C-X: Next-Gen Cargo Plane for the Joint Force

By Matthew Andrews

Change in the operational environment between now and 2036 requires the Air Force to aggressively develop a vertical and/or short takeoff and landing (V/STOL) tactical airlift platform to ensure operational access for the joint force. The foundation for this thesis emanates from an examination of potential adversaries’ emerging anti-access and area denial (A2/AD) threats, the Chairman of the Joint Chiefs of Staff’s (CJCS) Joint Operational Access Concept (JOAC) publication, and recent advances in V/STOL technology. The global security environment is experiencing multiple trends that will require US military intervention to protect national interests. However, evolving technologies are proliferating around the world that challenge the US military’s ability to project and sustain force into intermediate staging and forward operating bases. Based on the 11 precepts from the CJCS’ JOAC, a V/STOL tactical mobility platform is integral for four of those with a major emphasis on sustainment. United States Transportation Command, through Air Mobility Command (AMC), provides air sustainment to the joint force in combat operations. AMC has yet to either define or publicly declare what requirements are necessary for an airlift platform to replace the C-130 when its life expectancy ends in 2030-2040. Therefore, this article also recommends requirements to the Air Force Chief of Staff for the future experimental cargo plane, or C-X.

Anti-Access and Area-Denial Threats

General Dempsey published the JOAC to “describe in broad terms [his] vision for how joint forces will operate in response to emerging anti-access and area-denial security challenges.” Anti-access threats include Russian S-300/400 and Chinese HQ-9/19 series surface-to-air missiles (SAM) that, when incorporated into advanced integrated air defense systems (IADS), challenge US tanker and fighter ranges. Surface-, sea-, and air-launched cruise missiles can reach over 1,000 miles to target intermediate staging bases (ISB). Adversaries have access to extended-range intelligence, surveillance, and reconnaissance (ISR) systems that enable precise targeting information. Satellites, aircraft, and both land and ship-based radar form these ISR systems.

Area-denial threats also present unique challenges to the joint force. Tactical SAMs designed to maintain localized air superiority, such as the Russian 9K330 Tor system (SA-15) batteries, are becoming widely proliferated. Precision-guided rockets, artillery, munitions, and mortars (G-RAMM) provide surface-to-surface indirect fires reaching up to 120 km as demonstrated by the BM-30 Smerch. One salvo from a BM-30 battery’s 300 mm rockets can decimate a large airfield and parking area.

Joint Operational Access Concept

The JOAC is predicated on solving two problems created by A2/AD capabilities: access and sustainment. General Dempsey provides guidance through 11 precepts and 30 required operational capabilities. However, the central idea is leveraging “cross-domain synergy” through increased integration of all services’ capabilities in every domain. Today, Air Mobility Command has the opportunity to transform the future of tactical airlift by committing to the development of vertical and/or short takeoff and landing (V/STOL) aircraft. The V/STOL capability will directly contribute to the success of four precepts  outlined in the JOAC:

  • Consider a variety of basing options.
  • Seize the initiative by deploying and operating on multiple, independent lines of operations.
  • Maneuver directly against key operational objectives from strategic distance.
  • Maximize surprise through deception, stealth, and ambiguity to complicate enemy targeting.

The common thread throughout the above precepts is basing, logistics, and maneuver of land component forces from outside the joint operations area (JOA). The JOAC emphasizes sustainment as the foundation to achieve future joint force success: “Joint forces will require new sustainment concepts that account for adversary capabilities. These innovations may require new platform designs, more robust information networks, and the ability to more rapidly reach distributed combat forces operating in contested areas.”

Current V/STOL Projects

Until recently, the technology to build a V/STOL aircraft capable of overcoming the historically constant 50% load factor (empty weight to aircraft weight ratio) was not in the realm of possibility. Even the impressive weight reduction efforts incorporated in the design of the    V-22 still resulted in a 50 percent load factor. Based on this historical limitation, a V/STOL aircraft would have to weigh 110,000 pounds to carry a Stryker Combat Vehicle weight of 55,000 pounds, which would out-size a C-130 that weighs 90,000 pounds. However, the European Union (EU) and the Defense Advanced Research Projects Agency (DARPA) both have promising new V/STOL projects that have revolutionary implications for the joint force.

