STC ST12333LA

United States of America Departmen t of Transportation Federal Aviation Administration Supplemental Type Certificate 

Original Product TypeCertificateNumber:

s eecontinuation sheet  foradditionaldates  By Direction of the Administrator Signature:

Any alteration of thiscertificate is punishable  by a  fine  of not exceeding $1,000, orimprisonment not exceeding 3  years,orboth.Thiscertificate  may betransferred or made  available to  third personsby licensing agreements in accordance with 14 CFR

21.47. Possession  of thisSupplementalType Certificate  (STC) document by personsotherthan  the  STC holderdoesnot constitute rights to the design data  norto alteran  aircraft,  aircraft engine, orpropeller. The STC’ssupporting documentation (drawings, instructions,specifications, flight manualsupplements,etc.)isthe  property of the STC holder. An  STC holderwhoallowsa person to use the STCtoalteran aircraft, aircraft engine, orpropeller must provide  that person with written permission  acceptable to  the FAA. (Ref. 14  CFR21.120).

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ST12333LA Mammoth Freighters LLC 2060 Eagle Parkway Fort Worth, TX 76177 Part 25 the Title 14, Code of Federal Regulations T00001SE The Boeing Company 777-200LR Series

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

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.

(See Continuation Sheet Page 3 of 7 Pages) 11/10/2022 04/07/2026 Manager, West Certification Branch 7 Conversion of a Boeing 777-200LR all-passenger configuration to an all-cargo configuration airplane in accordance with Mammoth Freighters LLC (Mammoth) Master Drawing List (MDL) MF-2101-009, Revision G, dated March 18, 2026, or later FAA approved revision. The modification includes installation of a main deck left side cargo door, a 9g rigid cargo/smoke barrier, (See Continuation Sheet Page 3 of 7 Pages)

United States of America Departmen t of Transportation Federal Aviation Administration Supplemental Type Certificate 

   EffectiveDate:

 : The transfer endorsement below may be used to notify the appropriate FAA Aircraft Certification Office of the transfer of this Supplemental Type Certificate. The FAA will reissue the certificate in the name of the transferee and forward it to him.

(Name and address of transferee):

(Name and address of grantor):

Date o f transfer:

Any alteration of thiscertificate is punishable  by a  fine  of not exceeding $1,000, orimprisonment not exceeding 3  years,orboth.Thiscertificate  may betransferred or made  available to  third personsby licensing agreements in accordance with 14 CFR

21.47. Possession  of thisSupplementalType Certificate  (STC) document by personsotherthan  the  STC holderdoesnot constitute rights to the design data  norto alteran  aircraft,  aircraft engine, orpropeller. The STC’ssupporting documentation (drawings, instructions,specifications, flight manualsupplements,etc.)isthe  property of the STC holder. An  STC holderwhoallowsa person to use the STCtoalteran aircraft, aircraft engine, orpropeller must provide  that person with written permission  acceptable to  the FAA. (Ref. 14  CFR21.120).

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ST12333LA 04/07/2026 7

United States of America Departmen t of Transportation Federal Aviation Administration Supplemental Type Certificate 

 (Continuation Sheet) Number :  EffectiveDate:

  Any alteration of thiscertificate is punishable  by a  fine  of not exceeding $1,000, orimprisonment not exceeding 3  years,orboth.Thiscertificate  may betransferred or made  available to  third personsby licensing agreements in accordance with 14 CFR

21.47. Possession  of thisSupplementalType Certificate  (STC) document by personsotherthan  the  STC holderdoesnot constituterights to the design data  nortoalteran  aircraft,  aircraft engine, orpropeller. The STC’ssupporting documentation (drawings, instructions,specifications, flight manualsupplements,etc.)isthe  property of the STC holder. An  STC holderwhoallowsa person to use the STCtoalteran aircraft, aircraft engine, orpropeller must provide  that person with written permission  acceptable to  the FAA. (Ref. 14  CFR21.120).

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ST12333LA 04/07/2026 Description of Type Design Change (continued):

a main deck Class E cargo compartment that is accessible during flight, and associated systems.

Maintained in accordance with Mammoth’s Instructions for Continued Airworthiness – Maintenance Planning Document Supplement MF-2101-304, Revision 04, dated January 30, 2026, or later FAA approved revision.

