Document ID: FAA-2021-0951-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Various Model 234 and Model CH-47D Helicopters
Posted Date: 2021-12-20T05:00Z

[Federal Register Volume 86, Number 241 (Monday, December 20, 2021)]
[Rules and Regulations]
[Pages 71820-71823]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-27539]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0951; Project Identifier AD-2021-01047-R; 
Amendment 39-21804; AD 2021-23-06]
RIN 2120-AA64

Airworthiness Directives; Various Model 234 and Model CH-47D 
Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
various Model 234 and Model CH-47D helicopters. This AD was prompted by 
two reports of mechanical failures of the longitudinal cyclic trim 
actuator (LCTA). This AD requires determining the maintenance history, 
and hours time-in-service (TIS) and number of lift cycles for each LCTA 
since last overhaul, and then requires initial and repetitive overhauls 
of each LCTA based on that maintenance and service history. This AD 
also prohibits installing an LCTA unless it meets certain requirements. 
Finally, this AD requires reporting certain information to the FAA. The 
FAA is issuing this AD to address the unsafe condition on these 
products.

DATES: This AD is effective January 4, 2022.
    The FAA must receive comments on this AD by February 3, 2022.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0951; or in person at 
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The AD docket contains this final rule, any 
comments received, and other information. The street address for the 
Docket Operations is listed above.

FOR FURTHER INFORMATION CONTACT: David Herron, Aerospace Engineer, 
Systems & Equipment Section, Seattle ACO Branch, FAA, 2200 South 216th 
St., Des Moines, WA 98198; phone and fax: (206) 231-3554; email 
[email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA received two reports of mechanical failure of an LCTA, the 
function of which is to constrain and control the non-rotating 
swashplate. In both failures, which occurred on Model CH-47D 
helicopters, the flight crew was forced to make an emergency landing as 
they had difficulty controlling the helicopter. Model 234 and Model CH-
47D helicopters both have the same LCTA installed, with two installed 
on each rotorcraft. Investigation as to the root cause of these 
failures has determined that inadequate maintenance overhaul procedures 
and scheduled overhaul intervals for this critical flight component 
with a single structural load path likely contributed to this unsafe 
condition. One event occurred due to excessive wear of the acme screw 
threads from degradation or lack of lubrication. The other event was 
due to metal fatigue leading to the fracture of the fourth stage spur 
gear shaft (part of the acme screw) caused by repetitive abnormal 
loading. The repetitive abnormal loading occurred because of the 
incorrect installation of a travel limit switch, which rendered the 
switch ineffective in removing power from the electric motor at the 
designed travel limit, thus allowing the electric motor to repetitively 
overstroke the actuator into a mechanical stop. While the failure modes 
were different, the failure effects were the same: Loss of the 
constraint and control normally provided by the LCTA. Failure of the 
LCTA, if not prevented, could result in loss of control of the rotor 
blades and subsequent loss of control of the helicopter or the rotor 
blades striking the fuselage. The FAA is issuing this AD to address the 
unsafe condition on these products.
    The type certificate (TC) holder for Model 234 helicopters is 
Columbia Helicopters Inc. (TC previously held by Boeing Defense & Space 
Group), and the TC holders for Model CH-47D helicopters currently 
include Columbia Helicopters, Inc., Billings Flying Service, Inc., 
Tandem Rotor, LLC, and Unical Aviation, Inc. (originally

[[Page 71821]]

manufactured for military use). The FAA did not limit this AD to these 
TC holders because the FAA expects that additional TC holders of 
helicopters are subject to this same unsafe condition.

FAA's Determination

    The FAA is issuing this AD because the agency has determined the 
unsafe condition described previously is likely to exist or develop in 
other products of the same type design.

