Document ID: FAA-2015-4007-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Various Model 234 and Model CH-47D Helicopters
Posted Date: 2017-03-14T04:00Z

[Federal Register Volume 82, Number 48 (Tuesday, March 14, 2017)]
[Proposed Rules]
[Pages 13567-13569]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-04735]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-4007; Directorate Identifier 2015-SW-064-AD]
RIN 2120-AA64

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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
various Model 234 and Model CH-47D helicopters. This proposed AD would 
require inspections of the pitch housing and revising the pitch housing 
retirement life. This proposed AD is prompted by reports of cracking in 
the pitch housing lugs. The proposed actions are intended to detect and 
prevent an unsafe condition on these products.

DATES: We must receive comments on this proposed AD by May 15, 2017.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Docket: Go to http://www.regulations.gov. Follow the online instructions for sending your 
comments electronically.
     Fax: 202-493-2251.
     Mail: Send comments to the U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590-0001.
     Hand Delivery: Deliver to the ``Mail'' address between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2015-
4007; or in person at the Docket Operations Office between 9 a.m. and 5 
p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this proposed AD, the economic evaluation, the Special 
Airworthiness Information Bulletin (SAIB), any comments received, and 
other information. The street address for the Docket Operations Office 
(telephone 800-647-5527) is in the ADDRESSES section. Comments will be 
available in the AD docket shortly after receipt.
    For service information identified in this proposed AD, contact 
Boeing Helicopters, The Boeing Company, 1 S. Stewart Avenue, Ridley 
Park, PA 19078, telephone 610-591-2121, and Columbia Helicopters, Inc. 
(Columbia), 14452 Arndt Road NE., Aurora OR 97002, telephone (503) 678-
1222, fax (503) 678-5841, or at http://www.colheli.com. You may review 
the referenced service information at the FAA, Office of the Regional 
Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort 
Worth, TX 76177.

FOR FURTHER INFORMATION CONTACT: Kathleen Arrigotti, Aerospace 
Engineer, Seattle Aircraft Certification Office, Transport Airplane 
Directorate, FAA, 1601 Lind Avenue SW., Renton, Washington 98057; 
telephone (425) 917-6426; email Kathleen.Arrigotti@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to participate in this rulemaking by submitting 
written comments, data, or views. We also invite comments relating to 
the economic, environmental, energy, or federalism impacts that might 
result from adopting the proposals in this document. The most helpful 
comments reference a specific portion of the proposal, explain the 
reason for any recommended change, and include supporting data. To 
ensure the docket does not contain duplicate comments, commenters 
should send only one copy of written comments, or if comments are filed 
electronically, commenters should submit only one time.
    We will file in the docket all comments that we receive, as well as 
a report summarizing each substantive public contact with FAA personnel 
concerning this proposed rulemaking. Before acting on this proposal, we 
will consider all comments we receive on or before the closing date for 
comments. We will consider comments filed after the comment period has 
closed if it is possible to do so without incurring

[[Page 13568]]

expense or delay. We may change this proposal in light of the comments 
we receive.

