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

40460 

Vol. 87, No. 129 

Thursday, July 7, 2022 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2022–0588; Project 

Identifier AD–2022–00114–T] 

RIN 2120–AA64 

Airworthiness Directives; The Boeing 

Company Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to 

supersede Airworthiness Directive (AD) 

2021–14–20, which applies to all The 

Boeing Company Model 737 airplanes. 

AD 2021–14–20 requires repetitive 

functional tests of the cabin altitude 

pressure switches, and on-condition 

actions, including replacement, if 

necessary. AD 2021–14–20 also requires 

reporting test results. Since the FAA 

issued AD 2021–14–20, data collected 

from the reports required by AD 2021– 

14–20 revealed that the switches were 

subject to false test failures due to lack 

of clear instructions for setup of the test 

adapters during the functional tests. 

This proposed AD would retain the 

repetitive functional tests and oncondition actions, and specify certain 

adapter requirements for the functional 

tests. 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 22, 

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–2022–0588; 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: 

Nicole Tsang, Aerospace Engineer, 

Cabin Safety and Environmental 

Systems Section, FAA, Seattle ACO 

Branch, 2200 South 216th St., Des 

Moines, WA 98198; phone and fax: 206– 

231–3959; email: Nicole.S.Tsang@

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–2022–0588; Project Identifier AD– 

2022–00114–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 proposed 

AD. 

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 Nicole Tsang, 

Aerospace Engineer, Cabin Safety and 

Environmental Systems Section, FAA, 

Seattle ACO Branch, 2200 South 216th 

St., Des Moines, WA 98198; phone and 

fax: 206–231–3959; email: 

Nicole.S.Tsang@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 

The FAA issued AD 2021–14–20, 

Amendment 39–21647 (86 FR 38214, 

July 20, 2021) (AD 2021–14–20), for all 

The Boeing Company Model 737 

airplanes. AD 2021–14–20 was 

prompted by reports of latent failures of 

the cabin altitude pressure switches. AD 

2021–14–20 requires repetitive 

functional tests of the pressure switches, 

and on-condition actions, including 

replacement, if necessary. The agency 

issued AD 2021–14–20 to address the 

unexpectedly high rate of latent failure 

of both pressure switches on the same 

airplane, which could result in the 

cabin altitude warning system not 

activating if the cabin altitude exceeds 

10,000 feet, resulting in hypoxia of the 

flightcrew and loss of control of the 

airplane. 

Actions Since AD 2021–14–20 Was 

Issued 

Since the FAA issued AD 2021–14– 

20, Boeing, Eaton Aerospace (the cabin 

altitude warning switch supplier) and 

the FAA analyzed data collected from 

the reports required by AD 2021–14–20. 

That data revealed that the switches 

were subject to false test failures due to 

lack of clear instructions for setup of the 

test adapters during the functional tests. 


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Federal Register / Vol. 87, No. 129 / Thursday, July 7, 2022 / Proposed Rules 40461 

For most of the switches that were 

tested by the supplier after failing a 

functional test, no fault was found in 

the switches. Instead, it was determined 

that if a test adapter not meeting certain 

criteria (threads having a full thread 

depth of no greater than 0.438 inches 

(1.113 cm) and an overall length less 

than 0.500 inches (1.270 cm)) is 

connected to the cabin altitude warning 

switch, false failures may occur during 

the functional test. Based on this 

analysis, Boeing revised its airplane 

maintenance manual (AMM) 

procedures, which provide guidance for 

performing the functional test, to 

specify criteria for the adapters and 

matching hoses (those that are 25 feet to 

40 feet (7.62 to 12.19 meters) long, with 

#4 AN fitting to the adapter and quick 

disconnect (if applicable) to the air data 

test set). The matching hose criteria 

ensures there is a connection between 

the pressure switch and the air data test 

set. The FAA determined that AD 2021– 

14–20 should be superseded to ensure 

the functional tests are performed using 

the correct adapters to avoid false 

failure results. In addition, the FAA 

determined that sufficient data has been 

received regarding the cause of the 

failures of the cabin altitude pressure 

switches. Therefore, the reporting 

required by AD 2021–14–20 is no longer 

needed. This proposed AD would 

therefore retain the repetitive functional 

tests and on-condition actions, and 

specify certain adapter requirements for 

the functional tests. 

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. 

Proposed AD Requirements in This 

NPRM 

This proposed AD would retain 

certain requirements of AD 2021–14–20. 

