[Federal Register Volume 59, Number 121 (Friday, June 24, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-15408]
Federal Register / Vol. 59, No. 121 / Friday, June 24, 1994 /
[[Page Unknown]]
[Federal Register: June 24, 1994]
VOL. 59, NO. 121
Friday, June 24, 1994
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 92-ASW-49; Amendment 39-8683; AD 93-17-12]
Airworthiness Directives; Bell Helicopter Textron, Inc. Model
204B, 205A, 205A-1, 205B, 212, and 412 Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to Bell Helicopter Textron, Inc. (BHTI) Model 205B,
212, and 412 helicopters, that currently requires a repetitive magnetic
particle inspection of the main transmission lower planetary spider.
This amendment expands the applicability to include the BHTI Model
204B, 205A, and 205A-1 helicopters. This amendment is prompted by the
need to apply the magnetic particle inspections required by that AD to
additional BHTI model helicopters, as well as more clearly state the
applicable compliance times for these inspections. The actions
specified by this AD are intended to prevent a fatigue failure of the
main transmission lower planetary spider, which could result in failure
of the main transmission, and subsequent loss of control of the
helicopter.
EFFECTIVE DATE: July 29, 1994.
ADDRESSES: This AD and any related information may be examined in the
Rules Docket at the Federal Aviation Administration, Office of the
Assistant Chief Counsel, 2601 Meacham Blvd., Room 663, Fort Worth,
Texas.
FOR FURTHER INFORMATION CONTACT: Mr. Uday Garadi, Aerospace Engineer,
Rotorcraft Directorate, Rotorcraft Certification Office, ASW-170, 2601
Meacham Boulevard, Fort Worth, Texas 76193-0170, telephone (817) 222-
5157, fax (817) 222-5959.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations by superseding AD 92-11-07, Amendment 39-8257 (57
FR 30392, July 9, 1992), which is applicable to Bell Helicopter
Textron, Inc. (BHTI) Model 205B, 212, and 412 helicopters, was
published in the Federal Register on March 23, 1993 (58 FR 15444). That
action proposed to apply the current requirements for a repetitive
magnetic particle inspection (MPI) of the main transmission lower
planetary spider (spider), part number (P/N) 204-040-785-003, to BHTI
Model 204B, 205A, and 205A-1 helicopters.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
One comment was received. The commenter states that a 3,100 hours'
time-in-service MPI interval is redundant for the Model 204B since an
MPI is required at overhaul. The FAA does not agree. An MPI is not
required at overhaul for all operators. The manufacturer's overhaul
time and associated inspection requirements are mandatory only for
those operators whose maintenance program is based on the BHTI program.
Therefore, this is not a redundant requirement for those operators who
do not perform their overhauls in accordance with the manufacturer's
suggestions.
The same commenter states that BHTI Models 204B and 205A-1 should
not be included in the AD because the torque applied to the spider when
installed in the Models 204B and 205A-1 is lower than when the spider
is installed in the Models 212 and 412. The FAA does not concur with
this comment. Since parts can be swapped from Models 212 and 412 with
higher torque or power requirements to the Models 204B and 205A-1 with
lower torque requirements, the FAA concludes that the required MPI is
essential for safety.
This commenter also states that the Models 205A and 205A-1 have
different transmission overhaul intervals than the Model 212 and 412
helicopters and indicates that this AD inspection interval should
consider these different overhaul intervals. The FAA has considered
this in arriving at the MPI inspection interval. The MPI interval of
3,100 hours' time-in-service is based on the amount of time it takes a
crack to propagate from initiation to failure under typical flight
conditions and is also compatible with typical overhaul intervals. The
MPI interval of 3,100 hours' time-in-service will provide for crack
detection before failure without imposing an undue burden on operators.
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule as proposed, except for
editorial and address changes. The FAA has determined that these
changes will neither increase the economic burden on any operator nor
increase the scope of the AD.
The FAA estimates that 1,207 helicopters of U.S. registry will be
affected by this AD, that it will take approximately 6 work hours per
helicopter if performed during transmission overhaul, or 32 work hours
if not performed during overhaul, to accomplish the required actions,
and that the average labor rate is $55 per work hour. It is estimated
that one-half of the affected helicopter fleet may be affected each
year by the requirements of this AD. Based on these figures, the total
cost impact of the AD on U.S. operators is estimated to range from
$199,155 to $1,062,160.
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.
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) 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 final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it 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. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing Amendment 39-8257 (57 FR
30392, July 9, 1992) and by adding a new airworthiness directive (AD),
Amendment 39-8683, to read as follows:
AD 93-17-12 Bell Helicopter Textron, Inc. (BHTI): Amendment 39-8683.
Docket No. 92-ASW-49. Supersedes AD 92-11-07, Amendment 39-8257.
Applicability: Model 204B, 205A, 205A-1, 205B, 212, and 412
helicopters, with main rotor transmission lower planetary spider
(spider), part number (P/N) 204-040-785-003, installed, certificated
in any category.
Compliance: Required as indicated, unless accomplished
previously.
To prevent fatigue failure of the spider, which could result in
failure of the main transmission and subsequent loss of control of
the helicopter, accomplish the following:
(a) Within the next 600 hours' time-in-service (TIS) after the
effective date of this AD, unless previously accomplished within the
last 2,500 hours' TIS, and thereafter at intervals not to exceed
3,100 hours' TIS from the last magnetic particle inspection (MPI),
remove the spider and perform an MPI for cracks in accordance with
the pertinent BHTI maintenance, repair, and overhaul manuals.
(b) Replace any cracked spider with an airworthy part prior to
further flight.
(c) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used when 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: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Manager, Rotorcraft Certification Office.
(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 helicopter to a location where
the requirements of this AD can be accomplished.
(e) This amendment becomes effective on July 29, 1994.
Issued in Fort Worth, Texas, on May 13, 1994.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 94-15408 Filed 6-23-94; 8:45 am]
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