Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules 86073 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2023–1993; Project 

Identifier AD–2023–00129–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) 

2020–03–20, which applies to certain 

The Boeing Company Model MD–11, 

MD–11F, and 717–200 airplanes, all 

Model 737–8 and 737–9 airplanes, all 

Model 737–600, –700, –700C, –800, 

–900, and –900ER series airplanes, 

certain Model 747–400 and 747–400F 

series airplanes, certain Model 757 and 

767 airplanes, and all Model 777 

airplanes. AD 2020–03–20 requires 

revising the existing airplane flight 

manual (AFM) to include a limitation to 

prohibit operations that require less 

than 0.3 required navigational 

performance (RNP) within a specified 

area for airplanes having a certain multimode receiver (MMR) with certain 

software installed. Since the FAA issued 

AD 2020–03–20, the agency received 

reports from Boeing of simultaneous 

MMR resets related to an error in 

calculating Coordinated Universal Time 

(UTC). This proposed AD would 

continue to require the actions in AD 

2020–03–20 and would also require 

installing certain MMR operational 

software (OPS). 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 January 26, 

2024. 

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 

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. 

AD Docket: You may examine the AD 

docket at regulations.gov under Docket 

No. FAA–2023–1993; 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. 

Material Incorporated by Reference: 

• For service information identified 

in this NPRM, 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; website 

myboeingfleet.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. It is also available at 

regulations.gov by searching for and 

locating Docket No. FAA–2023–1993. 

FOR FURTHER INFORMATION CONTACT: 

Jeffrey W. Palmer, Aviation Safety 

Engineer, FAA, 2200 South 216th St., 

Des Moines, WA 98198; phone: 562– 

627–5351; jeffrey.w.palmer@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–2023–1993; Project Identifier AD– 

2023–00129–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 

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 Jeffrey W. Palmer, 

Aviation Safety Engineer, FAA, 2200 

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

phone: 562–627–5351; 

jeffrey.w.palmer@faa.gov. Any 

commentary that the FAA receives that 

is not specifically designated as CBI will 

be placed in the public docket for this 

rulemaking. 

Background 

The FAA issued AD 2020–03–20, 

Amendment 39–19844 (85 FR 8717, 

February 18, 2020) (AD 2020–03–20), 

for The Boeing Company Model MD–11 

and MD–11F airplanes modified by 

supplemental type certificate (STC) 

ST01895WI; Model 717–200 airplanes 

modified by STC ST04416AT; all Model 

737–8 and 737–9 airplanes; all Model 

737–600, –700, –700C, –800, –900, and 

–900ER series airplanes; Model 747–400 

and 747–400F series airplanes modified 

by STC ST01892WI; Model 757–200, 

–200PF, –200CB, and –300 series 

airplanes modified by STC ST04436AT; 

Model 767–200, –300, –300F, –400ER, 

and –2C series airplanes modified by 

STC ST04436AT or ST01883WI; and all 

Model 777–200, –200LR, –300, –300ER, 

and 777F series airplanes. 

AD 2020–03–20 was prompted by 

reports of the loss of global positioning 

system (GPS) data or degraded GPS 

positional accuracy while using a 

certain MMR with certain Collins MMR 

software installed. When an airplane is 

within a specific geographic region, the 

software is failing to map the computed 

ionospheric pierce point to the correct 

hemisphere. As a result, AD 2020–03– 

20 requires airplanes with a certain 

MMR with certain software installed to 

revise the existing AFM to include a 

limitation to prohibit operations that 

require less than 0.3 RNP within the 

specified geographic area. The agency 

issued AD 2020–03–20 to address the 

loss of GPS data and degraded GPS 

positional accuracy, which, during a 

high-precision approach with this GPS 

error, could result in controlled flight 

into terrain. 


ddrumheller on DSK120RN23PROD with PROPOSALS1
86074 Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules 

Actions Since AD 2020–03–20 Was 

Issued 

Since the FAA issued AD 2020–03– 

20, the FAA received reports from 

Boeing indicating there is an MMR 

software error that results in an MMR 

reset after a leap-second, which is 

occasionally applied to UTC. If the 

software calculation error occurs on all 

MMRs that are powered on at that time, 

there could be simultaneous loss of all 

MMR-based functions on all affected 

airplanes. If an affected airplane is in 

flight phase when this calculation error 

occurs, the loss of all MMR functions 

would result in increased flightcrew 

workload, as the flightcrew would 

reduce automation and switch to 

operating under visual flight rules, 

which requires contacting air traffic 

control (ATC) for direction and support. 