AD Requirements

    This AD requires, within 3 calendar days after the effective date 
of the AD, determining the hours TIS and lift cycles since last 
overhaul for each LCTA. If LCTA lift cycles cannot be determined, 
counting 6 lift cycles for each hour TIS is required. For purposes of 
this AD, a lift cycle is defined as takeoff from ground for flight, a 
lift of a new external load while in flight, or a lift of a new 
internal load while in flight (e.g., fluid drawn into an internal 
tank).
    If the last LCTA overhaul was not approved for return to service by 
a person that meets the requirements of 14 CFR part 43, or, if you are 
unable to establish hours TIS and lift cycles since last overhaul of an 
LCTA (e.g., hours TIS and lift cycles for each LCTA were not tracked), 
this AD requires, within 10 calendar days after the effective date of 
the AD, and thereafter at intervals not to exceed 3,000 hours TIS or 
18,000 lift cycles, whichever occurs first, overhauling that LCTA. For 
purposes of any overhaul required by this AD, the overhaul must include 
an inspection of each acme screw for wear and cracking, lubricating all 
drive threads and gears, and a test to ensure proper operation of the 
extend and retract travel limit switches.
    If the last LCTA overhaul was approved for return to service by a 
person that meets the requirements of 14 CFR part 43, overhauling the 
LCTA as described in this AD is required within 500 hours TIS or 3,000 
lift cycles since last overhaul, whichever occurs first; or within 90 
days after the effective date of the AD, whichever occurs later. 
Thereafter, overhauling each LCTA at intervals not to exceed 3,000 
hours TIS or 18,000 lift cycles, whichever occurs first, is required.
    This AD also prohibits, as of the AD's effective date, installing 
any LCTA on any helicopter unless it has been approved for return to 
service by a person that meets the requirements of 14 CFR part 43 after 
an overhaul as described in this AD, and that LCTA has not been in 
service for more than 3,000 hours TIS or 18,000 lift cycles since that 
overhaul. Finally, this AD requires, within 10 calendar days after 
completing each LCTA overhaul required by this AD, reporting certain 
information to the FAA.

Interim Action

    The FAA considers this AD to be an interim action. The FAA is 
currently considering requiring overhaul of the LCTA at different time 
intervals or takeoff and lift cycles. However, the planned compliance 
time for those actions would allow enough time to provide notice and 
opportunity for prior public comment on the merits of those actions. 
Additionally, the inspection reports that are required by this AD will 
enable the FAA to obtain better insight into the cause of the unsafe 
condition and to eventually develop final action to address the unsafe 
condition. Once final action has been identified, the FAA might 
consider further rulemaking.

Justification for Immediate Adoption and Determination of the Effective 
Date

    Section 553(b)(3)(B) of the Administrative Procedure Act (APA) (5 
U.S.C. 551 et seq.) authorizes agencies to dispense with notice and 
comment procedures for rules when the agency, for ``good cause,'' finds 
that those procedures are ``impracticable, unnecessary, or contrary to 
the public interest.'' Under this section, an agency, upon finding good 
cause, may issue a final rule without providing notice and seeking 
comment prior to issuance. Further, section 553(d) of the APA 
authorizes agencies to make rules effective in less than thirty days, 
upon a finding of good cause.
    An unsafe condition exists that requires the immediate adoption of 
this AD without providing an opportunity for public comments prior to 
adoption. The FAA has found that the risk to the flying public 
justifies foregoing notice and comment prior to adoption of this rule 
because the LCTAs are critical flight control components with design 
elements that must be properly and regularly maintained to ensure 
continued safe flight of the identified rotorcraft. The two reported 
in-service events evidence a deficiency in the maintenance of the LCTAs 
that must be resolved. Additionally, the compliance time for some of 
the required actions is within 3 calendar days after the effective date 
of this AD, which is shorter than the time necessary for the public to 
comment and for publication of the final rule. Accordingly, notice and 
opportunity for prior public comment are impracticable and contrary to 
the public interest pursuant to 5 U.S.C. 553(b)(3)(B).
    In addition, the FAA finds that good cause exists pursuant to 5 
U.S.C. 553(d) for making this amendment effective in less than 30 days, 
for the same reasons the FAA found good cause to forego notice and 
comment.

