[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 /
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[[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]
BILLING CODE 4910-13-P