Operated in accordance with Mammoth’s Airplane Flight Manual Supplement (AFMS) MF-2101-306, Revision IR, dated March 28, 2026 or later FAA approved revision.

3. Extended Operations (ETOPS): The type-design reliability and performance of this airplaneengine combination has been evaluated under 14 CFR 25.1535 and found suitable for not more than 180 minute extended operations (ETOPS) when the Configuration, Maintenance, and Procedure (CMP) standards contained in Boeing 777 document D044W054 as supplemented by Mammoth CMP Supplement document MF-2101-312 are complied with. The actual maximum approved diversion time for this modified airplane may be less based on its most limiting system time capability. This finding does not constitute operational approval to conduct ETOPS.

4. Use of automatic landing system above 492,000 lbs. (223,167 kg.) is prohibited.

5. An operational limit of 2000 Flight Cycles (FC), 16000 Flight Hours (FH), or 24 months from the date of installation of the STC, whichever occurs first, is imposed until the STC is amended to remove it.

6. Concurrent installations of the following STCs are required with the installation of this STC:

- LiteAir Aviation Products, Inc. STC ST02073SE, for installation of Lightweight Window Plugs.

- B/E Aerospace Inc. – FSI STC ST12282SE, for installation of a Cargo Handling System.

- Mammoth Freighters LLC STC ST11369DS, for the supernumerary area.

Certification Basis:

Based on 14 CFR § 21.115, 21.101 and the FAA policy for significant changes in FAA Order 8110.48A, the certification basis for the Boeing Company, model 777-200LR Series allpassenger configuration to all-cargo configuration is as follows:

1) Airworthiness Standards for Components and Areas Not Affected by the Change: The type certification basis for the Boeing Company, Model 777-200LR Series is shown on TCDS T00001SE.

United States of America Departmen t of Transportation Federal Aviation Administration Supplemental Type Certificate 

 (Continuation Sheet) Number :  EffectiveDate:

  Any alteration of thiscertificate is punishable  by a  fine  of not exceeding $1,000, orimprisonment not exceeding 3  years,orboth.Thiscertificate  may betransferred or made  available to  third personsby licensing agreements in accordance with 14 CFR

21.47. Possession  of thisSupplementalType Certificate  (STC) document by personsotherthan  the  STC holderdoesnot constituterights to the design data  nortoalteran  aircraft,  aircraft engine, orpropeller. The STC’ssupporting documentation (drawings, instructions,specifications, flight manualsupplements,etc.)isthe  property of the STC holder. An  STC holderwhoallowsa person to use the STCtoalteran aircraft, aircraft engine, orpropeller must provide  that person with written permission  acceptable to  the FAA. (Ref. 14  CFR21.120).

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ST12333LA 04/07/2026 Certification Basis (continued):

2) Airworthiness Standards for Components and Areas Affected by the Change: The original certification basis for the Boeing Company, Model 777-200LR shown on TCDS T00001SE plus the following:

2a) 14 CFR Part 25, effective February 1, 1965, including Amendments 25-1 through 25-146:

25.1, 25.3, 25.23, 25.25, 25.27, 25.29, 25.145, 25.147, 25.161, 25.171, 25.173, 25.175, 25.177,

25.181, 25.301, 25.303, 25.305, 25.307*, 25.321, 25.331, 25.333, 25.335, 25.337, 25.341**,

25.343**, 25.349, 25.351, 25.365, 25.367, 25.427, 25.471, 25.473, 25.477, 25.479, 25.481,

25.483, 25.485, 25.489, 25.491, 25.493, 25.495, 25.499, 25.503, 25.507, 25.509, 25.511, 25.561,

25.571, 25.581, 25.601, 25.603, 25.605, 25.607, 25.609, 25.611, 25.613, 25.619, 25.623, 25.625,

25.629, 25.671, 25.681, 25.683, 25.685, 25.689, 25.693, 25.723, 25.729, 25.733, 25.771, 25.773,

25.777, 25.783, 25.785, 25.787, 25.789, 25.791, 25.793, 25.795, 25.801, 25.809, 25.813, 25.831 except (a) and (g), 25.841 except (a), 25.843, 25.851, 25.853, 25.855, 25.856, 25.857, 25.858,

25.863, 25.869, 25.899, 25.903, 25.951, 25.952, 25.993, 25.1165, 25.1301, 25.1302, 25.1307,