In the event of multiple airplanes 

simultaneously experiencing loss of 

MMR function in instrument 

meteorological conditions during 

landing or takeoff, this would result in 

increased ATC workload and 

consequent reduction in airplane 

spacing, which could result in a mid-air 

collision. 

In addition, Boeing has developed 

new software that addresses both the 

unsafe condition identified in AD 2020– 

03–20 (software that fails to map the 

computed ionospheric pierce point to 

the correct hemisphere) and the 

additional unsafe condition identified 

in this proposed AD (software error that 

results in an MMR reset after a leapsecond). Installing the new software 

would eliminate the need for the AFM 

revision required by AD 2020–03–20. 

FAA’s Determination 

The FAA is issuing this NPRM after 

determining that the unsafe conditions 

described previously are likely to exist 

or develop on other products of the 

same type design. 

Related Service Information Under 1 

CFR Part 51 

The FAA reviewed the following 

Boeing requirements bulletins: 

• Boeing Alert Requirements Bulletin 

737–34A3572 RB, dated October 15, 

2020. 

• Boeing Alert Requirements Bulletin 

737–34A3573 RB, dated August 5, 2020. 

• Boeing Alert Requirements Bulletin 

777–34A0385 RB, Revision 1, dated 

March 8, 2021. 

This service information specifies 

procedures for installation of MMR OPS 

part number (P/N) COL4C–0087–0003 

(or later-approved software P/N) in 

MMR 1 and MMR 2, installation of 

MMR option selection software (OSS) P/ 

N BCG27–U000–0730 or BCG48–U000– 

05W9, and software configuration 

checks. This service information also 

specifies taking concurrent actions, 

including replacement of MMRs, 

replacement of GPS antennas, and 

installation of additional software. 

These documents are distinct since 

they apply to different airplane models 

and 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. 

Proposed AD Requirements in This 

NPRM 

This proposed AD would retain all 

requirements of AD 2020–03–20. This 

proposed AD would also require 

accomplishing the actions specified in 

the service information described 

previously, except as discussed under 

‘‘Differences Between this Proposed AD 

and the Service Information.’’ For 

information on the procedures and 

compliance times, see this service 

information at regulations.gov by 

searching for and locating Docket No. 

FAA–2023–1993. For airplanes for 

which the service information is not 

applicable, this proposed AD would 

require installing MMR OPS P/N 

COL4C–0087–0003 (or later-approved 

software version) and conducting a 

software configuration check, both of 

which must be done in accordance with 

a method approved by the Manager, 

AIR–520, Continued Operational Safety 

Branch, FAA. 

Differences Between This Proposed AD 

and the Service Information 

Where the service information 

specifies installing MMR OSS P/N 

BCG27–U000–0730 or BCG48–U000– 

05W9, this proposed AD would not 

require that action. Those MMR OSS 

part numbers are not used to calculate 

position nor time functions; therefore, 

the installation of those MMR OSS part 

numbers is not required for addressing 

the unsafe condition. 

Costs of Compliance 

The FAA estimates that this AD, if 

adopted as proposed, would affect 409 

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 

AFM revision (retained action from 

AD 2020-03-20).

1 work-hour × $85 per hour = $85 $0 $85 $34,765. 

Software installation and check 

(new proposed action).

2 work-hours × $85 per hour = 

$170.

265 435 $177,915. 

Concurrent actions ......................... 5 work-hours × $85 = $425 ........... 795 1,220 Up to $498,980.* 

* Not all airplanes would be required to do the concurrent actions. However, the FAA does not have an estimate of how many airplanes are in 

a configuration that would require concurrent actions. 

