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No. of STCs: 21

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA1552WE	Status: Historical	App Date:	Rev Date: 01/01/1960
Description: Installation of stack assembly exhaust.
TC Nos.: L-3-4
Models: Douglas Aircraft Co. Inc.Army A-26B, Army A-26C
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-1219	Status: Historical	App Date:	Rev Date:
Description: Fuselage pressurization, higher horsepower engines and nose wheel steering modification and autopilot installation.
TC Nos.: L-3-4
Models: Douglas Aircraft Co. Inc.Army A-26B, Army A-26C
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-1219	Status: Historical	App Date:	Rev Date: 01/01/1960
Description: Fuselage pressurization, higher horsepower engines and nose wheel steering modification and autopilot installation.
TC Nos.: L-3-4
Models: Douglas Aircraft Co. Inc.Army A-26B, Army A-26C
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-1470	Status: Historical	App Date:	Rev Date:
Description: Alclad sheet .020 2024-T3.
TC Nos.: 2-548, 785
Models: General Dynamics Corporation28-5ACF, PBY-5A (Army OA-10A)
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-1470	Status: Historical	App Date:	Rev Date: 01/01/1960
Description: Alclad sheet .020 2024-T3.
TC Nos.: 2-548, 785
Models: General Dynamics Corporation28-5ACF, PBY-5A (Army OA-10A)
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-240	Status: Historical	App Date:	Rev Date:
Description: Electric hydraulic pump.
TC Nos.: 2A4
Models: Twin Commander Aircraft Corporation680 Series
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-240	Status: Historical	App Date:	Rev Date: 01/01/1960
Description: Electric hydraulic pump.
TC Nos.: 2A4
Models: Twin Commander Aircraft Corporation680 Series
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-385	Status: Historical	App Date:	Rev Date:
Description: 103-inch plastic and metal nose.
TC Nos.: L-3-4
Models: Douglas Aircraft Co. Inc.Army A-26B, Army A-26C
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-385	Status: Historical	App Date:	Rev Date: 01/01/1960
Description: 103-inch plastic and metal nose.
TC Nos.: L-3-4
Models: Douglas Aircraft Co. Inc.Army A-26B, Army A-26C
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-386	Status: Historical	App Date:	Rev Date: 01/01/1960
Description: Jato installation in nacelles.
TC Nos.: L-3-4
Models: Douglas Aircraft Co. Inc.Army A-26B, Army A-26C
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-386	Status: Historical	App Date:	Rev Date:
Description: Jato installation in nacelles.
TC Nos.: L-3-4
Models: Douglas Aircraft Co. Inc.Army A-26B, Army A-26C
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-470	Status: Historical	App Date:	Rev Date: 01/01/1960
Description: ADF loop.
TC Nos.: A-793
Models: Tracor Flight Systems Inc.240 Series
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-470	Status: Historical	App Date:	Rev Date:
Description: ADF loop.
TC Nos.: A-793
Models: Tracor Flight Systems Inc.240 Series
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-474	Status: Historical	App Date:	Rev Date:
Description: Collins AP101 automatic pilot system.
TC Nos.: L-3-4
Models: Douglas Aircraft Co. Inc.Army A-26B, Army A-26C
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-474	Status: Historical	App Date:	Rev Date: 01/01/1960
Description: Collins AP101 automatic pilot system.
TC Nos.: L-3-4
Models: Douglas Aircraft Co. Inc.Army A-26B, Army A-26C
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-529	Status: Historical	App Date:	Rev Date:
Description: Short engine exhaust stacks and modified nacelle and exhaust shroud on aircraft equipped with Wright R-2600-29 engines.
TC Nos.: 2-576
Models: Douglas Aircraft Co. Inc.Army B-23, Army UC-67
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-529	Status: Historical	App Date:	Rev Date: 01/01/1960
Description: Short engine exhaust stacks and modified nacelle and exhaust shroud on aircraft equipped with Wright R-2600-29 engines.
TC Nos.: 2-576
Models: Douglas Aircraft Co. Inc.Army B-23, Army UC-67
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-606	Status: Historical	App Date:	Rev Date: 01/01/1960
Description: Air conditioner.
TC Nos.: L-3-4
Models: Douglas Aircraft Co. Inc.Army A-26B, Army A-26C
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA4-606	Status: Historical	App Date:	Rev Date:
Description: Air conditioner.
TC Nos.: L-3-4
Models: Douglas Aircraft Co. Inc.Army A-26B, Army A-26C
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA692WE	Status: Historical	App Date:	Rev Date: 01/01/1960
Description: Modification consists of spar reinforcements.
TC Nos.: L-3-4
Models: Douglas Aircraft Co. Inc.Army A-26B, Army A-26C
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200

STC Holder: On Mark Engineering Co 7929 Hayvenhurst, Van Nuys, CA 91408, United States		If you are an STC Holder, Contact us to have your company added here!
STC No.: SA692WE	Status: Historical	App Date:	Rev Date:
Description: Modification consists of spar reinforcements.
TC Nos.: L-3-4
Models: Douglas Aircraft Co. Inc.Army A-26B, Army A-26C
ACO: Los Angeles ACO Branch, Tel: +1 (562) 627-5200