Federal Register / Vol. 86, No. 138 / Thursday, July 22, 2021 / Proposed Rules 38613 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2021–0573; Project 

Identifier 2018–CE–046–AD] 

RIN 2120–AA64 

Airworthiness Directives; Pilatus 

Aircraft Ltd. 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 

Pilatus Aircraft Ltd. (Pilatus) Models 

PC–12/45, PC–12/47, and PC–12/47E 

airplanes with Supplemental Type 

Certificate (STC) SA00634DE installed. 

This proposed AD was prompted by a 

report of strake attachment brackets and 

the fuselage frame failing at the upper 

most bracket attachment location. This 

proposed AD would require inspecting 

the strake, attachment brackets, 

surrounding structure, and bolts and 

replacing components and repairing 

damage if necessary. 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 September 7, 

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 Pilatus Business 

Aircraft Ltd., Customer Support 

Department, 12300 Pilatus Way, 

Broomfield, CO 80021; phone: (866) 

721–2435; fax: (303) 465–9099; email: 

productsupport@pilbal.com. You may 

view this service information at the 

FAA, Airworthiness Products Section, 

Operational Safety Branch, 901 Locust, 

Kansas City, MO 64106. For information 

on the availability of this material at the 

FAA, call (816) 329–4148. 

Examining the AD Docket 

You may examine the AD docket at 

https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2021–0573; 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: 

Richard R. Thomas, Aviation Safety 

Engineer, Denver ACO Branch, FAA, 

26805 E 68th Avenue, Denver, CO 

80249; phone: (303) 342–1080; fax: (303) 

342–1088; email: 9-Denver-AircraftCert@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–2021–0573; Project Identifier 

2018–CE–046–AD’’ 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 this 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 Richard R. Thomas, 

Aviation Safety Engineer, Denver ACO 

Branch, FAA, 26805 E 68th Avenue, 

Denver, CO 80249. Any commentary 

that the FAA receives which is not 

specifically designated as CBI will be 

placed in the public docket for this 

rulemaking. 

Background 

The FAA received a report that an 

operator found that one of the fuselage 

strakes was ‘‘loose having excess play’’ 

on two different Pilatus Model PC–12/ 

47E airplanes. Further inspection found 

the fuselage main frame at frame station 

40 and the strake attachment brackets 

had cracks extending from the 

attachment bolt hole at the upper most 

attachment location. Both airplanes had 

a SPECTRE Lift Platform System, STC 

SA00634DE, installed. The deployment 

of the lift platform causes buffeting of 

the strakes. This condition, if not 

addressed, could result in airplane 

flutter and reduced lateral stability, 

which may lead to loss of control of the 

airplane. 

FAA’s Determination 

The FAA is issuing this NPRM after 

determining that the unsafe condition 

described previously is likely to exist or 

develop on other products of the same 

type design. 

Related Service Information Under 1 

CFR Part 51 

The FAA reviewed Pilatus Service 

Bulletin PC–12 Series, Report Number 

12–1700–64–0000, Revision B, dated 

August 10, 2018 (Pilatus Report 12– 

1700–64–0000B), which contains 

procedures for inspection of all fuselage 

strake attachment bolts and the 

surrounding structure. 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 ADDRESSES. 

Proposed AD Requirements in This 

NPRM 

This proposed AD would require 

inspecting the strake, attachment 

brackets, and bolts for movement and 

damage, both internal and external, and 

replacing or repairing any damaged 

parts. 

Differences Between This Proposed AD 

and the Service Information 

Pilatus Report 12–1700–64–0000B 

specifies a one-time inspection within 

10 flight hours of issuance of the SB and 

recommends repeat inspections without 

specifying an inspection interval. This 


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38614 Federal Register / Vol. 86, No. 138 / Thursday, July 22, 2021 / Proposed Rules 

proposed AD would require repeating 

the inspection every 150 flight hours. 

Pilatus Report 12–1700–64–0000B 

specifies contacting Pilatus for further 

instructions. This proposed AD would 

require using an FAA-approved repair 

method. Pilatus Report 12–1700–64– 

0000B applies to Pilatus PC–12 aircraft 

serial numbers 190 to 1575. This 

proposed AD would apply to all Pilatus 

Aircraft Ltd. Models PC–12/45, PC–12/ 

47, and PC–12/47E airplanes, regardless 

of serial number, if STC SA00634DE is 

installed. 

Interim Action 

The FAA considers this AD an 

interim action. Pilatus is working on a 

modification with the intent of 

minimizing, if not eliminating, the 

buffeting of the strakes. Once this action 

is developed, approved, and available, 

the FAA may consider additional 

rulemaking. 

Costs of Compliance 

The FAA estimates that this AD, if 

adopted as proposed, would affect 30 

airplanes of U.S. registry. 

The FAA estimates the following 

costs to comply with this proposed AD: 

ESTIMATED COSTS

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

operators 

Inspection of the strake assemblies.1 work-hour × $85 per hour 

= $85 per inspection cycle.

Not applicable ..... $85 per inspection cycle ....... $2,550 per inspection cycle. 

The extent of damage found during 

the proposed inspections may vary 

considerably from airplane to airplane. 

The FAA has no way of knowing how 

many airplanes may have damage or the 

extent of damage each airplane may 

have. 

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: 

Pilatus Aircraft Ltd.: Docket No. FAA– 

2021–0573; Project Identifier 2018–CE–046– 

AD. 

(a) Comments Due Date 

The FAA must receive comments on this 

airworthiness directive (AD) by September 7, 

2021. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to Pilatus Aircraft Ltd. 

