This section of the FEDERAL REGISTER

contains notices to the public of the proposed

issuance of rules and regulations. The

purpose of these notices is to give interested

persons an opportunity to participate in the

rule making prior to the adoption of the final

rules.

Proposed Rules Federal Register

34163 

Vol. 86, No. 122 

Tuesday, June 29, 2021 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2021–0514; Project 

Identifier MCAI–2020–01570–T] 

RIN 2120–AA64 

Airworthiness Directives; De Havilland 

Aircraft of Canada Limited (Type 

Certificate Previously Held by 

Bombardier, Inc.) Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for 

certain De Havilland Aircraft of Canada 

Limited Model DHC–8–400, –401, and 

–402 airplanes. This proposed AD was 

prompted by a report that the epoxy 

primer on the internal bore of the 

nacelle and landing gear attachment 

pins was not applied, and corrosion on 

the internal bore of the wing rear spar 

attachment pins was found. This 

proposed AD would require doing a 

detailed visual inspection of the nacelle 

to wing rear spar attachment pins, and 

the nacelle and landing gear attachment 

pins, for any corrosion, and doing all 

applicable corrective actions. The FAA 

is proposing this AD to address the 

unsafe condition on these products. 

DATES: The FAA must receive comments 

on this proposed AD by August 13, 

2021. 

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. 

For service information identified in 

this NPRM, contact De Havilland 

Aircraft of Canada Limited, Q-Series 

Technical Help Desk, 123 Garratt 

Boulevard, Toronto, Ontario M3K 1Y5, 

Canada; telephone 416–375–4000; fax 

416–375–4539; email thd@

dehavilland.com; internet https://

dehavilland.com. You may view this 

service information at the FAA, 

Airworthiness Products Section, 

Operational Safety Branch, 2200 South 

216th St., Des Moines, WA. For 

information on the availability of this 

material at the FAA, call 206–231–3195. 

Examining the AD Docket 

You may examine the AD docket at 

https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2021–0514; 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 

NPRM, any comments received, and 

other information. The street address for 

Docket Operations is listed above. 

FOR FURTHER INFORMATION CONTACT: 

Deep Gaurav, Aerospace Engineer, 

Airframe and Propulsion Section, FAA, 

New York ACO Branch, 1600 Stewart 

Avenue, Suite 410, Westbury, NY 

11590; telephone 516–228–7300; fax 

516–794–5531; email 9-avs-nyaco-cos@

faa.gov. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

The FAA invites you to send any 

written relevant data, views, or 

arguments about this proposal. Send 

your comments to an address listed 

under ADDRESSES. Include ‘‘Docket No. 

FAA–2021–0514; Project Identifier 

MCAI–2020–01570–T’’ at the beginning 

of your comments. The most helpful 

comments reference a specific portion of 

the proposal, 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 the proposal 

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 NPRM. 

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 NPRM 

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 NPRM, 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 

NPRM. Submissions containing CBI 

should be sent to Deep Gaurav, 

Aerospace Engineer, Airframe and 

Propulsion Section, FAA, New York 

ACO Branch, 1600 Stewart Avenue, 

Suite 410, Westbury, NY 11590; 

telephone 516–228–7300; fax 516–794– 

5531; email 9-avs-nyaco-cos@faa.gov. 

Any commentary that the FAA receives 

which is not specifically designated as 

CBI will be placed in the public docket 

for this rulemaking. 

Background 

Transport Canada Civil Aviation 

(TCCA), which is the aviation authority 

for Canada, has issued TCCA AD CF– 

2020–51R1, dated February 24, 2021 

(also referred to after this as the 

Mandatory Continuing Airworthiness 

Information, or the MCAI), to correct an 

unsafe condition for certain De 

Havilland Aircraft of Canada Limited 

Model DHC–8–400, –401, and –402 

airplanes. You may examine the MCAI 

in the AD docket at https://

www.regulations.gov by searching for 

and locating Docket No. FAA–2021– 

0514. 

This proposed AD was prompted by 

a report that the epoxy primer on the 

internal bore of the nacelle and landing 

gear attachment pins was not applied, 

and corrosion on the internal bore of the 

wing rear spar attachment pins was 

found. The FAA is proposing this AD to 


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34164 Federal Register / Vol. 86, No. 122 / Tuesday, June 29, 2021 / Proposed Rules 

address premature corrosion and 

subsequent failure of the nacelle to 

landing gear and nacelle to rear wing 

spar attachment pins, which if 

undetected, could lead to a single or 

dual collapse of the main landing gear. 

See the MCAI for additional background 

information. 

Related Service Information Under 1 

CFR Part 51 

De Havilland Aircraft of Canada 

Limited has issued-Service Bulletin 84– 

54–28, Revision B, dated January 24, 

2020; and Service Bulletin 84–54–31, 

Revision B, dated February 21, 2020. 

