40378 Federal Register / Vol. 86, No. 142 / Wednesday, July 28, 2021 / Proposed Rules 

installed. These 53 airplanes are 

registered to twenty (20) entities. 

Twenty (20) airplanes are registered to 

the United States Government entities, 

including the U.S. Customs and Border 

Protection, which operates thirteen (13) 

of these airplanes. The FAA determined 

that these government entities are not 

small businesses or other forms of small 

entity. 

The remaining thirty-three (33) 

airplanes are owned and operated by 

sixteen (16) private entities. All of these 

private entities fall under the 481112 

NAICS Code (Scheduled Freight Air 

Transportation) with a small business 

size standard of a maximum of 1,500 

employees to be considered small 

business. 

Six (6) of these thirty-three (33) 

airplanes are registered to Lynden Air 

Cargo, LLC, affiliated with the Lynden 

Incorporated, which, with 2,500 

employees on its payroll, is not a small 

entity per the SBA definition. The FAA 

considered all other entities that own 

and operate similar airplanes as small 

entities since they all employ less than 

1,500 employees. Therefore, the FAA 

estimated that this proposed AD would 

impact fifteen (15) small entities. 

5. Projected Reporting, Recordkeeping, 

and Other Compliance Requirements 

There are no reporting or 

recordkeeping costs with this proposed 

AD. However, the FAA estimated that 

there would be compliance costs due to 

the proposed requirements as discussed 

below. 

Using the compliance cost estimate 

that Lynden Air Cargo LLC provided in 

its public comment to the proposed AD 

($9,190 to inspect all propeller blades 

installed on each propeller, or $36,760 

to inspect an airplane with four (4) 

propellers), the FAA calculated the total 

compliance costs of this AD on fifteen 

(15) small businesses that own and 

operate twenty-seven (27) airplanes at 

$992,520 ($36,760 × 27). Eight (8) small 

businesses that own and operate one 

airplane would incur $36,760. The 

compliance costs of one small entity 

with five (5) airplanes would be 

$183,800. The average compliance costs 

of this AD on small entities would be 

$66,168 ($992,520/15). 

The FAA estimated the revenue 

impact of complying with this proposed 

AD’s requirements on these 15 small 

entities would vary from under 1 

percent (0.12 percent) of affected 

companies’ annual revenues to 

approximately 2 percent (1.69 percent) 

of their annual revenues. 

To the extent that small entities 

provide more unique services or serve 

markets with less competition, they may 

also be able to pass on costs in the form 

of price increases. However, the FAA 

assumed that none of these small 

entities would be able to pass these 

compliance costs to their customers in 

terms of higher prices. 

6. Significant Alternatives Considered 

The FAA did not find any significant 

regulatory alternatives to the proposed 

AD that would still accomplish the 

safety objectives of this proposed AD. 

Issued on July 21, 2021. 

Gaetano A. Sciortino, 

Deputy Director for Strategic Initiatives, 

Compliance & Airworthiness Division, 

Aircraft Certification Service. 

[FR Doc. 2021–15979 Filed 7–27–21; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2018–0689; Product 

Identifier 2018–CE–016–AD] 

RIN 2120–AA64 

Airworthiness Directives; Gulfstream 

Aerospace Corporation Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Proposed rule; withdrawal. 

SUMMARY: The FAA is withdrawing a 

notice of proposed rulemaking (NPRM) 

that proposed to adopt a new 

airworthiness directive (AD) for certain 

Gulfstream Aerospace Corporation 

(Gulfstream) Models G–IV and GIV–X 

airplanes. The NPRM was prompted by 

reports of disbonding and surface 

cracking of the composite aft pressure 

bulkhead. The NPRM proposed to 

require inspecting the forward and aft 

surfaces of the pressure bulkhead 

composite panels for damage and 

repairing any damage found. Since 

issuance of the NPRM, the FAA has 

determined that there is not an unsafe 

condition. Accordingly, the NPRM is 

withdrawn. 

DATES: As of July 28, 2021, the proposed 

rule, which published in the Federal 

Register on July 27, 2018 (83 FR 35568), 

is withdrawn. 

ADDRESSES: 

Examining the AD Docket 

You may examine the AD docket at 

https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2018–0689; 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 

AD action, any comments received, and 

other information. The street address for 

Docket Operations is U.S. Department of 

Transportation, Docket Operations, 

M–30, West Building Ground Floor, 

Room W12–140, 1200 New Jersey 

Avenue SE, Washington, DC 20590. 

FOR FURTHER INFORMATION CONTACT: 

William O. Herderich, Aviation Safety 

Engineer, Atlanta ACO Branch, FAA, 

1701 Columbia Avenue, College Park, 

GA 30337; phone: (404) 474–5547; fax: 

(404) 474–5605; email: 

william.o.herderich@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Background 

The FAA issued an NPRM that 

proposed to amend 14 CFR part 39 by 

adding an AD that would apply to 

certain serial-numbered Gulfstream 

Models G–IV and GIV–X airplanes. The 

NPRM published in the Federal 

Register on July 27, 2018 (83 FR 35568). 