This proposed AD would continue to 

require repetitive functional tests of the 

pressure switches having part number 

214C50–2, and on-condition actions, 

including replacement, if necessary. 

This proposed AD would require using 

adapters and matching hoses meeting 

certain criteria when performing the 

functional tests, as specified in figure 1 

to paragraph (g) of this AD. This 

proposed AD would also eliminate the 

reporting required by AD 2021–14–20. 

Effect of Certain Installation Procedures 

on Accomplishment of AD 

Requirements 

The FAA issued AD 2015–21–11, 

Amendment 39–18304 (80 FR 65927, 

October 28, 2015) (AD 2015–21–11) 

applicable to certain Model 737–100, 

–200, –200C, –300, –400, –500, –600, 

–700, –700C, –800, –900, and –900ER 

series airplanes. AD 2015–21–11 

requires, among other actions, the 

installation of a redundant cabin 

altitude pressure switch in accordance 

with specified Boeing service 

information. The FAA has since 

approved numerous supplemental type 

certificates (STCs) and other means for 

installing the redundant pressure 

switch. As a result of its oversight of 

these newly-installed switches, the FAA 

has determined that use of approved 

maintenance procedures for the cabin 

altitude pressure switch functional test 

other than the task cards specified in 

Note 1 to paragraph (g) of this AD, is 

acceptable for the functional test, 

provided the adapter meets the criteria 

specified in paragraph (g) of this AD. 

Therefore, those other procedures do 

not require approval of an alternative 

method of compliance (AMOC). 

Costs of Compliance 

The FAA estimates that this AD, if 

adopted as proposed, would affect 2,693 

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 

Functional test ......................... 1 work-hour × $85 per hour = $85 per test .... * $ $85 per test .... $228,905 per test. 

* If the operator needs to buy an adapter, the FAA estimates the adapter could cost up to $3,644. The FAA has no way of determining the 

number of operators that might need to purchase an adapter. 

The FAA estimates the following 

costs to do any necessary on-condition 

actions that would be required based on 

the results of the functional test. The 

FAA has no way of determining the 

number of aircraft that might need these 

actions: 

ON-CONDITION COSTS

Action Labor cost Parts cost Cost per 

product 

Switch replacement ...................................................... 1 work-hour × $85 per hour = $85 ............................... $1,278 $1,363 

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 has 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. 


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40462 Federal Register / Vol. 87, No. 129 / Thursday, July 7, 2022 / Proposed Rules 

For the reasons discussed above, I 

certify that the 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: 

■ a. Removing Airworthiness Directive 

(AD) AD 2021–14–20, Amendment 39– 

21647 (86 FR 38214, July 20, 2021), and 

■ b. Adding the following new AD: 

The Boeing Company: Docket No. FAA– 

2022–0588; Project Identifier AD–2022– 

00114–T. 

(a) Comments Due Date 

The FAA must receive comments on this 

airworthiness directive (AD) action by 

August 22, 2022. 

(b) Affected ADs 

This AD replaces AD 2021–14–20, 

Amendment 39–21647 (86 FR 38214, July 20, 

2021) (AD 2021–14–20). 

(c) Applicability 

This AD applies to all The Boeing 

Company Model 737–100, –200, –200C, 

–300, –400, –500, –600, –700, –700C, –800, 

–900, and –900ER series airplanes and Model 

737–8, 737–9, and 737–8200 airplanes, 

certificated in any category. 

(d) Subject 

Air Transport Association (ATA) of 

America Code 21, Air conditioning. 

(e) Unsafe Condition 

This AD was prompted by reports of latent 

failures of the cabin altitude pressure 

switches, and the determination that using 

certain adapters while performing a 

functional test may lead to false failures of 

the cabin altitude pressure switches. The 

FAA is issuing this AD to address the 

unexpectedly high rate of latent failure of 

both pressure switches on the same airplane 

which could result in the cabin altitude 

warning system not activating if the cabin 

altitude exceeds 10,000 feet, resulting in 

hypoxia of the flightcrew, and loss of control 

of the airplane. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Repetitive Functional Tests 

(1) At the latest of the times specified in 

paragraphs (g)(1)(i) through (iii) of this AD, 

perform a functional test of the cabin altitude 

pressure switches having part number 

214C50–2, using an adapter as specified in 

figure 1 to paragraph (g) of this AD, or an 

equivalent adapter, and matching hose to 

connect to the cabin altitude warning switch. 

