AD Amdt-39-10152

[Federal Register Volume 62, Number 196 (Thursday, October 9, 1997)]
[Rules and Regulations]
[Pages 52653-52655]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 97-26623]



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Federal Register / Vol. 62, No. 196 / Thursday, October 9, 1997 / 
Rules and Regulations

[[Page 52653]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-SW-24-AD; Amendment 39-10152; AD 97-15-16]
RIN 2120-AA64


Airworthiness Directives; Bell Helicopter Textron Canada (BHTC) 
Model 430 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment 
adopting Airworthiness Directive (AD) 97-15-16, which was sent 
previously to all known U.S. owners and operators of BHTC Model 430 
helicopters by individual letters. This AD requires inspections of all 
4 main rotor adapter assemblies for evidence of flapping contact 
between the adapter liners and the upper stop assembly plugs, and for 
evidence of lead-lag contact between the adapter pads and the yoke 
assembly; installing a never-exceed-velocity (VNE) placard; marking the 
airspeed indicator to reflect the airspeed restriction; installing a 
slippage mark on the airspeed indicator glass and instrument case; and 
inserting revisions to the rotorcraft flight manual to reflect the 
airspeed revision. This amendment is prompted by a report of a main 
rotor tip path plane separation, which occurred during a ferry flight 
at an airspeed of more than 140 knots indicated airspeed (KIAS). The 
actions specified by this AD are intended to prevent tip path plane 
separation, increased vibrations, possible damage to the main rotor 
system, and subsequent loss of control of the helicopter.

DATES: Effective October 24, 1997, to all persons except those persons 
to whom it was made immediately effective by priority letter AD 97-15-
16, issued on July 18, 1997, which contained the requirements of this 
amendment.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 24, 1997.
    Comments for inclusion in the Rules Docket must be received on or 
before December 8, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Assistant Chief Counsel, Attention: 
Rules Docket No. 97-SW-24-AD, 2601 Meacham Blvd., Room 663, Fort Worth, 
Texas 76137.
    The applicable service information may be obtained from Bell 
Helicopter Textron Canada, 12,800 Rue de l'Avenir, Mirabel, Quebec 
JON1LO, telephone (800) 463-3036, fax (514) 433-0272. This information 
may be examined at the FAA, Office of the Assistant Chief Counsel, 2601 
Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, Washington, 
DC.

FOR FURTHER INFORMATION CONTACT: Mr. 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: On July 18, 1997, the FAA issued priority 
letter AD 97-15-16, applicable to BHTC Model 430 helicopters, which 
requires inspections of all 4 main rotor adapter assemblies for 
evidence of flapping contact between the adapter liners and the upper 
stop assembly plugs, and for evidence of lead-lag contact between the 
adapter pads and the yoke assembly; installing a VNE placard; marking 
the airspeed indicator to reflect the airspeed restriction; installing 
a slippage mark on the airspeed indicator glass and instrument case; 
and inserting revisions to the rotorcraft flight manual to reflect the 
airspeed revision. That action was prompted by one report of a main 
rotor tip path plane separation, which occurred during a ferry flight 
at an airspeed of more than 140 KIAS. The separation was observed from 
the cockpit and caused a vibration at a frequency near one per 
revolution. BHTC was able to reproduce a similar event on other Model 
430 helicopters, and determined that the separation may occur at 
airspeeds above 120 KIAS. Therefore, flight at airspeeds above 120 KIAS 
is considered unsafe. This condition, if not corrected, could result in 
tip path plane separation, increased vibrations, possible damage to the 
main rotor system, and subsequent loss of control of the helicopter.
    The FAA has reviewed Bell Helicopter Textron Alert Service Bulletin 
(ASB) No. 430-97-2, dated July 11, 1997, which describes inspections of 
all 4 main rotor adapter assemblies for evidence of flapping contact 
between the adapter liners and the upper stop assembly plugs; and, for 
evidence of lead-lag contact between the adapter pads and the yoke 
assembly. The ASB also describes further inspections if evidence of 
contact is found during either of those inspections. For helicopters 
equipped with skid landing gear, removing the existing VNE placard and 
installing a VNE placard, part number (P/N) 430-075-208-107, is 
required; and for helicopters equipped with retractable landing gear, 
removing the existing VNE placard and installing a VNE placard, P/N 
430-075-208-109, is required. Finally, the ASB describes marking the 
airspeed indicators to reflect the airspeed restriction by adding to 
the instrument glass a red arc to indicate that airspeeds above 120 
KIAS are prohibited; and inserting revisions to the rotorcraft flight 
manual that reflect this airspeed restriction.
    Since the unsafe condition described is likely to exist or develop 
on other BHTC Model 430 helicopters of the same type design, the FAA 
issued priority letter AD 97-15-16 to prevent tip path plane 
separation, increased vibrations, possible damage to the main rotor 
system, and subsequent loss of control of the helicopter. The AD 
requires, before further flight, inspections of all 4 main rotor 
adapter assemblies for evidence of flapping contact between the adapter 
liners and the upper stop assembly plugs, and for evidence of lead-lag 
contact between the adapter pads and the yoke assembly. Flapping 
contact is indicated by scrubbing (or smudging) of the adapter liner 
surface, characteristic of relative motion between the surfaces of the 
adapter liners and upper stop assembly plugs. Lead-lag contact is 
indicated by