This service information describes 

procedures for doing a detailed visual 

inspection of the nacelle to wing rear 

spar attachment pins, and the nacelle 

and landing gear attachment pins, for 

any corrosion; and doing all applicable 

corrective actions. Corrective actions 

include applying epoxy primer to the 

bore surface of the pins, a fluorescent 

magnetic particle inspection for any 

cracking, corrosion removal, reworking 

and part marking certain pins, and 

replacing any cracked or corroded pins 

with serviceable pins. These documents 

are distinct since they apply to different 

airplane configurations. 

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. 

FAA’s Determination 

This product has been approved by 

the aviation authority of another 

country, and is approved for operation 

in the United States. Pursuant to the 

FAA’s bilateral agreement with the State 

of Design Authority, the FAA has been 

notified of the unsafe condition 

described in the MCAI and service 

information referenced above. The FAA 

is proposing this AD because the FAA 

evaluated all the relevant information 

and determined the unsafe condition 

described previously is likely to exist or 

develop on other products of the same 

type design. 

Proposed AD Requirements in This 

NPRM 

This proposed AD would require 

accomplishing the actions specified in 

the service information already 

described. 

Differences Between This Proposed AD 

and the MCAI or Service Information 

Where Part III of TCCA CF–2020– 

51R1, dated February 24, 2021, specifies 

a detailed visual inspection and 

rectification of the nacelle and landing 

gear attachment pins, this AD requires 

a re-part mark of the yoke attachment 

pin as specified in Part B of the 

Accomplishment Instructions of De 

Havilland Service Bulletin 84–54–31, 

Revision B, dated February 21, 2020. 

Costs of Compliance 

The FAA estimates that this AD, if 

adopted as proposed, would affect 41 

airplanes of U.S. registry. The FAA 

estimates the following costs to comply 

with this proposed AD: 

ESTIMATED COSTS FOR REQUIRED ACTIONS

Labor cost Parts cost Cost per product Cost on U.S. operators 

Up to 9 work-hours × $85 per hour = Up to $765 ..... $0 Up to $765 ..................................... Up to $31,365. 

The FAA has received no definitive 

data on which to base the cost estimates 

for the on-condition actions specified in 

this proposed AD. 

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 

The FAA 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 above, I 

certify this proposed regulation: 

(1) Is not a ‘‘significant regulatory 

action’’ under Executive Order 12866, 

(2) Would not affect intrastate 

aviation in Alaska, and 

(3) Would not have a significant 

economic impact, positive or negative, 

on a substantial number of small entities 

under the criteria of the Regulatory 

Flexibility Act. 

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 

■ 1. The authority citation for part 39 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701. 

§ 39.13 [Amended] 

■ 2. The FAA amends § 39.13 by adding 

the following new airworthiness 

directive: 

De Havilland Aircraft of Canada Limited 

(Type Certificate Previously Held by 

Bombardier, Inc.): Docket No. FAA– 

2021–0514; Project Identifier MCAI– 

2020–01570–T. 

(a) Comments Due Date 

The FAA must receive comments on this 

airworthiness directive (AD) by August 13, 

2021. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to De Havilland Aircraft 

of Canada Limited (type certificate 

previously held by Bombardier, Inc.) Model 

DHC–8–400, –401, and –402 airplanes, 

certificated in any category, serial numbers 

4001, 4003 through 4550 inclusive, 4583 

through 4585 inclusive, 4587, 4588, and 

4590. 

(d) Subject 

Air Transport Association (ATA) of 

America Code 54, Nacelles/pylons. 

(e) Unsafe Condition 

This AD was prompted by a report that the 

epoxy primer on the internal bore of the 


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Federal Register / Vol. 86, No. 122 / Tuesday, June 29, 2021 / Proposed Rules 34165 

nacelle and landing gear attachment pins was 

not applied, and corrosion on the internal 

bore of the wing rear spar attachment pins 

was found. The FAA is issuing this AD to 

address premature corrosion and subsequent 

failure of the nacelle to landing gear and 

nacelle to rear wing spar attachment pins, 

which if undetected, could lead to a single 

or dual collapse of the main landing gear. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Inspection and Corrective Actions 

(1) At the applicable compliance times 

specified in paragraphs (g)(1)(i) through (iii) 

of this AD: Do a detailed visual inspection of 

the nacelle to wing rear spar attachment pins, 

and the nacelle and landing gear attachment 

pins, for any cracking or corrosion, and do 

all applicable corrective actions, in 

accordance with Part A or Part B, as 

applicable, of Section 3., ‘‘Accomplishment 

Instructions,’’ of the applicable service 

information specified in figure 1 to paragraph 

(g) of this AD. Do all applicable corrective 

actions before further flight. 

(i) For nacelle to wing rear spar attachment 

pins, or nacelle and landing gear attachment 

pins, as applicable, that have accumulated 

less than 26,000 flight cycles as of the 

effective date of this AD, and have been in 

service less than 12 years from their entryinto-service as of the effective date of this 

AD: Prior to the pins reaching 14 years from 

their entry-into-service, or prior to the 

airplane reaching 30,000 total flight cycles, 

whichever occurs first. 