25.1309, 25.1310, 25.1316, 25.1317, 25.1321, 25.1322, 25.1351, 25.1353, 25.1355, 25.1357,

25.1360, 25.1363, 25.1381, 25.1419, 25.1423, 25.1431, 25.1435, 25.1438, 25.1439, 25.1441,

25.1443, 25.1445, 25.1447, 25.1453, 25.1455, 25.1457***, 25.1459***, 25.1501, 25.1519,

25.1523, 25.1529, 25.1535, 25.1541, 25.1555, 25.1557, 25.1581, 25.1583, 25.1585, 25.1587,

25.1701, 25.1703, 25.1705, 25.1707, 25.1709, 25.1711, 25.1713, 25.1715, 25.1717, 25.1719,

25.1721, 25.1723, 25.1725, 25.1729, 25.1733, D25.1, F25.1, F25.3, F25.6, G25.1, H25.1, H25.2, H25.3, H25.4, H25.5, K25.1, K25.2, L25.1.

2b) 14 CFR Part 25 Regulations at amendments earlier than the date of application:

25.21 Amendment 25-72, 25.119 Amendment 25-94, 25.121 Amendment 25-84,

25.125 Amendment 25-108, 25.143 Amendment 25-108, 25.307* Amendment 25-72,

25.341** Amendment 25-86, 25.343** Amendment 25-86, 25.345 Amendment 25-91,

25.373 Amendment 25-86, 25.721 Amendment 25-32, 25.731 Amendment 25-72,

25.735 Amendment 25-92, 25.831(a)(g) Amendment 25-25-41, 25.841(a) Amendment 25-38,

25.981 Amendment 25-125, 25.994 Amendment 25-57, 25.1419 Amendment 25-72,

25.1457*** Amendment 25-65, 25.1459*** Amendment 25-65, Appendix G25.1 Amendment 25-54.

* Landing gear at 25-72, all other affected areas at 25-139.

** Unaffected structure analyzed at 25-86, new and affected structure analyzed at 25-141.

*** Line numbers 857 and below at 25-65. Line numbers 858 and on at 25-124.

United States of America Departmen t of Transportation Federal Aviation Administration Supplemental Type Certificate 

 (Continuation Sheet) Number :  EffectiveDate:

  Any alteration of thiscertificate is punishable  by a  fine  of not exceeding $1,000, orimprisonment not exceeding 3  years,orboth.Thiscertificate  may betransferred or made  available to  third personsby licensing agreements in accordance with 14 CFR

21.47. Possession  of thisSupplementalType Certificate  (STC) document by personsotherthan  the  STC holderdoesnot constituterights to the design data  nortoalteran  aircraft,  aircraft engine, orpropeller. The STC’ssupporting documentation (drawings, instructions,specifications, flight manualsupplements,etc.)isthe  property of the STC holder. An  STC holderwhoallowsa person to use the STCtoalteran aircraft, aircraft engine, orpropeller must provide  that person with written permission  acceptable to  the FAA. (Ref. 14  CFR21.120).

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ST12333LA 04/07/2026 Certification Basis (continued):

3) Additional Design Requirements and Conditions:

The following design details or information must be maintained to ensure that an unsafe design condition is not present:

Protection of Critical Systems: Critical systems are those systems needed for the continued safe flight and landing of the airplane following cargo fire detection. In substantiating protection of critical systems, the design must consider:

3.1) Critical systems include, but are not limited to, critical flight control cables, critical wiring and other electrical wiring interconnection system (EWIS) components, windows (if loss of a window could contribute to loss of suppression capability), the flight data recorder, and the cockpit voice recorder.

3.2) Protection of critical systems and the electrical wiring interconnection systems (EWIS) components required for continued safe flight and landing located in, or in close proximity to, the Class E compartment must be accomplished by any one or combination of the following:

a. Routing below the main deck floor and outside of the cargo compartment;

b. Routing behind fire resistant liners that meet the requirements of part 25, appendix F, part III (amendment 25-60);

c. Use of EWIS components that are qualified for the environment in which they are to be installed in accordance with the requirements of § 25.1703. For example, use of wire with adequate temperature rating in locations subjected to potential high temperatures on the backside of cargo liners and above ceiling panels;

d. Routing redundant wiring and associated EWIS components with adequate physical separation as required by § 25.1707. For example, routing redundant wiring and associated EWIS components on opposite sides of the main deck floor and/or opposite sides of the crown area, and ensuring EWIS is adequately protected as required by § 25.1721;

e. Routing redundant control cables to meet separation requirements;

f. Placement of air dams or fire stops behind cargo liners as required to prevent propagation of fire behind the liner;

g. Placement of special fire resistant covers behind air return grilles, decompression vents, and dadoes, as required.

