VX Aerospace applied its composite engineering and manufacturing capabilities to the Marine Corp’s CH-46E Sea Knight helicopter, designing, prototyping, and producing mor than six dozen unique composite components and assemblies for the aircraft.
May of these components replaced aluminum parts, reducing weight, eliminating corrosion susceptibility and decreasing maintenance man hours.
VX Aerospace’s work on the CH-46E also achieved an important milestone: VX became the first composite manufacturer to qualify and field out-of-autoclave (OOA) cured composite structure on an active duty Navy aircraft.
The CH-46E Sea Knight known more commonly as “The Frog” was a tandem-rotor aircraft that entered service in 1964 and was out of production by 1971. The aircraft was a mainstay vertical lift platform for the Marine Corp until 2015.
PMA-226, the program office for the Frog hired VX to help them extend the life of the H-46 until the V-22 was fully fielded across the Marine Corps. This effort required innovative solutions and short timelines as there were no longer any supply chain sustainment options.
Performing in days and weeks rather than months and years, VX helped the program office support the legacy platform with innovative reverse engineered solutions. Many of these remedies involved replacing aluminum with carbon/epoxy composite materials.
Composite Engineering & Manufacturing
Hundreds of composite components and assemblies were delivered and installed on the CH-46 Sea Knight.
Designing for a legacy aircraft that has been out of production for over four decades has its challenges. There were no CAD models, available tech data was limited and there was significant variation from one aircraft to another. The Marine Corp did provide VX with an airframe. All manor of reverse engineering was applied to accomplish the various design goals.
Shape and loft information was obtained via white light scanning or simply on-aircraft mold making most commonly known as a ‘splash.’ The best approach was, “Whatever it takes.”
Composite Heater Duct Molds
Composite Heater Ducts
Installed Heater Ducts
Out-of-Autoclave Composite Manufacturing
Aerospace grade composites typically have high fiber volume fractions and low void content. To achieve these properties, pressurized ovens called autoclaves have historically been used for processing prepreg composites. The elevated temperature accelerates the resin cure and the increased pressure, commonly around 100 psi, helps to consolidate the laminate in the mold and minimize voids.
Autoclaves, especially large ones, are very expensive to purchase and operate. As aerospace composite systems matured, prepreg laminates were developed that achieved the required properties in fiber volume fraction and void content that could be cured in ambient pressure ovens. VX lead the way in qualifying these material for use on the CH-46 becoming the first company to field out-of-autoclave advanced composite parts on an active Department of the Navy aircraft program.
Program Scope
VX Aerospace’s work on the CH-46E ultimately extended well beyond a single composite component.
Across the program, VX Aerospace:
Together, these accomplishments demonstrate the breadth of VX Aerospace’s composite engineering and manufacturing work on the CH-46E Sea Knight.
Representative Composite Components
Sync Shaft Cover
Nose Bay Door
Production of Ramp Floor Boards
Customer Satisfaction
VX Aerospace’s work received strong feedback from The Adversary and Specialized Aircraft Program Office (PMA-226), highlighting the company’s engineering and production capabilities as well as its responsiveness to Marine Corps requirements:
“VX Aerospace is a very responsive company with a wide range of engineering and production capabilities. They have proven to be very responsive to Marine Corps needs, their products offer tremendous value and their cost and schedule performance is unmatched.” – PMA-226
The assessment highlights the combination of engineering, production, responsiveness, value, and cost and schedule performance VX Aerospace brought to its work supporting Marine Corps aviation.
The CH-46E program demonstrated VX Aerospace’s ability to apply advanced composite engineering and manufacturing to an active military aircraft.
Through the design, prototyping, and production of more than six dozen unique composite components, VX Aerospace demonstrated its ability to replace numerous aluminum parts with composite alternatives while establishing a significant milestone for out-of-autoclave composite manufacturing on an active NAVAIR aircraft.
The program remains an example of VX Aerospace’s experience bringing composite technology from design and prototype development through production and operational use.