[Federal Register Volume 62, Number 48 (Wednesday, March 12, 1997)]
[Rules and Regulations]
[Pages 11320-11321]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-6089]



[[Page 11320]]

-----------------------------------------------------------------------


DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-SW-25-AD; Amendment 39-9960; AD 97-06-03]
RIN 2120-AA64


Airworthiness Directives; Bell Helicopter Textron, Inc. (BHTI) 
Model 214ST Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to Bell Helicopter Textron, Inc. (BHTI) Model 214ST 
helicopters, that currently establishes a mandatory retirement life of 
50,000 high-power events for the main rotor mast (mast). This amendment 
requires changing the retirement life for the mast from high-power 
events to a maximum accumulated Retirement Index Number (RIN) of 
140,000 and applying this RIN to an additional part-numbered mast. This 
amendment is prompted by fatigue analyses and tests that show certain 
masts fail sooner than originally anticipated because of an 
unanticipated high number of takeoffs and external load lifts in 
addition to the deterioration in strength that occurs under other 
operating conditions. The actions specified by this AD are intended to 
prevent fatigue failure of the mast, which could result in failure of 
the main rotor system and subsequent loss of control of the helicopter.

EFFECTIVE DATE: April 16, 1997.

FOR FURTHER INFORMATION CONTACT: Mr. Uday Garadi, Aerospace Engineer, 
FAA, Rotorcraft Certification Office, Rotorcraft Directorate, 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 (14 CFR part 39) by superseding AD 94-15-04, 
Amendment 39-8975 (59 FR 37155, July 21, 1994), which is applicable to 
BHTI Model 214ST helicopters, was published in the Federal Register on 
November 14, 1996 (61 FR 58356). That action proposed to require 
creation of a component history card or equivalent record on which to 
record RIN counts, and to establish a retirement life of a maximum 
accumulated RIN for the mast of 140,000.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the 
proposal or the FAA's determination of the cost to the public. The FAA 
has determined that air safety and the public interest require the 
adoption of the rule as proposed.
    The FAA estimates that nine helicopters of U.S. registry will be 
affected by this AD, that it will take approximately (1) 48 work hours 
per helicopter to replace the mast; (2) 2 work hours per helicopter to 
create the component history card or equivalent record (record); and 
(3) 10 work hours per helicopter to maintain the record each year, and 
that the average labor rate is $60 per work hour. Required parts will 
cost approximately $17,267 per mast. Based on these figures, the total 
cost impact of the proposed AD on U.S. operators is estimated to be 
$36,700 for the first year and $35,800 for each subsequent year. These 
costs assume replacement of the mast in one-sixth of the fleet each 
year, creation and maintenance of the records for all the fleet the 
first year, and creation of one-sixth of the fleet's records and 
maintenance of the records for all the fleet each subsequent year.
    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 USC 106(g), 40113, 44701.


Sec. 39.13   [Amended]

    2. Section 39.13 is amended by removing Amendment 39-8975 (59 FR 
37155), and by adding a new airworthiness directive (AD), Amendment 39-
9960, to read as follows:

AD 97-06-03  Bell Helicopter Textron, Inc. (BHTI): Amendment 39-
9960. Docket No. 94-SW-25-AD. Supersedes AD 94-15-04, Amendment 39-
8975.

    Applicability: Model 214ST helicopter with main rotor mast 
(mast), part number (P/N) 214-040-090-109 or P/N 214-040-090-121, 
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 
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 use the authority 
provided in paragraph (e) to request approval from the FAA. This 
approval may address either no action, if the current configuration 
eliminates the unsafe condition, or different actions necessary to 
address the unsafe condition described in this AD. Such a request 
should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any helicopter from the applicability of this AD.

    Compliance: Required within 25 hours time-in-service (TIS) after 
the effective date of this AD, unless accomplished previously.
    To prevent fatigue failure of the mast, which could result in 
failure of the main rotor system and subsequent loss of control of 
the helicopter, accomplish the following:
    (a) Create a component history card or an equivalent record for 
the affected mast.
    (b) Determine and record the accumulated Retirement Index Number 
(RIN) to date on the mast as follows:
    (1) For operators with mast, P/N 214-040-090-109, multiply the 
takeoffs and external load lifts (high-power events) total to date 
by 2.8 (round up the result to the next whole number).
    (2) For operators with mast, P/N 214-040-090-121, multiply the 
factored flight hour total to date by 14 (round up the result to the 
next whole number).
    (3) Record on the component history card the accumulated RIN.

    Note 2: BHTI Alert Service Bulletin (ASB) No. 214ST-94-67, dated 
November 7, 1994, pertains to this subject.

    (c) After complying with paragraphs (a) and (b) of this AD, 
during each operation thereafter, maintain a count of the number and 
type of external load lifts and the

[[Page 11321]]

number of takeoffs performed, and at the end of each day's 
operations, increase the accumulated RIN on the component history 
card as follows:
    (1) Increase the RIN by 2 for each takeoff.
    (2) Increase the RIN by 2 for each external load lift operation; 
or, increase the RIN by 4 for each external load lift operation in 
which the load is picked up at a higher elevation and released at a 
lower elevation, and the difference in elevation between the pickup 
point and the release point is 200 feet or greater.
    (d) Remove the mast, P/N 214-040-090-109 or -121, from service 
on or before attaining an accumulated RIN of 140,000. The mast is no 
longer retired based upon flight hours. This AD revises the 
Airworthiness Limitations Section of the maintenance manual by 
establishing a new retirement life for the mast of 140,000 RIN.
    (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, 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.

    (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 helicopter to a location where 
the requirements of this AD can be accomplished.
    (g) This amendment becomes effective on April 16, 1997.

    Issued in Fort Worth, Texas, on February 26, 1997.
Larry M. Kelly,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 97-6089 Filed 3-11-97; 8:45 am]
BILLING CODE 4910-13-U