The NPRM was prompted by reports of 

disbonding and accompanying surface 

cracking of the composite aft pressure 

bulkhead. The NPRM stated that this 

condition, if not addressed, could result 

in structural failure of the aft pressure 

bulkhead and loss of cabin pressure. 

In the NPRM, the FAA proposed to 

require a one-time inspection of the 

forward and aft surfaces of the pressure 

bulkhead composite panels for damage 

and repairing any damage found. 

Actions Since the NPRM Was Issued 

After issuance of the NPRM, the FAA 

reviewed a Gulfstream safety assessment 

and determined that a bulkhead with 

disbonding is still capable of carrying 

operational loads. If the affected 

airplanes are capable of carrying 

operational loads without failure, then 

there is no unsafe condition. 

Based on the above information, the 

FAA has determined that AD action is 

not warranted and the proposal should 

be withdrawn. 

Comments 

The FAA received comments from 

Gulfstream, the European Union 

Aviation Safety Agency (EASA), and an 

individual commenter. 

Requests 

Gulfstream requested that the FAA 

clarify language throughout the 

preamble and unsafe condition 

statement. EASA requested the FAA add 

a requirement to repeat the inspection. 

The individual commenter requested 

the FAA clarify the affected serial 

numbers. 

The FAA acknowledges these 

comments. However, because the NPRM 


khammond on DSKJM1Z7X2PROD with PROPOSALS
Federal Register / Vol. 86, No. 142 / Wednesday, July 28, 2021 / Proposed Rules 40379 

is being withdrawn, the commenters’ 

requests are no longer necessary. 

Withdrawal of the NPRM constitutes 

only such action and does not preclude 

the FAA from further rulemaking on 

this issue, nor does it commit the FAA 

to any course of action in the future. 

Regulatory Findings 

Since this action only withdraws an 

NPRM, it is neither a proposed AD nor 

a final rule. This action, therefore, is not 

covered under Executive Order 12866 or 

the Regulatory Flexibility Act. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation 

safety, Incorporation by reference, 

Safety. 

The Withdrawal 

■ Accordingly, the notice of proposed 

rulemaking, which published in the 

Federal Register on July 27, 2018 (83 FR 

35568), is withdrawn. 

Issued on July 21, 2021. 

Gaetano A. Sciortino, 

Deputy Director for Strategic Initiatives, 

Compliance & Airworthiness Division, 

Aircraft Certification Service. 

[FR Doc. 2021–15952 Filed 7–27–21; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2021–0157; Project 

Identifier AD–2020–00483–T] 

RIN 2120–AA64 

Airworthiness Directives; Learjet Inc. 

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 Learjet Inc. (Learjet) Model 45 

airplanes. This proposed AD was 

prompted by reports of corrosion found 

on the upper surface of the lower center 

wing mid spar splice plate. This 

proposed AD would require repetitively 

inspecting the center wing area for 

corrosion and deterioration of protective 

treatments, removing any corrosion, and 

treating any deteriorated areas. 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 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 Learjet Inc., One 

Learjet Way, Wichita, KS 67209; phone: 

(316) 946–2000; email: ac.ict@

aero.bombardier.com; website: https://

businessaircraft.bombardier.com/en/ 

aircraft/Learjet.html. 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. 

Examining the AD Docket 

You may examine the AD docket at 

https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2021–0157; 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: Tara 

Shawn, Aviation Safety Engineer, 

Wichita ACO Branch, FAA, 1801 

Airport Road, Wichita, KS 67209; 

phone: (316) 946–4141; fax: (316) 946– 

4107; email: tara.shawn@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–2021–0157; Project Identifier AD– 

2020–00483–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 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 Tara Shawn, Aviation 

Safety Engineer, Wichita ACO Branch, 

FAA, 1801 Airport Road, Wichita, KS 

67209. Any commentary that the FAA 

receives which is not specifically 

designated as CBI will be placed in the 

public docket for this rulemaking. 

Background 

In December 2018, the FAA received 

a report from Learjet of corrosion found 

in the center wing area of a Model 45 

(Learjet 45) airplane. Exfoliating 

corrosion was found on the upper 

surface of the lower center wing mid 

spar splice plate during unrelated 

maintenance. The corrosion appeared to 

extend half way through the thickness 

of the splice plate. Since the initial 

report, the FAA has received 23 

additional reports of corrosion from 

Learjet. The FAA determined areas of 

the wing center section are not sealed 

against the elements; in addition, the 

fuselage has drain holes that allow 

condensation to drain into the center 

wing. The accumulation and retention 

of moisture in the center wing section 

may lead to corrosion. This condition, if 

not addressed, could result in failure of 

the wing centerline joint and lead to 

partial wing separation with consequent 

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 


khammond on DSKJM1Z7X2PROD with PROPOSALS