Comments Invited

    The FAA invites you to send any written data, views, or arguments 
about this final rule. Send your comments to an address listed under 
ADDRESSES. Include ``Docket No. FAA-2021-0951 and Project Identifier 
AD-2021-01047-R'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the final rule, explain the 
reason for any recommended change, and include supporting data. The FAA 
will consider all comments received by the closing date and may amend 
this final rule because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
https://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this final rule.

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this AD contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this AD, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this AD. Submissions containing CBI should be sent to David 
Herron, Aerospace Engineer, Systems & Equipment Section, Seattle ACO 
Branch, FAA, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 
(206) 231-3554; email [email protected]. Any commentary that the FAA 
receives which is not specifically designated as CBI will be placed in 
the public docket for this rulemaking.

Regulatory Flexibility Act

    The requirements of the Regulatory Flexibility Act (RFA) do not 
apply when

[[Page 71822]]

an agency finds good cause pursuant to 5 U.S.C. 553 to adopt a rule 
without prior notice and comment. Because FAA has determined that it 
has good cause to adopt this rule without prior notice and comment, RFA 
analysis is not required.

Costs of Compliance

    The FAA estimates that this AD affects 74 helicopters of U.S. 
Registry. Labor rates are estimated at $85 per work-hour. Based on 
these numbers, the FAA estimates the following costs to comply with 
this AD.
    Removing and reinstalling both LCTAs on each helicopter will take 
about 4 work-hours, with no parts costs, for an estimated cost of about 
$340 per helicopter or $25,160 for the U.S. fleet.
    Overhauling both LCTAs on each helicopter will take about 56 work-
hours, and parts costs will be about $200, for an estimated cost of 
about $4,960 per overhaul.
    Reporting information to the FAA will take about 1 work hour per 
helicopter, for an estimated cost of about $85 per report.

Paperwork Reduction Act

    A federal agency may not conduct or sponsor, and a person is not 
required to respond to, nor shall a person be subject to a penalty for 
failure to comply with a collection of information subject to the 
requirements of the Paperwork Reduction Act unless that collection of 
information displays a currently valid OMB Control Number. The OMB 
Control Number for this information collection is 2120-0056. Public 
reporting for this collection of information is estimated to be 
approximately 1 hour per response, including the time for reviewing 
instructions, searching existing data sources, gathering and 
maintaining the data needed, and completing and reviewing the 
collection of information. All responses to this collection of 
information are mandatory. Send comments regarding this burden estimate 
or any other aspect of this collection of information, including 
suggestions for reducing this burden to: Information Collection 
Clearance Officer, Federal Aviation Administration, 10101 Hillwood 
Parkway, Fort Worth, TX 76177-1524.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII: Aviation Programs 
describes in more detail the scope of the Agency's authority.
    The FAA is issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701: General requirements. 
Under that section, Congress charges the FAA with promoting safe flight 
of civil aircraft in air commerce by prescribing regulations for 
practices, methods, and procedures the Administrator finds necessary 
for safety in air commerce. This regulation is within the scope of that 
authority because it addresses an unsafe condition that is likely to 
exist or develop on products identified in this rulemaking action.

Regulatory Findings

    This AD will not have federalism implications under Executive Order 
13132. This AD will not have a substantial direct effect 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.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866, and
    (2) Will not affect intrastate aviation in Alaska.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2021-23-06 Various Model 234 and Model CH-47D Helicopters: Amendment 
39-21804; Docket No. FAA-2021-0951; Project Identifier AD-2021-
01047-R.

(a) Effective Date

    This airworthiness directive (AD) is effective January 4, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Model 234 and Model CH-47D helicopters, 
regardless of type certificate holder, certificated in any category. 
Type certificate holders include, but are not limited to:
    (1) Columbia Helicopters, Inc.,
    (2) Billings Flying Service, Inc.,
    (3) Tandem Rotor, LLC, and
    (4) Unical Aviation, Inc.

(d) Subject

    Joint Aircraft System Component (JASC) Code/Air Transport 
Association (ATA) of America Code: 6710, Rotor flight controls.