The ESTOLAS (Extremely Short Take Off and Land on Any Surface) combines the features of an airplane, helicopter, airship, and hovercraft to make air travel more efficient and cost-effective. Composite materials filled with foam and honeycomb drastically reduces the weight of the glider (Figure 1: ESTOLAS Project). Helium provides the aerostatic lift to complement the aerodynamic and jet lifting forces to achieve flight. The landing gear is hovercraft-like air-cushioned wheel-skis designed for any natural surface.


Figure 1. ESTOLAS Project

The project seeks to develop three weight classes of hybrid aircraft to carry payloads up to 80 tons with a load factor 1.5 to 2 times higher than today’s airplanes. Another advantage is the aircraft will only need 75-175 meters for takeoff and landing distance depending on the weight category. Furthermore, the glider characteristics maximize fuel efficiency increasing flight ranges to a global scale.

Another V/STOL design is DARPA’s VTOL X-Plane. This prototype improves on the V-22 concept. Twenty-four ducted fans are embedded into the wings and canards providing thrust (Figure 2: DARPA VTOL X-Plane). The project seeks to design an unmanned demonstrator that flies 300-400 knots, raises hover efficiency from 60 to 75%, doubles the lift-to-drag ratio to at least 10, and has a 40% load factor. The current load factor goal does not surpass the historical constant, but “[the X-Plane] has the potential to move the technology needle the farthest and provide some of the greatest spinoff opportunities for other vertical flight and aviation products.”


Figure 2. DARPA VTOL X-Plane Project

AMC’s Vision for the C-X

AMC is currently studying what the future airlift fleet will resemble in the 2030s and 2040s when the life expectancies for the C-5M, C-17, and C-130 are complete. The demand for airlift will likely increase. In 2014, General Odierno asserted that he expected the mobility requirements for the new lighter and leaner Army would increase because the reduction of manpower necessitates greater land component flexibility to meet future needs. The requirements for the next future airlift platform, C-X, have either not been defined or not released publicly. At the 2015 Airlift/Tanker Association, General Everhart’s comments did not make it sound like there is a concrete vision for the C-X.

Though other emerging technologies are more promising for strategic airlift to replace the C-5 and C-17, the future of tactical airlift resides in a V/STOL platform that can haul the Army’s mounted combat vehicles. The Army has been dreaming about this type of organic vertical lift capability for decades, describing this future capability as mounted vertical maneuver (MVM). The MVM concept uses “advanced theater airlift platforms, to maneuver and sustain operationally significant, combat-configured, medium-weight mounted forces to tactical and operational depths for immediate employment against objectives of particular significance.” MVM is described as:

Mounted vertical maneuver is the Army’s concept of a future capability to move mounted, protected forces by air across extended distances, from positions either outside or inside the boundaries of the joint operations area (JOA), to strike directly against critical enemy objectives throughout battlespace. MVM will provide versatile options that will extend the reach and power of future joint force commanders (JFC). It will enable JFCs to respond more effectively to opportunity or uncertainty, to conduct forcible entry, to isolate portions of the battlefield, to exploit success, and to expose the enemy’s entire force to direct attack by mobile ground forces at any point. Further-more, MVM could be one of the key means future JFCs use to accelerate the defeat of the enemy by combining the defeat mechanisms of dislocation and disintegration, as described in both joint and army futures concepts. The operational benefits that this capability affords are so great that the Army thinks MVM should be pursued as a national program.

V/STOL aircraft can enable a range of capabilities addressing several JOAC precepts.

Four Precepts

1. Consider a variety of basing options.

Historically, the US has used ISBs and forward operating bases (FOB) to  build up troops and equipment. In many Geographic Combatant Commands (GCC), the ISBs, FOBs, and some of our ports of embarkation are within striking distance of adversarial A2/AD weapons seeking to destroy US force projection capabilities. The JOAC envisions the joint force maneuvering directly from points of embarkation, relying less on ISBs and FOBs.

In addition to advanced hardening and protection technologies on our points of embarkation, the JOAC recommends disaggregating into many temporary bases in both austere and infrastructural environments to increase our survivability, reduce the adversary’s reward for attack, and significantly decrease their targeting effectiveness. However, a major drawback is the increased logistical requirements.

Though AMC leadership has traditionally spoken of creating a single airlifter that dissolves the division between strategic and tactical lift, the JOAC solidifies the need for a tactical airlift platform to replace the C-130. A C-X embracing the V/STOL principles outlined in the ESTOLAS and DARPA VSTOL X-Plane projects will best meet this need.

