[Federal Register Volume 59, Number 3 (Wednesday, January 5, 1994)]
[Proposed Rules]
[Pages 556-558]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-143]


[[Page Unknown]]

[Federal Register: January 5, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-SW-20-AD]

 

Airworthiness Directives; Bell Helicopter Textron, Inc. Model 
214B, 214B-1, and 214ST Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to Bell Helicopter Textron, Inc. 
Model 214B, 214B-1, and 214ST helicopters. This proposal would 
establish a mandatory retirement life of 60,000 high-power events for 
the main rotor trunnion (trunnion), which is currently not a life-
limited part. This proposal is prompted by the manufacturer's analysis 
and retesting that has shown that the trunnion is sensitive to high-
power events. The actions specified by the proposed AD are intended to 
prevent fatigue failure of the trunnion, that could result in loss of 
the main rotor and subsequent loss of control of the helicopter.

DATES: Comments must be received by February 22, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Assistant Chief Counsel, Attention: 
Rules Docket No. 93-SW-20-AD, 4400 Blue Mound Road, bldg 3B, room 158, 
Fort Worth, Texas 76106. Comments may be inspected at this location 
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal 
holidays.

FOR FURTHER INFORMATION CONTACT: Mr. Scott Horn, Aerospace Engineer, 
Rotorcraft Certification Office, FAA, Rotorcraft Directorate, ASW-170, 
Fort Worth, Texas 76193-0170, telephone (817) 624-5177, fax (817) 740-
3394.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 93-SW-20-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Office of the Assistant Chief Counsel, Attention: Rules 
Docket No. 93-SW-20-AD, 4400 Blue Mound Road, bldg. 3B, room 158, Fort 
Worth, Texas 76106.

Discussion

    This document proposes to adopt a new airworthiness directive (AD) 
that is applicable to Bell Helicopter Textron, Inc. Model 214B, 214B-1, 
and 214ST helicopters. Recent retesting and analysis has shown that the 
main rotor trunnion (trunnion), part number 214-010-230-101, is 
sensitive to high-power events. High power events are takeoffs and 
external load lifts. This condition, if not corrected, could result in 
fatigue failure of the trunnion, loss of the main rotor, and subsequent 
loss of the control of the helicopter.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require for the trunnion, within the next 25 hours' 
time-in-service after the effective date of this AD, (1) creation of a 
component history card; (2) accumulation of the historical high-power 
events; and (3) thereafter, recording of the high-power events as they 
occur. Additionally, the proposed AD would establish a trunnion 
retirement life of 60,000 high-power events.
    The FAA estimates that 15 helicopters of U.S. registry would be 
affected by this proposed AD, that it would take approximately 16 work 
hours per helicopter to accomplish the proposed actions, and that the 
average labor rate is $55 per work hour. Required parts would cost 
approximately $10,929 per helicopter. Based on these figures, the total 
cost impact of the proposed AD on U.S. operators is estimated to be 
$29,523, assuming inspection and modification of one-sixth of the fleet 
is required each year.
    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting 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.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 14 
CFR part 39 of the Federal Aviation Regulations 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 adding the following new 
airworthiness directive:

Bell Helicopter Textron, Inc.: Docket No. 93-SW-20-AD.
    Applicability: Model 214B, 214B-1, and 214ST helicopters, 
equipped with main rotor trunnion (trunnion), part number 214-010-
230-101, certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent fatigue failure of the trunnion as a result of 
takeoffs and external loads lifts (high-power events), that could 
result in loss of the main rotor and subsequent loss of control of 
the helicopter, accomplish the following:
    (a) Within the next 25 hours' time-in-service after the 
effective date of this airworthiness directive (AD), accomplish the 
following:
    (1) Create a historical service record or component history card 
for the trunnion.
    (2) Determine the actual time-in-service of the trunnion from 
maintenance records, if possible. If the actual time-in-service 
cannot be determined, use a time-in-service of 900 hours per year. 
Prorate the hours for a partial year.
    (3) For Model 214B and 214B-1 helicopters, determine and record 
the accumulated high-power events on the trunnion as follows:
    (i) If the number of high-power events is unknown, assign 12 
high-power events for each hour time-in-service obtained in 
accordance with paragraph (a)(2).
    (ii) If the number of high-power events is known, divide that 
number by 2 and record the resulting number as the total accumulated 
high-power events.
    (4) For Model 214ST helicopters, determine and record the 
accumulated high-power events on the trunnion as follows:
    (i) If the number of events is unknown, assign 11 high-power 
events for each hour time-in-service obtained in accordance with 
paragraph (a)(2).
    (ii) If the number of high-power events is known, record that 
number as the total accumulated high-power events.
    (b) After the effective date of this AD, continue to record 
high-power events in the aircraft maintenance record. For Model 214B 
and 214B-1 helicopters, divide the number of high-power events by 2 
and add the resulting number to the previously recorded sum. For 
Model 214ST helicopters, add the high-power events to the previously 
recorded sum.
    (c) Remove the trunnion and replace it with an airworthy 
trunnion in accordance with the following:
    (1) For each trunnion with 59,400 or more high-power events on 
the effective date of this AD, remove and replace the trunnion on or 
before the accumulation of an additional 600 high-power events.
    (2) For each trunnion with less than 59,400 high-power events on 
the effective date of this AD, remove and replace the trunnion on or 
before attaining 60,000 high-power events.
    (d) This AD revises the helicopter Airworthiness Limitations 
Section of the maintenance manual by establishing a new retirement 
life for the trunnion.
    (e) An alternative method of compliance or adjustment of the 
compliance time, which provides an acceptable level of safety, may 
be used when approved by the Manager, Rotorcraft Certification 
Office, FAA, Rotorcraft Directorate, Fort Worth, Texas 76193-0170. 
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 Rotorcraft Certification Office.

    (f) Special flight permits may be issued in accordance with FAR 
21.197 and 21.199 to operate the helicopter to a location where the 
requirements of this AD can be accomplished.
    Issued in Fort Worth, Texas, on November 5, 1993.
Larry M. Kelly,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 94-143 Filed 1-4-94; 8:45 am]
BILLING CODE 4910-13-P