Repeat the functional test thereafter at 

intervals not to exceed 2,000 flight hours. If, 

during any functional test, any cabin altitude 

pressure switch fails to activate at an altitude 

of between 9,000 and 11,000 feet, replace the 

switch before further flight. 

(i) Within 2,000 flight hours since the last 

functional test of the cabin altitude pressure 

switches. 

(ii) Prior to the accumulation of 2,000 total 

flight hours on the airplane. 

(iii) Within 90 days after the effective date 

of this AD. 

(2) Adapters are considered to be 

equivalent as long as the mating side with the 

switch meets the specifications in either 

paragraph (g)(2)(i) or (ii) of this AD: 

(i) Greater than or equal to 0.265 inches 

(0.673 cm) X 7/16–20–UNJF–3A and less 

than or equal to 0.438 inches (1.113 cm) X 

7/16–20–UNJF–3A for the flareless end; or 

(ii) Less than or equal to 0.5 inches (1.27 

cm) total with greater than or equal to 0.265 

inches (0.673 cm) X 7/16–20–UNJF–3A 

thread for AN4 flared end. 

BILLING CODE 3510–22–P 


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Figure 1 to paragraph (g) of this AD -Functional Test Adapters 

Use one of the following adapters, or an equivalent adapter, and matching hose to 

connect to the cabin altitude warning switch: 

(1) SAE J514 part number (PIN) 070220 90 Degree Straight Thread Elbow and 

appropriate sized O-ring (Preferred). 

• Use a Barfield Pitot Hose, or equivalent 25 feet (7.62 m) to 40 feet (12.19 m) long 

hose, with #4 AN fitting to the adapter and quick disconnect (if applicable) to the air 

data test set. 

• Make sure that the flat side of the adapter is connected with the cabin altitude 

warning switch. 

NOTE: Do not connect the flared side of the adapter with the cabin altitude warning 

switch. Connecting the flared side of the adapter with the cabin altitude warning 

switch may bottom out the cabin altitude warning switch, resulting in false test 

results. 

(2) SAE J514 PIN 070320 45 Degree Straight Thread Elbow and appropriate sized Oring (Preferred). 

• Use a Barfield Pitot Hose, or equivalent 25 feet (7.62 m) to 40 feet (12.19 m) long 

hose, with #4 AN fitting to the adapter and quick disconnect (if applicable) to the 

air data test set. 

• Make sure that the flat side of the adapter is connected with the cabin altitude 

warning switch. 

NOTE: Do not connect the flared side of the adapter with the cabin altitude warning 

switch. Connecting the flared side of the adapter with the cabin altitude warning 

switch may bottom out the cabin altitude warning switch, resulting in false test 

results. 

(3) SAE J514 PIN 070120 Straight Thread Connector Short and appropriate sized Oring (Preferred). 

• Use a Barfield Pitot Hose, or equivalent 25 feet (7.62 m) to 40 feet (12.19 m) long 

hose, with #4 AN fitting to the adapter and quick disconnect (if applicable) to the 

air data test set. 

• Make sure that the flat side of the adapter is connected with the cabin altitude 

warning switch. 

NOTE: Do not connect the flared side of the adapter with the cabin altitude warning 

switch. Connecting the flared side of the adapter with the cabin altitude warning 

switch may bottom out the cabin altitude warning switch, resulting in false test 

results. 

( 4) AS2 l 900-4 ( or MS2 l 900-4) Flareless Tube to Flared Tube Adapter and appropriate 

sized O-ring (Preferred). 

• Use a Barfield Pitot Hose, or equivalent 25 feet (7.62 m) to 40 feet (12.19 m) long 

hose, with #4 AN fitting to the adapter and quick disconnect (if applicable) to the 

air data test set. 
40464 Federal Register / Vol. 87, No. 129 / Thursday, July 7, 2022 / Proposed Rules 

Note 1 to paragraph (g): Additional 

guidance for performing the functional test 

required by paragraph (g) of this AD can be 

found in 737–200 Airplane Maintenance 

Manual (AMM) 21–33–11/501, 737CL AMM 

TASK CARD 31–026–01–01, 737CL AMM 

TASK CARD 31–010–01–01, 737NG AMM 

TASK CARD 31–020–00–01, and 737MAX 

AMM TASK CARD 31–020–00–01, and other 

approved maintenance procedures. 

