[Federal Register Volume 64, Number 82 (Thursday, April 29, 1999)]
[Rules and Regulations]
[Pages 23016-23017]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-10669]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-SW-49-AD; Amendment 39-11153; AD 99-09-20]
RIN 2120-AA64
Airworthiness Directives; Bell Helicopter Textron Canada (BHTC)
Model 222, 222B, and 222U 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) that
is applicable to BHTC Model 222, 222B, and 222U helicopters. This
action requires initial and repetitive visual inspections and
verification of the torque of the bolts on the main rotor hub. This
amendment is prompted by a report of fatigue cracks around the bolt
holes of the main rotor pitch horn (pitch horn) and a cracked main
rotor flapping bearing assembly (flapping bearing assembly) on a BHTC
Model 222 helicopter. This condition, if not corrected, could result in
fretting-induced fatigue cracking of the flapping bearing assembly and
around the bolt holes of the pitch horn, loss of the rotor system, and
subsequent loss of control of the helicopter.
DATES: Effective May 14, 1999.
Comments for inclusion in the Rules Docket must be received on or
before June 28, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Office of the Regional Counsel, Southwest Region,
Attention: Rules Docket No. 98-SW-49-AD, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas 76137.
FOR FURTHER INFORMATION CONTACT: Harry Edmiston, Aerospace Engineer,
Rotorcraft Certification Office, Rotorcraft Directorate, FAA, 2601
Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5158, fax
(817) 222-5783.
SUPPLEMENTARY INFORMATION: Transport Canada, which is the airworthiness
authority for Canada, has notified the FAA that an unsafe condition may
exist on BHTC Model 222, 222B, and 222U helicopters. Transport Canada
advises that fatigue cracks at the bolt holes of the pitch horn and in
the flapping bearing assembly can lead to loss of control of the
helicopter.
BHTC issued Alert Service Bulletin Nos. 222-98-81 and 222U-98-52,
both dated April 23, 1998 (ASB), which specify inspecting the main
rotor hub in the areas between the pitch horn and main rotor grip tangs
(grip tangs) and between the flapping bearing assembly and the main
rotor yoke assembly for fretting. The ASB's also specify torque
verification procedures for the main rotor grip retaining bolts and the
flapping bearing assembly. Transport Canada classified these ASB's as
mandatory and issued Transport Canada AD CF-98-16, dated July 15, 1998,
in order to assure the continued airworthiness of these helicopters in
Canada.
These helicopter models are manufactured in Canada and are type
certificated for operation in the United States under the provisions of
Sec. 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the
applicable bilateral airworthiness agreement. Pursuant to this
bilateral airworthiness agreement, Transport Canada has kept the FAA
informed of the situation described above. The FAA has examined the
findings of Transport Canada, reviewed all available information, and
determined that AD action is necessary for products of these type
designs that are certificated for operation in the United States.
The FAA estimates that 88 helicopters will be affected by this
proposed AD, that it will take approximately 1 work hour to accomplish
the inspection and retorque of bolts, if necessary, and that the
average labor rate is $60 per work hour. Based on these figures, the
total cost impact of the AD on U.S. operators is estimated to be
$15,840 per year, assuming three inspections and retorques per year and
assuming that no parts will need to be replaced.
Since an unsafe condition has been identified that is likely to
exist or develop on other BHTC Model 222, 222B, and 222U helicopters of
the same type design registered in the United States, this AD is being
issued to prevent fretting induced fatigue cracking of the flapping
bearing assembly and around the bolt holes of the pitch horn, loss of
the rotor system, and subsequent loss of control of the helicopter.
This AD requires recurring inspections of the main rotor hub in the
areas between the pitch horn and grip tangs and between the flapping
bearing assembly and the main rotor yoke assembly for fretting. If
fretting is found on any part, replacing that part with an airworthy
part is required. This AD also requires verifying the torque on the
main rotor grip retaining bolts and the flapping bearing assembly
retaining bolts. The short compliance time involved is required because
the previously described critical unsafe condition can adversely affect
the controllability of the helicopter. Therefore, a visual inspection
of the main rotor hub between the pitch horn and grip tangs and the
flapping bearing assembly and the main rotor yoke assembly for fretting
is required. A torque check of the main rotor grip retaining bolts and
the flapping bearing assembly retaining bolts is also required. These
actions are required within 10 hours TIS 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.
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
[[Page 23017]]
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 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. 98-SW-49-AD.'' The postcard will be date stamped and
returned to the commenter.
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 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, 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:
99-09-20 Bell Helicopter Textron Canada: Amendment 39-11153. Docket
No. 98-SW-49-AD.
Applicability: Model 222 helicopters, serial numbers (S/N) 47006
through 47089, Model 222B helicopters, S/N's 47131 through 47156,
and Model 222U helicopters, S/N's 47501 through 47574, 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 (b) 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 prevent fretting induced fatigue cracking of the main rotor
flapping bearing assembly (flapping bearing assembly) and around the
bolt holes of the main rotor pitch horn (pitch horn), loss of the
rotor system, and subsequent loss of control of the helicopter,
accomplish the following:
(a) Within 10 hours time-in-service (TIS), and thereafter at
intervals not to exceed 150 hours TIS:
(1) Perform a visual inspection of the main rotor hub for
fretting between the pitch horn and main rotor grip tangs (grip
tangs) and between the flapping bearing assembly and the main rotor
yoke assembly. If fretting is found on any part, replace it with an
airworthy part.
(2) Verify the torque of the main rotor grip retaining bolts and
the flapping bearing assembly bolts in the tightening direction,
minimum 100 foot-pounds. If 100 foot-pounds torque is reached
without movement of the bolts, torque bolts to 125 foot-pounds.
(3) If any bolt moves before 100 foot-pounds torque is reached,
remove the pitch horn or the flapping bearing assembly, as
applicable, from the main rotor hub assembly for further inspection.
Inspect the pitch horn or flapping bearing assembly, as applicable,
and all faying surfaces of the pitch horn, flapping bearing
assembly, buffers, main rotor yoke assembly, and the grip tangs for
fretting. If fretting is found on any part, replace it with an
airworthy part.
(4) Apply corrosion preventive compound to the exposed portions
of the bolts and nuts.
Note 2: Bell Helicopter Textron Alert Service Bulletin Nos. 222-
98-81 and 222U-98-52, both dated April 23, 1998, pertain to the
subject of this AD.
(b) 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, Rotorcraft Certification Office,
FAA, Rotorcraft Directorate. Operators shall submit their requests
through an FAA Principal Maintenance Inspector, who may concur or
comment and then send it to the Manager, Rotorcraft Certification
Office.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Rotorcraft Certification Office.
(c) 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 helicopter to a location where
the requirements of this AD can be accomplished.
(d) This amendment becomes effective on May 14, 1999.
Note 3: The subject of this AD is addressed in Transport Canada
(Canada) AD CF-98-16, dated July 15, 1998.
Issued in Fort Worth, Texas, on April 22, 1999.
Henry A. Armstrong,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 99-10669 Filed 4-28-99; 8:45 am]
BILLING CODE 4910-13-P