(ii) For nacelle to wing rear spar 

attachment pins, or nacelle and landing gear 

attachment pins, as applicable, that have 

accumulated 26,000 flight cycles or more as 

of the effective date of this AD, or have been 

in service 12 years or more from their entryinto-service as of the effective date of this 

AD: Within 4 years or 8,000 flight hours after 

the effective date of this AD, whichever 

occurs first. 

(iii) For airplanes on which the actions 

specified in Bombardier Service Bulletin 84– 

54–27, dated August 11, 2017; or Bombardier 

Service Bulletin 84–54–28, dated August 11, 

2017; as applicable, have been accomplished: 

Within 14 years or 30,000 flight cycles after 

the date of incorporation of Bombardier 

Service Bulletin 84–54–27, dated August 11, 

2017; or Bombardier Service Bulletin 84–54– 

28, dated August 11, 2017; as applicable, 

whichever occurs first. 

(2) For serial numbers 4583, 4584, 4585, 

4587, 4588 and 4590: At the applicable 

compliance times specified in paragraphs 

(g)(1)(i) through (iii) of this AD, re-part mark 

the yoke attachment pin, in accordance with 

Part B of the Accomplishment Instructions of 

De Havilland Service Bulletin 84–54–31, 

Revision B, dated February 21, 2020. 

(h) Credit for Previous Actions 

This paragraph provides credit for actions 

required by paragraph (g) of this AD, if those 

actions were performed before the effective 

date of this AD using the applicable service 

information specified in paragraphs (h)(1) 

through (3) of this AD. 

(1) Bombardier Service Bulletin 84–54–28, 

Revision A, dated April 10, 2019. 

(2) Bombardier Service Bulletin 84–54–31, 

dated May 1, 2019. 

(3) Bombardier Service Bulletin 84–54–31, 

Revision A, dated October 15, 2019. 

(i) No Reporting Requirement 

Although De Havilland Service Bulletin 

84–54–28, Revision B, dated January 24, 

2020; and De Havilland Service Bulletin 84– 

54–31, Revision B, dated February 21, 2020; 

specify to submit certain information to the 

manufacturer, this AD does not include that 

requirement. 

(j) Other FAA AD Provisions 

The following provisions also apply to this 

AD: 

(1) Alternative Methods of Compliance 

(AMOCs): The Manager, New York 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 

responsible Flight Standards Office, as 

appropriate. If sending information directly 

to the manager of the certification office, 

send it to ATTN: Program Manager, 

Continuing Operational Safety, FAA, New 

York ACO Branch, 1600 Stewart Avenue, 

Suite 410, Westbury, NY 11590; telephone 

516–228–7300; fax 516–794–5531. Before 

using any approved AMOC, notify your 

appropriate principal inspector, or lacking a 

principal inspector, the manager of the 

responsible Flight Standards Office. 

(2) Contacting the Manufacturer: For any 

requirement in this AD to obtain instructions 

from a manufacturer, the instructions must 

be accomplished using a method approved 

by the Manager, New York ACO Branch, 

FAA; or Transport Canada Civil Aviation 

(TCCA); or De Havilland Aircraft of Canada 

Limited’s TCCA Design Approval 

Organization (DAO). If approved by the DAO, 

the approval must include the DAOauthorized signature. 

(k) Related Information 

(1) Refer to Mandatory Continuing 

Airworthiness Information (MCAI) TCCA AD 

CF–2020–51R1, dated February 24, 2021, for 

related information. This MCAI may be 

found in the AD docket on the internet at 

https://www.regulations.gov by searching for 

and locating Docket No. FAA–2021–0514. 

(2) For more information about this AD, 

contact Deep Gaurav, Aerospace Engineer, 

Airframe and Propulsion Section, FAA, New 

York ACO Branch, 1600 Stewart Avenue, 

Suite 410, Westbury, NY 11590; telephone 

516–228–7300; fax 516–794–5531; email 9- 

avs-nyaco-cos@faa.gov. 

(3) For service information identified in 

this AD, contact De Havilland Aircraft of 

Canada Limited, Q-Series Technical Help 

Desk, 123 Garratt Boulevard, Toronto, 

Ontario M3K 1Y5, Canada; telephone 416– 

375–4000; fax 416–375–4539; email thd@

dehavilland.com; internet https://

dehavilland.com. You may view this service 

information at the FAA, Airworthiness 

Products Section, Operational Safety Branch, 

2200 South 216th St., Des Moines, WA. For 

information on the availability of this 

material at the FAA, call 206–231–3195. 

Issued on June 23, 2021. 

Lance T. Gant, 

Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2021–13726 Filed 6–28–21; 8:45 am] 

BILLING CODE 4910–13–P 


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Figure 1 to paragraph (g) - Service Information 

Serial Numbers- Service Information4001, 4003 through 4550 De Havilland Service Bulletin 84-54-28, Revision B, 

inclusive dated January 24, 2020 

4001, 4003 through 4533 De Havilland Service Bulletin 84-54-31, Revision B, 

inclusive, 4583 through dated February 21, 2020 

4585 inclusive, 4587, 

4588 and 4590