AD 2001-01-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky Aircraft Corporation | S-76A | Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76A, S-76B, and S-76C Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-76B | Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76A, S-76B, and S-76C Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-76C | Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76A, S-76B, and S-76C Helicopters |
Unsafe Condition
Corrosion due to dissimilar metals in the main landing gear positioning rod assembly and side brace rod end can cause failure of the rod end, leading to landing gear collapse and subsequent loss of control during landing.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the rod assembly and rod end for corrosion within 14 days. Replace any corroded parts with airworthy parts before further flight. Conduct repetitive inspections for corrosion on certain rod ends at intervals not exceeding 90 days, and on other rod ends at intervals not exceeding 12 months or 1,500 hours time-in-service, whichever occurs first.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 14 days for initial inspection; repetitive inspections at specified intervals thereafter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Sikorsky Aircraft Corporation Model S-76A, S-76B, and S-76C helicopters up to and including serial number 760513, with positioning rod assembly (part number 1945E-31A or 2071-31) or side brace rod end (part number 1945E-235 or 2071-235) installed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
This amendment adopts a new airworthiness directive (AD) for Sikorsky Aircraft Corporation (Sikorsky) Model S-76A, S-76B, and S-76C helicopters. This AD requires initial and repetitive inspections of the main landing gear positioning rod assembly (rod assembly) and the side brace rod end (rod end) for corrosion. If any corrosion is found, this AD requires replacing any part that is corroded with an airworthy part before further flight. This amendment is prompted by a landing gear collapse caused by corrosion due to dissimilar metals in the landing gear rod end. The actions specified in this AD are intended to detect corrosion of the threaded joint in the rod assembly to prevent a collapse of the landing gear, and subsequent loss of control of the helicopter during landing.
Document Text
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[Federal Register Volume 66, Number 12 (Thursday, January 18, 2001)]
[Rules and Regulations]
[Pages 4654-4655]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-1121]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2000-SW-52-AD; Amendment 39-12074; AD 2001-01-04]
RIN 2120-AA64
Airworthiness Directives; Sikorsky Aircraft Corporation Model S-
76A, S-76B, and S-76C Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) for
Sikorsky Aircraft Corporation (Sikorsky) Model S-76A, S-76B, and S-76C
helicopters. This AD requires initial and repetitive inspections of the
main landing gear positioning rod assembly (rod assembly) and the side
brace rod end (rod end) for corrosion. If any corrosion is found, this
AD requires replacing any part that is corroded with an airworthy part
before further flight. This amendment is prompted by a landing gear
collapse caused by corrosion due to dissimilar metals in the landing
gear rod end. The actions specified in this AD are intended to detect
corrosion of the threaded joint in the rod assembly to prevent a
collapse of the landing gear, and subsequent loss of control of the
helicopter during landing.
DATES: Effective February 2, 2001.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of February 2, 2001.
Comments for inclusion in the Rules Docket must be received on or
before March 19, 2001.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Office of the Regional Counsel, Southwest Region,
Attention: Rules Docket No. 2000-SW-52-AD, 2601 Meacham Blvd., Room
663, Fort Worth, Texas 76137. You may also send comments electronically
to the Rules Docket at the following address: <a href="/cdn-cgi/l/email-protection#85bca8e4f6f2a8e4e1e6eae8e8e0ebf1f6c5e3e4e4abe2eaf3"><span class="__cf_email__" data-cfemail="dfe6f2beaca8f2bebbbcb0b2b2bab1abac9fb9bebef1b8b0a9">[email protected]</span></a>.
The service information referenced in this AD may be obtained from
BF Goodrich Landing Gear Division, Attn.: Kenneth R. Madej, 8000 Marble
Ave., Cleveland, OH 44105, telephone (216) 429-4461, fax (216) 429-
4357. This information may be examined at the FAA, Office of the
Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort
Worth, Texas; or at the Office of the Federal Register, 800 North
Capitol Street, NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Jeffrey Lee, Aviation Safety Engineer,
Boston Aircraft Certification Office, 12 New England Executive Park,
Burlington, MA 01803, telephone (781) 238-7161, fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: This amendment adopts a new AD for Sikorsky
Model S-76A, S-76B, and S-76C helicopters. This AD requires, within 14
days, inspecting the rod assembly, part number (P/N) 1945E-31A or 2071-
31, and rod end, P/N 1945E235 or 2071-235, for corrosion. If the rod
assembly and rod end were inspected and reassembled in accordance with
BF Goodrich Component Maintenance Manual with Illustrated Parts List,
1945/2071 Series Main Landing Gear, No. 32-10-01, (formerly titled
Cleveland Pneumatic Maintenance Manual 32-10-01), Revision 4, dated
December 15, 1994, within the past 24 months, this AD requires an
inspection within 90 days. If any corrosion is found, this AD requires
replacing the unairworthy part with an airworthy part before further
flight. This AD also requires, at intervals not to exceed 90 days, a
repetitive inspection for corrosion on certain rod ends. For other rod
ends, this AD requires a repetitive inspection for corrosion at
intervals not to exceed 12 months or 1,500 hours time-in-service,
whichever occurs first. This AD is prompted by a landing gear collapse
on a helicopter that was in a hangar. Analysis showed that corrosion
due to dissimilar metals in the rod end caused the rod end to fail with
subsequent collapse of the landing gear. The actions specified in this
AD are intended to detect corrosion of the threaded joint in the rod
assembly and prevent a collapse of the landing gear and subsequent loss
of control of the helicopter during landing.