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 


ddrumheller on DSK120RN23PROD with PROPOSALS1
Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules 86075 

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 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) 2020–03–20, Amendment 39– 

19844 (85 FR 8717, February 18, 2020), 

and 

■ b. Adding the following new AD: 

The Boeing Company: Docket No. FAA– 

2023–1993; Project Identifier AD–2023– 

00129–T. 

(a) Comments Due Date 

The FAA must receive comments on this 

airworthiness directive (AD) by January 26, 

2024. 

(b) Affected ADs 

This AD replaces AD 2020–03–20, 

Amendment 39–19844 (85 FR 8717, February 

18, 2020) (AD 2020–03–20). 

(c) Applicability 

This AD applies to The Boeing Company 

airplanes, certificated in any category, as 

identified in paragraphs (c)(1) through (9) of 

this AD. 

(1) Model MD–11 and MD–11F airplanes 

modified by supplemental type certificate 

(STC) ST01895WI. 

(2) Model 717–200 airplanes modified by 

STC ST04416AT. 

(3) All Model 737–8 and 737–9 airplanes. 

(4) All Model 737–600, –700, –700C, –800, 

–900, and –900ER series airplanes. 

(5) Model 747–400 and 747–400F series 

airplanes modified by STC ST01892WI. 

(6) Model 757–200, –200PF, –200CB, and 

–300 series airplanes modified by STC 

ST04436AT. 

(7) Model 767–200, –300, –300F, –400ER, 

and –2C series airplanes modified by STC 

ST04436AT or ST01883WI. 

(8) All Model 777–200, –200LR, –300, and 

–300ER series airplanes. 

(9) All Model 777F series airplanes. 

(d) Subject 

Air Transport Association (ATA) of 

America Code 34, Navigation. 

(e) Unsafe Condition 

This AD was prompted by reports of the 

loss of global positioning system (GPS) data 

or degraded GPS positional accuracy and 

additional reports of an error in calculating 

Coordinated Universal Time (UTC) while 

using a certain multi-mode receiver (MMR) 

with certain software installed. The FAA is 

issuing this AD to address loss of GPS data 

and degraded GPS positional accuracy, 

which, during a high-precision approach 

with this GPS error, could result in 

controlled flight into terrain, and to address 

UTC calculation errors that could result in 

simultaneous MMR resets on multiple 

airplanes, increased air traffic control 

workload, and consequent reduction in 

airplane separation and potential for mid-air 

collision. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Retained Airplane Flight Manual (AFM) 

Revision, With No Changes 

This paragraph restates the requirements of 

paragraph (g) of AD 2020–03–20, with no 

changes. For airplanes equipped with Collins 

GLU–2100 MMR, part number (P/N) 822– 

2532–100, having any applicable GLU–2100 

operational software (OPS) identified in 

figure 1 to paragraph (g) of this AD installed: 

At the applicable time specified in 

paragraphs (g)(1) and (2) of this AD, revise 

the limitations or certificate limitations 

section, as applicable, of the existing AFM to 

include the information specified in figure 2 

to paragraph (g) of this AD and revise the 

procedures or normal procedures section, as 

applicable, of the existing AFM to include 

the information specified in figure 3 to 

paragraph (g) of this AD. This may be done 

by inserting a copy of figures 2 and 3 to 

paragraph (g) of this AD into the existing 

AFM. 

(1) For Model 737–8 and 737–9 airplanes: 

Before further flight. 

(2) For all airplanes except Model 737–8 

and 737–9 airplanes: Within 7 days after 

February 18, 2020 (the effective date of AD 

2020–03–20). 

BILLING CODE 4910–13–P 


ddrumheller on DSK120RN23PROD with PROPOSALS1
86076 Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules 

Figure 1 to Paragraph (g)—Affected OPS 

Software 


ddrumheller on DSK120RN23PROD with PROPOSALS1EP12DE23.003</GPH>

Airplanes OPS Software Number 

Model 777-200, 777-200LR, 777-300, COL4D-0087-0002 

777-300ER, and 777F series airplanes 

Model 737-600, 737-700, 737-700C, COL4E-0087-0001 

737-800, 737-900, and 737-900ER series 

airplanes; and Model 73 7-8, and 73 7-9 

airplanes 

All airplanes COL48-0087-0700 

Model MD-11, MD-I IF, and 717-200 COL49-0087-0701 

airplanes; and Model 73 7-600, 73 7-700, 

737-700C, 737-800, 737-900, 737-900ER, 

747-400F, 747-400, 757-200, 757-200PF, 

757-200CB, 757-300, 767-200, 767-300, 

767-300F, 767-400ER, 767-2C, 777-200, 

777-200LR, 777-300, 777-300ER, and 

777F series airplanes 
Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules 86077 