United States of America Departmen t of Transportation Federal Aviation Administration Supplemental Type Certificate 

 (Continuation Sheet) Number :  EffectiveDate:

  Any alteration of thiscertificate is punishable  by a  fine  of not exceeding $1,000, orimprisonment not exceeding 3  years,orboth.Thiscertificate  may betransferred or made  available to  third personsby licensing agreements in accordance with 14 CFR

21.47. Possession  of thisSupplementalType Certificate  (STC) document by personsotherthan  the  STC holderdoesnot constituterights to the design data  nortoalteran  aircraft,  aircraft engine, orpropeller. The STC’ssupporting documentation (drawings, instructions,specifications, flight manualsupplements,etc.)isthe  property of the STC holder. An  STC holderwhoallowsa person to use the STCtoalteran aircraft, aircraft engine, orpropeller must provide  that person with written permission  acceptable to  the FAA. (Ref. 14  CFR21.120).

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ST12333LA 04/07/2026 Certification Basis (continued):

3.3) Substantiate protection of critical systems from the initial growth and potential propagation of the fire, from the residual heat after the airplane has been depressurized, the potential propagation of the fire after the cabin is re-pressurized and during descent, approach through landing and the initiation of emergency evacuation.

3.4) If protective covers are used to protect critical systems, they must be constructed of materials that meet the requirements of part 25, appendix F, part III (amendment 25-60).

4) Exemptions from 14 CFR Part 25: None.

5) Equivalent Safety Findings:

The FAA made the following equivalent level of safety (ELOS) findings for the subject regulations:

14 CFR §25.571(b) Amdt. 25-132 – Freedom from Widespread Structural Fatigue Damage.

Refer to ELOS Memo ST17720LA-T-A-1.

14 CFR §25.855(i) Amdt. 25-142 – Inadvertent Smoke Detection in Forward and Aft Lower Lobe Class C Cargo Compartments from a Smoke Source in a Main Deck Class E Compartment. Refer to ELOS Memo ST17720LA-T-ES-1.

14 CFR §25.773(a)(2) Amdt. 25-144 – Flight Test Requirements for Effects on Pilot Compartment View. Refer to ELOS Memo ST17720LA-T-SE-1.

6) Special Conditions: None.

7) 14 CFR Part 26:

Effective December 10, 2007, including Amendments 26-1 through 26-7. Based on 14 CFR §

21.101(g), applicable provisions of 14 CFR Part 26 are included in the certification basis. For any future 14 CFR Part 26 amendments, the holder of this STC must demonstrate compliance with the applicable sections. As of the issuance date of this STC, compliance has been found for the following regulations:

26.1, 26.5, 26.41, 26.47.

United States of America Departmen t of Transportation Federal Aviation Administration Supplemental Type Certificate 

 (Continuation Sheet) Number :  EffectiveDate:

  Any alteration of thiscertificate is punishable  by a  fine  of not exceeding $1,000, orimprisonment not exceeding 3  years,orboth.Thiscertificate  may betransferred or made  available to  third personsby licensing agreements in accordance with 14 CFR

21.47. Possession  of thisSupplementalType Certificate  (STC) document by personsotherthan  the  STC holderdoesnot constituterights to the design data  nortoalteran  aircraft,  aircraft engine, orpropeller. The STC’ssupporting documentation (drawings, instructions,specifications, flight manualsupplements,etc.)isthe  property of the STC holder. An  STC holderwhoallowsa person to use the STCtoalteran aircraft, aircraft engine, orpropeller must provide  that person with written permission  acceptable to  the FAA. (Ref. 14  CFR21.120).

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ST12333LA 04/07/2026 Certification Basis (continued):

8) Environmental Standards for the Changed Product:

14 CFR Part 34 – Fuel Venting and Exhaust Emission Requirements for Turbine Engine Powered Airplanes: No emissions change in accordance with 14 CFR 21.93(c).

14 CFR Part 36 – Noise Standards: Aircraft Type and Airworthiness Certification14 CFR Part 36, Stage 4 through Amendment 36-31.

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