Discussion

    We propose to adopt an AD for helicopters with a pitch housing part 
number (P/N) 145R2075-11, 145R2075-12, 145R2075-13, 145R2075-14, 
145R2075-15, 145R2075-16, 234R2075-1, or 234R2075-2 installed. These 
pitch housings are installed on Model 234 and Model CH-47D helicopters. 
The type certificate (TC) holder for Model 234 helicopters is Columbia 
(type certificate previously held by Boeing Defense & Space Group), and 
the type certificate holders for Model CH-47D helicopters currently 
include Columbia, Billings Flying Service, Inc., and Tandem Rotor, LLC. 
We are not limiting this proposed AD to the type certificate holders 
listed above because we expect additional type certificate holders of 
helicopters that are subject to this same unsafe condition.
    This proposed AD is prompted by reports of cracking in the pitch 
housing lugs. In November 2007, Boeing reported the failure of an aft 
rotor pitch housing lower lug on a Model CH-47 helicopter operated by 
the Japanese Ground Self Defense Force. On March 26, 2009, a Model 234 
helicopter also experienced a failure because of a crack on an aft 
rotor pitch housing lower lug. In both cases, the cracking was located 
on the lead side of the lower vertical pin lug and had initiated in the 
bore. The crack grew outward by fatigue, initiated by fretting damage.
    Those incidents prompted the FAA to issue SAIB SW-11-03, dated 
October 22, 2010. The SAIB recommends that all owners and operators of 
Columbia Model 234 helicopters perform repetitive ultrasonic 
inspections of the lugs. At that time, there were no civil Model CH-47D 
helicopters in service.
    On March 20, 2015, we received a report of lateral vibration on a 
Model 234 helicopter that prompted an immediate landing. A subsequent 
investigation found that a crack in an aft pitch housing upper lug 
resulted in the lateral vibrations. The pitch housing had accumulated 
11,733 hours time-in-service (TIS). The crack was determined to be 
caused by fatigue and attributed to underestimated load conditions in 
the original life limit calculations. This cracking differed from the 
cracking described in the SAIB because the cracking initiated at the 
outer surface of the pitch housing lug and grew inward toward the bore.
    To correct this unsafe condition, we propose to require repetitive 
eddy current and ultrasonic inspections of the pitch housing. Based on 
the proximity of the most recent inward-growing crack to the outward 
cracks described in the SAIB, we propose to require ultrasonic 
inspections of the pitch housing, as recommended in the SAIB. Boeing, 
the original manufacturer of both model helicopters, developed service 
information for the SAIB ultrasonic inspections, which we would require 
in this proposed AD. Due to the rapid growth rate, an effective eddy 
current inspection must detect an inward-growing crack of no more than 
0.10 inch. This proposed AD would require, for Columbia helicopters, 
the eddy current inspection method specified in Columbia's service 
information. Because the other TC holders have not developed service 
instructions, we propose to require the eddy current inspection 
procedures for all other helicopters be submitted to the Seattle or 
Denver Aircraft Certification Offices for approval.
    We are also proposing to require removing the pitch housing from 
service when it accumulates a total of 8,200 hours TIS. Forward pitch 
housings on Model CH-47D helicopters have no life limit and the aft 
pitch housing already has a life limit of 8,200 hours TIS. For Model 
234 helicopters, the forward pitch housing has a life limit of 12,547 
hours TIS and the aft pitch housing has a life limit of 19,077 hours 
TIS. This proposed AD would establish or reduce these life limits to 
8,200 hours TIS for both forward and aft pitch housings, regardless of 
the model helicopter.
    The actions specified by this proposed AD are intended to detect 
and prevent a crack in a pitch housing lug. This condition could result 
in loss of a rotor blade and consequent loss of helicopter control.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of these same type 
designs.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Service Bulletin 145R2075-62-0001, Revision 1, 
dated September 27, 2011, which specifies updated life limits for the 
forward and aft pitch housings and revised overhaul and ultrasonic 
inspection procedures for various military Model CH-47 and 234 
helicopters.
    We also reviewed Columbia Helicopters, Inc., Alert Service Bulletin 
No. 234-62-A0012, Revision 2, dated March 1, 2016, for Model 234 
helicopters; and Alert Service Bulletin No. 47D-62-A0002, Revision 0, 
dated March 1, 2016, for Model CH-47D helicopters. This service 
information specifies procedures for performing repetitive eddy current 
inspections, visual inspections, and ultrasonic inspections and for 
reducing the life limit of the pitch housing assemblies.
    This service information is reasonably available because the 
interested parties have access to it through their normal course of 
business or by the means identified in the ADDRESSES section.

Proposed AD Requirements

    This proposed AD would require:
    Before further flight, removing from service any pitch housing P/N 
145R2075-11, 145R2075-12, 145R2075-13, 145R2075-14, 145R2075-15, 
145R2075-16, 234R2075-1, and 234R2075-2 that has accumulated 8,200 
hours total time-in-service (TIS).
    Before the pitch housing accumulates 200 hours TIS after the 
effective date of this proposed AD and thereafter at intervals not to 
exceed 200 hours TIS, ultrasonic inspecting the pitch housing for a 
crack and replacing any cracked pitch housing. Within 400 hours TIS or 
before the pitch housing accumulates 4,000 hours total TIS, whichever 
occurs later, and thereafter at intervals not to exceed 500 hours TIS, 
eddy current inspecting the pitch housing for a crack and replacing any 
cracked pitch housing.
    For Columbia helicopters, this eddy current inspection would be 
performed in accordance with the Columbia service information. For all 
other helicopters, this proposed AD would require that the method for 
the eddy current inspection be approved by the Manager, Seattle 
Aircraft Certification Office (ACO) or Manager, Denver ACO.

Differences Between This Proposed AD and the Service Information

    The service information provides different life limits for the 
forward and aft pitch housings, while this proposed AD would require a 
life limit of 8,200 hours TIS for all pitch housings. The service 
information requires either an ultrasonic inspection or a dye penetrant 
inspection as part of the overhaul procedures. The service information 
specifies different compliance times for the inspections than what 
would be required by this proposed AD.

Costs of Compliance

    We estimate that this proposed AD would affect 15 helicopters of 
U.S. Registry and that labor costs would average $85 per work-hour. 
Based on

[[Page 13569]]

these estimates, we expect the following costs:
     An eddy current inspection would require 4 work-hours for 
a total cost of $340 per helicopter and $5,100 for the U.S. fleet, per 
inspection cycle.
     An ultrasonic inspection would require 4 work-hours for a 
total cost of $340 per helicopter and $5,100 for the U.S. fleet, per 
inspection cycle.
     Replacing a pitch housing would require 8 work-hours and 
parts would cost $13,000, for a total cost of $13,680 per helicopter.