Figure 2 to Paragraph (g)—AFM— 

Limitations or Certificate Limitations 


ddrumheller on DSK120RN23PROD with PROPOSALS1EP12DE23.004</GPH>

Electronics - Global Landing Unit (GLU) (Required by AD 2020-03-20) 

Operations that require less than 0.3 RNP (For example, 0.1, 0.11, 0.15, etc.) in the region 

identified below are prohibited with GLU-2100 OPS software number COL4D-0087-0002, 

COL4E-0087-0001, COL48-0087-0700, or COL49-0087-0701 installed. 

Exception: Anchorage (PANC) approach procedures that allow less than RNP 0.3 are 

authorized provided the instructions outlined in the Electronics - Global Landing Unit 

Section of Normal Procedures Chapter are followed. 

Note: Currently, Fairbanks (PAFA) and Anchorage (PANC) are the only airports in the 

region with an RNP approach that requires better than 0.3 nmi performance. 

Region bounded by the following coordinates: 

Latitude Range (degrees) Longitude Range (degrees) 

80Nto 70N 40 Eto40W 

70Nto 69N 134.5 E to 134.38 W 

69Nto 68 N 134.5 E to 137.28 W 

68 Nto 67N 134.5 E to 139.50 W 

67Nto 66N 134.5 E to 141.58 W 

66Nto 65 N 134.5 E to 144.23 W 

65 Nto 64 N 134.5 E to 145.48 W 

64 Nto 63 N 134.5 E to 146.44 W 

63 Nto 62 N 134.5 E to 148.33 W 

62Nto 61 N 134.5 E to 149.50 W 

61 Nto 60N 134.5 E to 150.35 W 

60Nto 59N 134.5 E to 151.00 W 

59Nto 58 N 134.5 E to 151.40 W 

58 Nto 57N 134.5 E to 152.62 W 

57Nto 56N 134.5 E to 153.42 W 

56Nto 30N 154 Eto 154 W 

30Nto 5 N 163 Eto 163 W 

5Nto10S 166 Eto 166W 

10 S to 15 S 170 Eto 170W 

EP12DE23.005</GPH>ddrumheller on DSK120RN23PROD with PROPOSALS1

j. . ---~ -~ 

_.,.,,+.,··• -+,,,., ...... HJ, 

I 

l· 

.,, .. ,.,f.,.,,.,; 

!ol I :. I I I I I I I I I . ~,,I I 1--1 

120 130 1-40 1,0 1eo fro 110 .110 -1ao .1,0 .1,40 .130 ~12:0 -110 .100 .eo -eo ~ro .«1 ~tm .,:,o 

Lonolude (dEma}-
Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules 86079 

Figure 3 to Paragraph (g)—AFM— 

Procedures or Normal Procedures 

BILLING CODE 4910–13–C 

(h) Software Installation for Certain 

Airplanes 

For airplanes identified in paragraphs 

(h)(1) through (7) of this AD: Within 12 

months after the effective date of this AD, 

install MMR OPS P/N COL4C–0087–0003, or 

later-approved software version, and do a 

software configuration check to confirm that 

P/N COL4C–0087–0003 or later-approved 

software version is installed. Both the 

installation and the check must be done in 

accordance with a method approved by the 

Manager, AIR–520, Continued Operational 

Safety Branch, FAA. Later-approved software 

versions are those Boeing software versions 

that are approved as a replacement for MMR 

OPS P/N COL4C–0087–0003 and are 

approved as part of the type design by the 

FAA or by The Boeing Company 

Organization Designation Authorization 

(ODA). 

(1) Model MD–11 and MD–11F airplanes 

modified by STC ST01895WI. 

