STC ST04556CH

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ST04556CH Citadel Completions, LLC 3900 Chennault Parkway Lake Charles, LA 70615 Part 25 the Federal Aviation Regulations A16WE The Boeing Company 737-600 Series, 737-700 Series, 737-800 Series, 737-900 Series, 737-900ER Series Installation of a Crew Oxygen Shutoff Valve in accordance with Citadel Completions, LLC. Master Data List 7097-MDL-002, Revision (E), dated 27 JAN 2022, or later FAA Approved Revision.

1. The installer must determine whether this design change is compatible with previously approved modifications.

(See Continuation Sheet) December 21, 2021 February 10, 2022 January 28, 2022 Manager, Airframe & Administrative Services Section Chicago ACO Branch 4

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Too (Name and address of transferee):

Date oI transfer:

ST04556CH 4

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$Q\ ST04556CH Date reissued: February 10, 2022 Description of Type Design Change - cont.

FAA Approved Aircraft Flight Manual Supplement document number 7097-AFMS-002 Revision (A), dated 14 JAN 2022, or later FAA approved revision is a required part of this modification.

The aircraft must be maintained in accordance with FAA accepted Instructions for Continued Airworthiness, 7097-ICAS-002 Revision (IR) dated 11 JAN 2022, or later FAA accepted revision in addition to the basic airplane maintenance manuals.

Limitations and Conditions - cont.

2. If the holder agrees to permit another person to use this certificate to alter a product, the holder must give the other person written evidence of that permission.

Certification Basis - cont.

Based on 14 CFR §§ 21.101, 21.115 and the FAA policy for significant changes in FAA Order 8110.48A, the certification basis for The Boeing Company 737-600 Series, 737-700 Series, 737-800 Series, 737-900 Series and 737-900ER Series Installation of a Crew Oxygen Shutoff Valve is as follows:

a. The type certification basis for The Boeing Company 737-600 Series, 737-700 Series, 737-800 Series, 737-900 Series and 737-900ER Series is shown on TCDS A16WE for parts not changed or not affected by the change.

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b. The certification basis for parts changed or affected by the change since the reference date of application, 21 DEC 2021, is based upon TCDS A16WE. Based on 14 CFR § 21.101, 21.115 and the FAA policy for significant changes in FAA Order 8110.48A, the certification basis for this modification was determined to be:

Regulations at the amendment level in TCDS A16WE:

25.1(a,b)[Original], 25.23(a)[Original], 25.301(a,b)[25-23], 25.303[25-23], 25.305(a,b) [25-86], 25.307(a)[25-72], 25.601[Original], 25.603(a-c)[25-46], 25.605(a)[25-46],

25.609(a,b)[Original], 25.611[25-23], 25.613(a,b,d)[25-72], 25.619(a-c)[25-23], 25.625

(a)[25-72], 25.869(a(4),c)[25-72], 25.1301(a-d)[Original], 25.1307(c)[25-72], 25.1322 (a,c)[25-38], 25.1351(a(1))[25-72], 25.1353(a,b)[25-42], 25.1357(a,c)[Original], 25.1431 (a,c)[Original], 25.1438(a-c)[25-41], 25.1441(a-c)[Original], 25.1443(b)[Original],

25.1449[Original], 25.1453(a,b)[Original], 25.1519[Original], 25.1529[25-54], 25.1581 (a,b,d)[25-72], 25.1583(a-i)[25-72], 25.1585(a-e)[25-46],

25.1587(a,b)[25-72].

Regulations at higher amendment level:

25.853(a)[25-116], 25.1309(a,b,d,g)[25-41].

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