(h) Minimum Equipment List Provisions 

If any cabin altitude warning switch fails 

any functional test as required by this AD, 

the airplane may be operated as specified in 

the operator’s existing FAA-approved MEL, 

provided provisions that specify operating 

the airplane at a flight altitude at or below 

10,000 feet mean sea level (MSL) with the 

cabin altitude warning system inoperative are 

included in the operator’s existing FAAapproved MEL. 

(i) 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 responsible Flight 

Standards 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 (j)(1) of 

this AD. Information may be emailed to 9- 

ANM-Seattle-ACO-AMOC-Requests@faa.gov. 

(2) Before using any approved AMOC, 

notify your appropriate principal inspector, 

or lacking a principal inspector, the manager 

of the responsible Flight Standards Office. 

(3) An AMOC that provides an acceptable 

level of safety may be used for any repair, 

modification, or alteration required by this 

AD if it is approved by The Boeing Company 

Organization Designation Authorization 

(ODA) that has been authorized by the 

Manager, Seattle ACO Branch, FAA, to make 

those findings. To be approved, the repair 

method, modification deviation, or alteration 

deviation must meet the certification basis of 

the airplane, and the approval must 

specifically refer to this AD. 

(j) Related Information 

(1) For more information about this AD, 

contact Nicole Tsang, Aerospace Engineer, 

Cabin Safety and Environmental Systems 

Section, FAA, Seattle ACO Branch, 2200 

South 216th St., Des Moines, WA 98198; 

phone and fax: 206–231–3959; email: 

Nicole.S.Tsang@faa.gov. 

(2) For service information identified in 

this AD that is not incorporated by reference, 

contact Boeing Commercial Airplanes, 

Attention: Contractual & Data Services 

(C&DS), 2600 Westminster Blvd., MC 110– 

SK57, Seal Beach, CA 90740–5600; telephone 

562–797–1717; internet https://

www.myboeingfleet.com. 

Issued on May 16, 2022. 

Gaetano A. Sciortino, 

Deputy Director for Strategic Initiatives, 

Compliance & Airworthiness Division, 

Aircraft Certification Service. 

[FR Doc. 2022–13980 Filed 7–6–22; 8:45 am] 

BILLING CODE 4910–13–C 

FEDERAL COMMUNICATIONS 

COMMISSION 

47 CFR Parts 73 and 74 

[GN Docket No. 16–142; FCC 22–47; FR ID 

93764] 

Authorizing Permissive Use of the 

‘‘Next Generation’’ Broadcast 

Television Standard 

AGENCY: Federal Communications 

Commission. 

ACTION: Proposed rule. 

SUMMARY: In this document, the 

Commission seeks comment on the state 


khammond on DSKJM1Z7X2PROD with PROPOSALSEP07JY22.001</GPH>

• Make sure that the flat side of the adapter is connected with the cabin altitude 

warning switch. 

NOTE: Do not connect the flared side of the adapter with the cabin altitude warning 

switch. Connecting the flared side of the adapter with the cabin altitude warning 

switch may bottom out the cabin altitude warning switch, resulting in false test 

results. 

(5) PIN JUD321 Hose Fitting with MS28778-4 O-ring (Eaton Aerospace LLC, Bethel, 

CT 02750) (Preferred). 

• Use a Barfield Pitot Hose, or equivalent 25 feet (7.62 m) to 40 feet (12.19 m) long 

hose, with #4 AN fitting to the adapter and quick disconnect (if applicable) to the 

air data test set. 

(6) AN807-4D (or AS5180D04 or AS5180W04) Tube to Hose Adapter, AN924-4 nut 

and appropriate sized O-ring ( on the mating side with the switch) and spacer or 

washers (Alternate). 

NOTE: This adapter can be used if the steps below are carefully followed. This 

adapter is not preferred because if the AN924-4 nut is not connected carefully as 

recommended below, this may bottom out the cabin altitude warning switch, 

resulting in false test results. 

• Use a Barfield Pitot Hose, or equivalent 25 feet (7.62 m) to 40 feet (12.19 m) long 

hose, with quick disconnect (if applicable) to the air data test set. 

• Make sure that the thread length, including fitting end after the installation of 

AN924-4 nut and appropriate sized 7/16 spacer or washers, is less than 0.5 inch 

(1.270 cm) to avoid false test results.