(2) Model 717–200 airplanes modified by 

STC ST04416AT. 

(3) Model 737–600, –700, –700C, –800, and 

–900 series airplanes. 

(4) Model 747–400 and 747–400F series 

airplanes modified by STC ST01892WI. 

(5) Model 757–200, –200PF, –200CB, and 

–300 series airplanes modified by STC 

ST04436AT. 

(6) Model 767–200, –300, –300F, –400ER, 

and –2C series airplanes modified by STC 

ST04436AT or ST01883WI. 

(7) Model 777–200, –200LR, and –300 

series airplanes. 

(i) Software Installation for Certain Other 

Airplanes 

For Model 737–8 and –9 airplanes, Model 

737–900ER series airplanes, and Model 777– 

300ER and 777F series airplanes: Within 12 

months after the effective date of this AD, 

except as specified in paragraph (j) of this 

AD, do all applicable actions identified in, 

and in accordance with, the Accomplishment 

Instructions of the applicable requirements 

bulletin identified in paragraphs (i)(1) 

through (3) of this AD. 

(1) For Model 737–8 and –9 airplanes: 

Boeing Alert Requirements Bulletin 737– 

34A3572 RB, dated October 15, 2020. 

Note 1 to paragraph (i)(1): Guidance for 

accomplishing the actions required by 

paragraph (i)(1) of this AD can be found in 

Boeing Alert Service Bulletin 737–34A3572, 

dated October 15, 2020, which is referred to 

in Boeing Alert Requirements Bulletin 737– 

34A3572 RB, dated October 15, 2020. 

(2) For Model 737–900ER series airplanes: 

Boeing Alert Requirements Bulletin 737– 

34A3573 RB, dated August 5, 2020. 

Note 2 to paragraph (i)(2): Guidance for 

accomplishing the actions required by 

paragraph (i)(2) of this AD can be found in 

Boeing Alert Service Bulletin 737–34A3573, 

dated August 5, 2020, which is referred to in 

Boeing Alert Requirements Bulletin 737– 

34A3573 RB, dated August 5, 2020. 

(3) For Model 777–300ER and 777F series 

airplanes: Boeing Alert Requirements 

Bulletin 777–34A0385 RB, Revision 1, dated 

March 8, 2021. 

Note 3 to paragraph (i)(3): Guidance for 

accomplishing the actions required by 

paragraph (i)(3) of this AD can be found in 

Boeing Alert Service Bulletin 777–34A0385, 

Revision 1, dated March 8, 2021, which is 

referred to in Boeing Alert Requirements 

Bulletin 777–34A0385 RB, Revision 1, dated 

March 8, 2021. 

(j) Exceptions to Service Information 

Specifications 

Where the requirements bulletins 

identified in paragraphs (i)(1) through (3) of 

this AD specify installing MMR option 

selection software (OSS) P/N BCG27–U000– 

0730 or BCG48–U000–05W9 and doing the 

associated software configuration check, this 

AD does not require those actions. 

(k) Terminating Action 

After accomplishing the actions required 

by paragraph (h) or (i) of this AD, as 

applicable, you may remove the AFM 

revision required by paragraph (g) of this AD. 

(l) Credit for Previous Actions 

This paragraph provides credit for the 

actions required by paragraph (i)(3) of this 

AD, if the actions were performed before the 

effective date of this AD using Boeing Alert 

Requirements Bulletin 777–34A0385 RB, 

dated August 7, 2020. 

(m) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager, AIR–520, Continued 

Operational Safety 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 (n)(1) of this AD. 

Information may be emailed to: 9-ANMSeattle-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 

ODA that has been authorized by the 

Manager, AIR–520, Continued Operational 

Safety 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. 