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.
    We are 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

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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, I certify that this proposed AD:
    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);
    3. Will not affect intrastate aviation in Alaska to the extent that 
it justifies making a regulatory distinction; and
    4. 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.
    We prepared an economic evaluation of the estimated costs to comply 
with this proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

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

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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 (AD):

Various Model 234 and Model CH-47D Helicopters: Docket No. FAA-2015-
4007; Directorate Identifier 2015-SW-64-AD.

(a) Applicability

    This AD applies to Model 234 and Model CH-47D helicopters, 
regardless of type certificate holder, with a pitch housing assembly 
(pitch housing) part number (P/N) 145R2075-11, 145R2075-12, 
145R2075-13, 145R2075-14, 145R2075-15, 145R2075-16, 234R2075-1, or 
234R2075-2 installed, certificated in any category.

(b) Unsafe Condition

    This AD defines the unsafe condition as a crack in a pitch 
housing lug. This condition could result in loss of a rotor blade 
and consequent loss of helicopter control.

(c) Comments Due Date

    We must receive comments by May 15, 2017.

(d) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless it has already been 
accomplished prior to that time.

(e) Required Actions

    (1) Before further flight, remove from service any pitch housing 
P/N 145R2075-11, 145R2075-12, 145R2075-13, 145R2075-14, 145R2075-15, 
145R2075-16, 234R2075-1, and 234R2075-2 that has accumulated 8,200 
hours total time-in-service (TIS).
    (2) Before the pitch housing accumulates 200 hours TIS after the 
effective date of this AD and thereafter at intervals not to exceed 
200 hours TIS, ultrasonic inspect the pitch housing for a crack in 
accordance with Attachment 1, paragraphs F and H through K, of 
Boeing Service Bulletin 145R2075-62-0001, Revision 1, dated 
September 27, 2011. If there is a crack, replace the pitch housing 
before further flight.
    (3) Within 400 hours TIS or before the pitch housing has 
accumulated 4,000 hours total TIS, whichever occurs later, and 
thereafter at intervals not to exceed 500 hours TIS:
    (i) For Columbia Helicopters, Inc., Model 234 and CH-47D 
helicopters, eddy current inspect the pitch housing for a crack by 
following paragraphs 3.C.(1) and 3.C.(2) of Columbia Helicopters, 
Inc., Alert Service Bulletin No. 234-62-A0012, Revision 2, dated 
March 1, 2016, or Alert Service Bulletin No. 47D-62-A0002, Revision 
0, dated March 1, 2016, as applicable to your model helicopter. If 
there is a crack, replace the pitch housing before further flight.
    (ii) For all other helicopters, eddy current inspect the pitch 
housing for a crack. If there is a crack, replace the pitch housing 
before further flight. The eddy current inspection must be 
accomplished using a method approved by the Manager, Seattle 
Aircraft Certification Office (ACO) or Manager, Denver ACO. For a 
repair method to be approved as required by this AD, the Manager's 
approval letter must specifically refer to this AD.

(f) Alternative Methods of Compliance (AMOCs)

    (1) For operators of helicopters with type certificates issued 
by the Denver Aircraft Certification Office, the manager of the 
Denver Aircraft Certification Office, FAA, may approve AMOCs for 
this AD. Send your proposal to: Greg Johnson, Senior Aerospace 
Engineer, Denver Aircraft Certification Office, 26805 East 68th 
Avenue, Denver, CO 80249; phone: 303-342-1083; fax: 303-342-1088; 
email: Gregory.Johnson@faa.gov.
    (2) All other AMOC requests should be sent to the Manager, 
Seattle Aircraft Certification Office, FAA. Send your proposal to: 
Kathleen Arrigotti, Aerospace Engineer, Seattle Aircraft 
Certification Office, Transport Airplane Directorate, FAA, 1601 Lind 
Avenue SW., Renton, Washington 98057; telephone (425) 917-6426; 
email 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (3) For operations conducted under a 14 CFR part 119 operating 
certificate or under 14 CFR part 91, subpart K, we suggest that you 
notify your principal inspector, or lacking a principal inspector, 
the manager of the local flight standards district office or 
certificate holding district office before operating any aircraft 
complying with this AD through an AMOC.

(g) Additional Information

    Special Airworthiness Information Bulletin SW-11-03, dated 
October 22, 2010 (SAIB), which is not incorporated by reference, 
contains additional information about the subject of this AD. You 
may view the SAIB on the internet at http://www.regulations.gov in 
the AD Docket.

(h) Subject

    Joint Aircraft Service Component (JASC) Code: 6220, Main Rotor 
Head.

    Issued in Fort Worth, Texas, on March 1, 2017.
Scott A. Horn,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2017-04735 Filed 3-13-17; 8:45 am]
 BILLING CODE 4910-13-P