(e) Unsafe Condition

    This AD was prompted by inadequate maintenance, which resulted 
in mechanical failure of the longitudinal cyclic trim actuator 
(LCTA). The FAA is issuing this AD to correct this unsafe condition, 
which if not addressed, could result in loss of control of the rotor 
blades and subsequent loss of control of the helicopter or the rotor 
blades striking the fuselage.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    (1) Within 3 calendar days after the effective date of this AD, 
determine the hours time-in-service (TIS) and lift cycles since last 
overhaul for each LCTA on your helicopter. If lift cycles cannot be 
determined, count 6 lift cycles for each hour TIS for each LCTA. For 
purposes of this AD, a lift cycle is defined as any of the 
following:
    (i) Takeoff from ground for flight;
    (ii) Lift of a new external load while in flight; or
    (iii) Lift of a new internal load while in flight (e.g., fluid 
drawn into an internal tank).
    (2) If the last overhaul of any LCTA was not approved for return 
to service by a person that meets the requirements of 14 CFR part 
43, or, if you are unable to establish hours TIS and lift cycles 
since last overhaul of an LCTA (e.g., hours TIS and lift cycles for 
each LCTA were not tracked), within 10 calendar days after the 
effective date of this AD, and thereafter at intervals not to exceed 
3,000 hours TIS or 18,000 lift cycles, whichever occurs first, 
overhaul that LCTA. For purposes of any overhaul required by this 
AD, the overhaul must include:
    (i) An inspection of each acme screw for wear and cracking;
    (ii) Lubricating all drive threads and gears; and
    (iii) A test to ensure proper operation of the extend and 
retract travel limit switches.
    (3) If the last overhaul of an LCTA was approved for return to 
service by a person that meets the requirements of 14 CFR part 43, 
overhaul the LCTA (to include the overhaul requirements specified in 
paragraphs (g)(2)(i) through (iii) of this AD) within 500 hours TIS 
or 3,000 lift cycles since last overhaul, whichever occurs first; or 
within 90 days after the effective date of this AD, whichever occurs 
later. Thereafter, overhaul each LCTA at intervals not to exceed 
3,000 hours TIS or 18,000 lift cycles, whichever occurs first.
    (4) As of the effective date of this AD, do not install any LCTA 
on any helicopter

[[Page 71823]]

unless it has been approved for return to service by a person that 
meets the requirements of 14 CFR part 43 after an overhaul that 
includes the overhaul requirements specified in paragraphs (g)(2)(i) 
through (iii) of this AD, and that LCTA has not been in service for 
more than 3,000 hours TIS or 18,000 lift cycles since that overhaul.
    (5) Within 10 days after completing each LCTA overhaul required 
by this AD, provide the following information by email to 
[email protected] and [email protected]; or by mail to 
Vaughn Schmitt and Ian Hansen, Aircraft Evaluation Group, Safety 
Standards Division, FAA, 10101 Hillwood Parkway, Fort Worth, TX 
76177:
    (i) Helicopter Owner/Operator name, email, address, and 
telephone number,
    (ii) LCTA model, part number and serial number,
    (iii) Months TIS since last LCTA overhaul,
    (iv) Operating hours and lift cycles since last LCTA overhaul,
    (v) Date and location of last LCTA overhaul,
    (vi) LCTA repairs since last LCTA overhaul,
    (vii) LCTA condition when removed,
    (viii) LCTA reports of failures or degraded functions,
    (ix) LCTA part replacements,
    (x) Point of contact information for additional information,
    (xi) Any additional notes or comments, and
    (xii) Pictures, if available.

(h) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle ACO Branch, FAA, has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request 
to your principal inspector or local Flight Standards District 
Office, as appropriate. If sending information directly to the 
manager of the certification office, send it to the attention of the 
person identified in paragraph (i) of this AD. Information may be 
emailed to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(i) Related Information

    For more information about this AD, contact David Herron, 
Aerospace Engineer, Systems & Equipment Section, Seattle ACO Branch, 
FAA, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 
(206) 231-3554; email [email protected].

(j) Material Incorporated by Reference

    None.

    Issued on December 6, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-27539 Filed 12-16-21; 11:15 am]
BILLING CODE 4910-13-P