEXT 60 DAYS
AFTER THE INITIAL INSPECTION REQUIRED BY THIS AD, WHICHEVER OCCURS
FIRST;
(3) With a crack found with a length more than .75 inch but not
more than 1 inch: WITHIN THE NEXT 400 HOURS TIS AFTER THE INITIAL
INSPECTION REQUIRED BY THIS AD OR WITHIN THE NEXT 80 DAYS AFTER THE
INITIAL INSPECTION REQUIRED BY THIS AD, WHICHEVER OCCURS FIRST;
(4) With a crack found with a length more than .50 inch but not
more than .75 inch: WITHIN THE NEXT 500 HOURS TIS AFTER THE INITIAL
INSPECTION REQUIRED BY THIS AD OR WITHIN THE NEXT 100 DAYS AFTER THE
INITIAL INSPECTION REQUIRED BY THIS AD, WHICHEVER OCCURS FIRST; and
(5) With a crack found with a length less than 0.50 inch: WITHIN
THE NEXT 600 HOURS TIS AFTER THE INITIAL INSPECTION REQUIRED BY THIS
AD OR WITHIN THE NEXT 120 DAYS AFTER THE INITIAL INSPECTION REQUIRED
BY THIS AD, WHICHEVER OCCURS FIRST.
(d) Replacing a MLG or NLG yoke with either Ozone Industries,
Inc. MLG yoke (reference: MLG assembly part number OAS5453, all dash
numbers up to and including--19), or Ozone Industries, Inc. NLG yoke
(reference: NLG assembly part number OAS5451, all dash numbers up to
and including--17) re-establishes the effectivity of this AD.
(1) Repetitive inspections are required upon installation and at
intervals not to exceed 2,500 hours TIS or 12 months, whichever
occurs first, provided no cracks are found.
(2) If cracks are found, prior to further flight, replace the
cracked part with a new or serviceable part in accordance with the
applicable maintenance manual, and accomplish the cleaning of and
sealant application to the MLG and NLG yoke and piston as specified
in paragraphs (b)(1) and (b)(2) of this AD. The replacement may be
accomplished by replacing the cracked yoke, the total gear assembly,
or the yoke/cylinder combination.
(3) The crack limit replacement compliance times specified in
paragraph (c) of this AD only apply when cracks are found during the
initial inspection required by this AD. If any crack of any length
is found during a subsequent (any repetitive) inspection, the part
must be replaced PRIOR TO FURTHER FLIGHT.
(e) The MLG and NLG yokes to which this AD applies are
manufactured by Ozone Industries, Inc. Replacing these yokes with
approved parts, other than the following Ozone Industries, Inc. MLG
and NLG yokes eliminates the repetitive inspection requirements of
this AD:
(1) Ozone Industries, Inc. MLG yoke (reference: MLG assembly
part number OAS5453, all dash numbers up to and including--19).
(2) Ozone Industries, Inc. NLG yoke (reference: NLG assembly
part number OAS5451, all dash numbers up to and including--17).
(f) 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.
(g) An alternative method of compliance or adjustment of the
compliance time that provides an equivalent level of safety may be
approved by the Manager, Airplane Certification Office (ACO), FAA,
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
ACO. Alternative methods of compliance approved in accordance with
either priority letter AD 95-19-07 R1 or AD 95-19-07, Amendment 39-
9369 (both superseded by this action), are not considered approved
as alternative methods of compliance with this AD.
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.
(h) The inspections required by this AD shall be done in
accordance with Fairchild Service Bulletin 226-32-065, Fairchild
Service Bulletin 227-32-039, or Fairchild Service Bulletin CC7-32-
007, as applicable. Each of these service bulletins incorporates the
following effective pages and revision levels:
------------------------------------------------------------------------
Effective pages SB date
------------------------------------------------------------------------
1, 5, and 8............................... Revised: September 28, 1995.
2, 3, 4, 6, 7, and 9...................... Issued: August 16, 1995.
------------------------------------------------------------------------
This incorporation by reference was approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. Copies may be obtained from Fairchild Aircraft, P.O. Box 790490,
San Antonio, Texas 78279-0490. Copies may be inspected at the FAA,
Central Region, Office of the Assistant Chief Counsel, Room 1558,
601 E. 12th Street, Kansas City, Missouri, or at the Office of the
Federal Register, 800 North Capitol Street, NW, suite 700,
Washington, DC.
(i) This amendment (39-9753) supersedes AD 95-19-07, Amendment
39-9369, and priority letter AD 95-19-07 R1.
(j) This amendment (39-9753)1 becomes effective on October 1,
1996.
Issued in Kansas City, Missouri, on September 3, 1996.
Henry A. Armstrong,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-22951 Filed 9-11-96; 8:45 am]
BILLING CODE 4910-13-U