(n) Related Information 

(1) For more information about this AD, 

contact Jeffrey W. Palmer, Aviation Safety 

Engineer, FAA, 2200 South 216th St., Des 

Moines, WA 98198; phone: 562–627–5351; 

jeffrey.w.palmer@faa.gov. 


ddrumheller on DSK120RN23PROD with PROPOSALS1EP12DE23.006</GPH>

Electronics- Global Landing Unit (GLU) (Required by AD 2020-03-20) 

To conduct an approach procedure with GLU-2100 OPS software number COL4D-0087-0002, 

COL4E-0087-0001, COL48-0087-0700, or COL49-0087-0701, installed at Anchorage (PANC) 

with less than 0.3 RNP, accomplish the following prior to dispatch in accordance with AC 

90-l0lA: 

Perform a RNP GPS prediction to ensure the predicted availability of GPS Horizontal 

Integrity Limit (HIL) is less than MAX HIL for the planned operation time frame at 

Anchorage (PANC). 

MAX HIL = 1.8 (RNP - 0.0726 nm) for LNAV with NP engaged 

MAX HIL = 1.8 (RNP - 0.0926 nm) for LNAV with F/D 
86080 Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules 

(2) Service information identified in this 

AD that is not incorporated by reference is 

available at the addresses specified in 

paragraphs (o)(3) and (4) of this AD. 

(o) Material Incorporated by Reference 

(1) The Director of the Federal Register 

approved the incorporation by reference of 

the service information listed in this 

paragraph under 5 U.S.C. 552(a) and 1 CFR 

part 51. 

(2) You must use this service information 

as applicable to do the actions required by 

this AD, unless the AD specifies otherwise. 

(i) Boeing Alert Requirements Bulletin 

737–34A3572 RB, dated October 15, 2020. 

(ii) Boeing Alert Requirements Bulletin 

737–34A3573 RB, dated August 5, 2020. 

(iii) Boeing Alert Requirements Bulletin 

777–34A0385 RB, Revision 1, dated March 8, 

2021. 

(3) For service information identified in 

this AD, 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; website 

myboeingfleet.com. 

(4) 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. 

(5) You may view this material at the 

National Archives and Records 

Administration (NARA). For information on 

the availability of this material at NARA, 

visit www.archives.gov/federal-register/cfr/ 

ibr-locations or email fr.inspection@nara.gov. 

Issued on October 4, 2023. 

Victor Wicklund, 

Deputy Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2023–24306 Filed 12–11–23; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2023–2235; Project 

Identifier AD–2023–01009–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 adopt a 

new airworthiness directive (AD) for 

certain The Boeing Company Model 

737–600, –700, –700C, –800, –900, and 

–900ER series airplanes. This proposed 

AD was prompted by two engine fan 

blade-out (FBO) events that resulted in 

the separation of engine inlet cowl and 

fan cowl parts from the airplane 

damaging the fuselage, which caused 

loss of pressurization and subsequent 

emergency descent. The FBO events 

also resulted in cracks in the primary 

exhaust nozzle, potentially resulting in 

the departure of the primary exhaust 

nozzle and damaging a stabilizer or 

striking the fuselage and window. This 

proposed AD would require an 

inspection or maintenance records 

check to determine if the primary 

exhaust nozzle has an affected part 

number and, for affected primary 

exhaust nozzles, an installation of 

bridge brackets onto the primary 

exhaust nozzle, or as an option, an 

installation of a serviceable primary 

exhaust nozzle. This proposed AD 

would also require revising the existing 

maintenance or inspection program, as 

applicable, to incorporate new 

airworthiness limitations. 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 January 26, 

2024. 

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 

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. 

AD Docket: You may examine the AD 

docket at regulations.gov under Docket 

No. FAA–2023–2235; 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. 

Material Incorporated by Reference: 

• For service information identified 

in this NPRM, 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; website 

myboeingfleet.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. It is also available at 

regulations.gov by searching for and 

locating Docket No. FAA–2023–2235. 

FOR FURTHER INFORMATION CONTACT: Luis 

Cortez-Muniz, Aviation Safety Engineer, 

FAA, 2200 South 216th St., Des Moines, 

WA 98198; telephone: 206–231–3958; 

email: luis.a.cortez-muniz@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–2023–2235; Project Identifier AD– 

2023–01009–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 

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 Luis Cortez-Muniz, 

Aviation Safety Engineer, FAA, 2200 

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

telephone: 206–231–3958; email: 

luis.a.cortez-muniz@faa.gov. Any 

commentary that the FAA receives that 


ddrumheller on DSK120RN23PROD with PROPOSALS1