[[Page 52654]]

a permanent indentation or split in the surface of the adapter pads. 
Further inspections are required if evidence of contact is found during 
either of those inspections. For helicopters equipped with skid landing 
gear, this AD requires the removing the existing VNE placard and 
installing a VNE placard, P/N 430-075-208-107; and for helicopters 
equipped with retractable landing gear, removing the existing VNE 
placard and installing a VNE placard, P/N 430-075-208-109, is required. 
Finally, this AD requires marking each airspeed indicator to reflect 
the airspeed restriction by adding to the instrument glass a red arc to 
indicate that airspeeds above 120 KIAS are prohibited; installing a 
slippage mark on each airspeed indicator glass and instrument case; and 
inserting revisions to the rotorcraft flight manual that reflect the 
airspeed restriction. The actions are required to be accomplished in 
accordance with the service bulletin described previously.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment thereon were 
impracticable and contrary to the public interest, and good cause 
existed to make the AD effective immediately by individual letters 
issued on July 18, 1997 to all known U.S. owners and operators of BHTC 
Model 430 helicopters. These conditions still exist, and the AD is 
hereby published in the Federal Register as an amendment to Sec. 39.13 
of the Federal Aviation Regulations (14 CFR 39.13) to make it effective 
to all persons.

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 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 concernedwith 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. 97-SW-24-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, Incorporation by 
reference, 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:


97-15-16  Bell Helicopter Textron Canada: Amendment 39-10152. Docket 
No. 97-SW-24-AD.

    Applicability: Model 430 helicopters, 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 (g) 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 before further flight, unless accomplished 
previously.
    To prevent tip path plane separation, increased vibrations, 
possible damage to the main rotor system, and subsequent loss of 
control of the helicopter, accomplish the following:
    (a) Inspect all 4 main rotor adapter assemblies for evidence of 
flapping contact between the adapter liners and the upper stop 
assembly plugs. Refer to Figures 1, 2, and 3 of the Accomplishment 
Instructions of Bell Helicopter
    Textron Canada (BHTC) Alert Service Bulletin (ASB) No. 430-97-2, 
dated July 11, 1997. Flapping contact is indicated by scrubbing (or 
smudging) of the adapter liner surface, characteristic of relative 
motion between the surfaces of the adapter lines and upper stop 
assembly plugs.
    (b) Inspect all 4 main rotor adapter assemblies for evidence of 
lead-lag contact between the adapter pads and the yoke assembly. 
Refer to Figures 1 and 2 of the Accomplishment Instructions of BHTC 
ASB No. 430-97-2, dated July 11, 1997. Lead-lag contact is indicated 
by a permanent indentation or split in the surface of the adapter 
pads.
    (c) If the inspections in paragraphs (a) or (b) of this AD 
reveal that there has been contact, inspect and replace the main 
rotor yoke and stop assemblies in accordance with Part I, No. 3 of 
the Accomplishment Instructions of BHTC ASB No. 430-97-2, dated July 
11, 1997.
    (d) For helicopters equipped with skid landing gear or 
retractable landing gear,

[[Page 52655]]

remove the existing never-exceed-velocity (VNE) placard from the 
overhead console and install VNE placard, P/N 430-075-208-107, or P/
N 430-075-208-109, as applicable, in accordance with Part II, of the 
Accomplishment Instructions of BHTC ASB No. 430-97-2, dated July 11, 
1997.
    (e) Install on each airspeed indicator a red arc between 120 
knots and 150 knots to indicate that airspeeds above 120 knots 
indicated airspeed are prohibited. Install a slippage mark on each 
airspeed indicator glass and instrument case.
    (f) Insert the temporary revisions, BHT-430-FM-1 and BHT-430-
FMS-1, as appropriate, both dated July 7, 1997, into the rotorcraft 
flight manual.
    (g) 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, 
Rotorcraft Directorate, FAA. 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Rotorcraft Certification Office.

    (h) Special flight permits will not be issued.
    (i) The inspections and installations shall be done in 
accordance with Bell Helicopter Textron Alert Service Bulletin (ASB) 
No. 430-97-2, dated July 11, 1997. This incorporation by reference 
was approved by the Director of the Federal Register in accordance 
with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from 
Bell Helicopter Textron Canada, 12,800 Rue de l'Avenir, Mirabel, 
Quebec JON1LO, telephone (800) 463-3036, fax (514) 433-0272. Copies 
may be inspected at the FAA, Office of the Assistant Chief Counsel, 
2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.
    (j) This amendment becomes effective on October 24, 1997, to all 
persons except those persons to whom it was made immediately 
effective by priority letter AD 97-15-16, issued July 18, 1997, 
which contained the requirements of this amendment.

    Issued in Fort Worth, Texas, on September 26, 1997.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 97-26623 Filed 10-8-97; 8:45 am]
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