The FAA has reviewed BF Goodrich Landing Gear Service Bulletin No.
76A-32-03, Revision 1, dated September 15, 2000, which describes
procedures for inspecting and repairing or replacing the rod end and
rod assembly.
Since an unsafe condition has been identified that is likely to
exist or develop on other Sikorsky Model S-76A, S-76B, and S-76C
helicopters of the same type design, this AD is being issued to detect
corrosion of the threaded joint in the rod assembly and prevent a
collapse of the landing gear. This AD requires inspecting the rod
assembly and rod end for corrosion at specified intervals and
replacing, before further flight, any component that has corrosion. The
actions must be accomplished in accordance with the service bulletin
described previously. The short compliance time involved is required
because the previously described critical unsafe condition can
adversely affect the structural integrity of the helicopter. Therefore,
the actions previously mentioned are required within 14 days, and this
AD must be issued immediately.
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
The FAA estimates that 180 helicopters will be affected by this AD
and that it will take approximately 4.5 work hours per helicopter to
inspect the rod assembly and rod end and 1.5 work hours to remove and
replace the rod assembly and rod end, if necessary. Required parts will
cost approximately $14,600 per helicopter. Based on these figures, the
total cost impact of the AD on U.S. operators is estimated to be
$2,692,800 ($14,960 per helicopter, assuming inspecting, removing, and
replacing the rod assembly and rod end once).
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public 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 under the caption ADDRESSES. 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
[[Page 4655]]
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 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 mailed
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. 2000-SW-52-AD.'' The postcard will be date
stamped and returned to the commenter.
The regulations adopted herein will 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. Therefore, it
is determined that this final rule does not have federalism
implications under Executive Order 13132.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and that it 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.
A copy of it, if filed, may be obtained from the Rules Docket at the
location provided under the caption ADDRESSES.
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 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive
to read as follows:
2001-01-04 Sikorsky Aircraft Corporation: Amendment 39-12074. Docket
No. 2000-SW-52-AD.
Applicability: Model S-76A, S-76B, and S-76C helicopters up to
and including serial number 760513 with positioning rod assembly
(rod assembly), part number (P/N) 1945E-31A or 2071-31, or side
brace rod end (rod end), P/N 1945E-235 or 2071-235, installed,
certificated in any category.
Note 1: This AD applies to each helicopter identified in the
preceding applicability provision, regardless of whether it has been
otherwise modified, altered, or repaired in the area subject to the
requirements of this AD. For helicopters 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, unless accomplished
previously.
To detect corrosion of the threaded joint in the rod assembly
and prevent a collapse of the landing gear and subsequent loss of
control of the helicopter during landing, accomplish the following:
(a) Within 14 days, inspect the rod assembly and rod end for
corrosion in accordance with Section 2., Accomplishment
Instructions, in BF Goodrich Service Bulletin No. 76A-32-03,
Revision 1, dated September 15, 2000 (SB), except that scrapping of
corroded parts is not required. Replace any part that is corroded
with an airworthy part before further flight.
(b) Within 90 days, if the rod assembly and rod end were
inspected and reassembled in accordance with BF Goodrich Component
Maintenance Manual with Illustrated Parts List, 1945/2071 Series
Main Landing Gear, No. 32-10-01, (formerly titled Cleveland
Pneumatic Maintenance Manual 32-10-01), Revision 4, dated December
15, 1994, within the past 24 months, inspect the rod assembly and
rod end in accordance with Section 2. of the SB. Scrapping of
corroded parts is not required. Replace any part that is corroded
with an airworthy part before further flight.
(c) At intervals not to exceed 90 days, for rod ends that are
not reassembled with Mastinox sealant or reassembled with Mastinox
sealant but without cadmium plate restoration, inspect the rod
assembly and rod end for corrosion in accordance with the Section 2.
of the SB, except that scrapping of corroded parts is not required.
Replace any part that is corroded with an airworthy part before
further flight.
(d) At intervals not to exceed 12 months or 1,500 hours time-in-
service, whichever occurs first, for rod ends assembled with
Mastinox sealant and cadmium plate restoration or for rod ends
reassembled with Mastinox but that did not previously require rework
due to corrosion, inspect the rod assembly and rod end for corrosion
in accordance with the Section 2. of the SB, except that scrapping
of corroded parts is not required. Replace any part that is corroded
with an airworthy part before further flight.
(e) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Boston Aircraft Certification
Office (ACO), FAA. Operators shall submit their requests through an
FAA Principal Maintenance Inspector, who may concur or comment and
then send it to the Manager, Boston ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Boston ACO.
(f) Special flight permits may be issued in accordance with
Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR
21.197 and 21.199) to operate the helicopter to a location where the
requirements of this AD can be accomplished.
(g) The inspections shall be done in accordance with Section 2.,
Accomplishment Instructions, in BF Goodrich Service Bulletin No.
76A-32-03, Revision 1, dated September 15, 2000. 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 BF Goodrich Landing Gear Division, Attn.: Kenneth R.
Madej, 8000 Marble Ave., Cleveland, OH 44105, telephone (216) 429-
4461, fax (216) 429-4357. Copies may be inspected at the FAA, Office
of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room
663, Fort Worth, Texas; or at the Office of the Federal Register,
800 North Capitol Street, NW., suite 700, Washington, DC.
(h) This amendment becomes effective on February 2, 2001.
Issued in Fort Worth, Texas, on January 5, 2001.
Henry A. Armstrong,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 01-1121 Filed 1-17-01; 8:45 am]
BILLING CODE 4910-13-U
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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