(Pilatus) Models PC–12/45, PC–12/47, and 

PC–12/47E airplanes, all serial numbers, 

certificated in any category, with a Spectre 

Lift Platform System installed in accordance 

with Supplemental Type Certificate No. 

SA00634DE. 

(d) Subject 

Joint Aircraft System Component (JASC) 

Code 5350, Aerodynamic Faring. 

(e) Unsafe Condition 

This AD was prompted by a report of the 

strake attachment brackets and surrounding 

structure failing at the upper most bracket 

bolt hole. The FAA is issuing this AD to 

detect and address any looseness or damage 

to the strake, attachment brackets or 

surrounding structure, and missing fasteners 

or loose bolts, which could result in airplane 

flutter and reduced lateral stability, which 

may lead to loss of control of the airplane. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Inspection and Corrective Actions 

Within 10 hours time-in-service (TIS) after 

the effective date of this AD and thereafter at 

intervals not to exceed 150 hours TIS, inspect 

the outside and inside fuselage strakes for 

movement, the strakes and their attachment 

brackets for loose and missing bolts and 

screws, and the strake attachment brackets 

and surrounding structure for discoloration, 

deformation, cracks, and other structural 

damage by following the Accomplishment 

Instructions—Aircraft, steps A through B.(3) 

and C.(1) through C.(5), in Pilatus Service 

Bulletin PC–12 Series, Report Number 12– 

1700–64–0000, Revision B, dated August 10, 

2018. 

(1) You must accomplish the inside 

fuselage inspection regardless of the results 

of the outside fuselage inspection. 

(2) If any movement of the strakes, a loose 

or missing bolt or screw, discoloration, 

deformation, a crack, or other structural 

damage is found during any of the 

inspections, before further flight, repair using 

FAA-approved procedures. 

(h) Special Flight Permit 

A special flight permit may be issued to 

allow flying the airplane to a maintenance 

facility where repair of the strake assembly 

will be performed with the following 

operating limitations: 


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Federal Register / Vol. 86, No. 138 / Thursday, July 22, 2021 / Proposed Rules 38615 

(1) Flight must be conducted under visual 

flight rules, daytime only; and 

(2) The Spectre Lift Platform System, STC 

SA00634DE, must be retracted (not deployed) 

during the flight. 

(i) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager, Denver 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 Related Information. 

(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. 

(j) Related Information 

(1) For more information about this AD, 

contact Richard R. Thomas, Aviation Safety 

Engineer, Denver ACO Branch, FAA, 26805 

E 68th Avenue, Denver, CO 80249; phone: 

(303) 342–1080; fax: (303) 342–1088; email: 

9-Denver-Aircraft-Cert@faa.gov. 

(2) For service information identified in 

this AD, contact Pilatus Business Aircraft 

Ltd., Customer Support Department, 12300 

Pilatus Way, Broomfield, CO 80021; phone: 

(866) 721–2435; fax: (303) 465–9099; email: 

productsupport@pilbal.com. You may view 

this referenced service information at the 

FAA, Airworthiness Products Section, 

Operational Safety Branch, 901 Locust, 

Kansas City, MO 64106. For information on 

the availability of this material at the FAA, 

call (816) 329–4148. 

Issued on July 14, 2021. 

Lance T. Gant, 

Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2021–15469 Filed 7–21–21; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2021–0576; Project 

Identifier 2019–CE–008–AD] 

RIN 2120–AA64 

Airworthiness Directives; Pacific 

Aerospace Limited 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 Pacific Aerospace Limited 

Model 750XL airplanes. This proposed 

AD was prompted by mandatory 

continuing airworthiness information 

(MCAI) originated by an aviation 

authority of another country to identify 

and correct an unsafe condition on an 

aviation product. The MCAI describes 

the unsafe condition as installation of 

the wing leading edge tank fuel pickup 

assembly in a pre-stressed condition, 

which could cause cracks in the wing 

spar web or the fuel pickup assembly 

pipe. This proposed AD would require 

inspecting the angle of the support 

bracket on the wing leading edge tank 

fuel pickup assembly and taking any 

necessary 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 September 7, 

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 AD, 

contact the Civil Aviation Authority of 

New Zealand, Level 15, Asteron Centre, 

55 Featherston Street, Wellington 6011; 

phone: +64 4 560 9400; fax: +64 4 569 

202; email: info@caa.govt.nz. 

You may view this service 

information at the FAA, Airworthiness 

Products Section, Operational Safety 

Branch, 901 Locust, Kansas City, MO 

64106. For information on the 

availability of this material at the FAA, 

call (816) 329–4148. 

Examining the AD Docket 

You may examine the AD docket at 

https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2021–0576; 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, the MCAI, any comments 

received, and other information. The 

street address for Docket Operations is 

listed above. Comments will be 

available in the AD docket shortly after 

receipt. 

FOR FURTHER INFORMATION CONTACT: 

Mike Kiesov, Aviation Safety Engineer, 

General Aviation & Rotorcraft Section, 

International Validation Branch, FAA, 

901 Locust, Room 301, Kansas City, MO 

64106; phone: (816) 329–4144; fax: (816) 

329–4090; email: mike.kiesov@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–2021–0576; Project Identifier 

2019–CE–008–AD’’ 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 this 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 Mike Kiesov, Aviation 

Safety Engineer, General Aviation & 

Rotorcraft Section, International 

Validation Branch, FAA, 901 Locust, 

Room 301, Kansas City, MO 64106. Any 

commentary that the FAA receives 

which is not specifically designated as 

CBI will be placed in the public docket 

for this rulemaking. 

Background 

The Civil Aviation Authority (CAA), 

which is the aviation authority for New 

Zealand, has issued AD No. DCA/ 


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