2. Seize the initiative by deploying and operating on multiple, independent lines of operations.

Overloading the enemy’s capacity to defend every line of operation (LOO) requires less dependence on “major infrastructure nodes” and increases the ability to operate effectively from austere locations. Furthermore, this precept emphasizes the need for MVM to support land forces employing smaller units more rapidly with increased lethality. An air mechanization capability requires both a V/STOL tactical airlift platform and an increased ability to manage complex operations autonomously. These advances will further enable joint forces to operate on numerous LOOs in all domains to seize the initiative from the enemy through multiple avenues of approach. MVM will hold the adversary hostage to a land attack from nearly any direction.

3. Maneuver directly against key operational objectives from strategic distance.

A V/STOL capable aircraft would drastically increase the deployment speed, offensive capability, and abramssurvivability of the Global Response Force (GRF) through the employment of mounted vehicles from a strategic distance. The GRF is made up of a 5,000-man joint task force including an airborne infantry brigade combat team (BCT), a Stryker infantry company, and a mechanized infantry company. The light infantry paratroopers are the only actual unit of the GRF that is rapidly deployable over strategic distances. However, even the parachute delivery of an airborne BCT requires an improved airfield to accomplish the build-up of combat power necessary to transition from defensive to offensive operations. Following the airdrop, the airborne BCT is dependent upon the equivalent of 60 C-17s to deliver the remaining equipment, people, and supplies. Furthermore, light infantry units are at a major disadvantage against mounted adversaries. The Army will transition to air mechanization over the next quarter century given the implementation of a V/STOL airlift platform capable of moving mounted forces.

Possessing assets capable of rapidly maneuvering the Army from outside the joint operational area (JOA) is especially crucial for the GRF and smaller-sized initial assault forces. Regardless of the organic airlift capacity the future Army possesses, only an Air Force asset should have the operational reach to maneuver the Army from outside the JOA to employ direct action on the enemy. Increased operational reach reduces the need for ISBs and increases operational flexibility and tempo by eliminating the pauses associated with intermediate stops.

4. Maximize surprise through deception, stealth, and ambiguity to complicate enemy targeting.

In the context of the JOAC, stealth and deception cannot be achieved using airlift assets but airlift can create ambiguity. The common thread throughout the previously discussed JOAC precepts is basing, logistics, and rapid movement of lethal land component forces. A future V/STOL aircraft achieves the ability to operate on multiple, self-contained LOOs, which forces the enemy to defend against multiple axes. Moreover, eliminating ISBs and FOBs, and maneuvering from points of embarkation creates enough ambiguity that the enemy is precluded from understanding the joint force’s ultimate objectives.

Proposed C-X Requirements

Now that the threats, V/STOL technology and its implications for Army capabilities, and the JOAC have been addressed, the requirements for the new C-X can be explored. The C-X requires a V/STOL capability because a V/STOL platform provides the “ability to move mounted forces by air…to positions close to objective areas, then that mounted force seize[s] critical objectives without extensive pauses or need for immediate reinforcement.” The future force cannot depend on runways for maneuver or sustainment. A reliance on ISB runways enables the enemy’s ability to anticipate axes of approach, drastically reducing the joint force’s options for disaggregated basing. Therefore, the C-X must be capable of taking off and landing in less than 125 meters on any surface. Furthermore, AMC should consider a VTOL-only modification of the C-X, with a reduced load factor, to enable sustainment from mobile sea-bases.

The C-X must expeditiously deliver mounted cargo over strategic distances. A 5,000 unrefueled nautical mile range is enough to cross any ocean and simultaneously have a combat radius that is 2.5 times the range of most surface-to-surface missiles (SSM). A glider-like design or electric power plant could increase the C-X’s range to anywhere in the globe. However, C-X must be air-refueling capable until capable of global ranges. A reasonable speed for the C-X is in the 350-400 knot range to provide expeditious delivery while defending against threats when employing at very low altitudes.

The C-X must be able to defend against radar, infrared, and optical threats. Though there is no doubt that creating a pocket of localized domain superiority will require an integrated multi-domain joint effort, adversaries will continue to find ways to evade our ISR assets and engage targets of opportunity. Therefore, the C-X must have the awareness to detect radar threats and defend with expendables or electronic jamming. The most likely, widely proliferated, and numerous threats include small arms, optical air defense artillery (ADA), and man-portable air-defense systems (MANPADS). Advanced MANPADS, such as the SA-24 “Grinch”, will continue to increase in lethality. Therefore, the C-X must have a large aircraft infrared countermeasure capability similar to LAIRCM. It will need to provide situational awareness for the pilots to fly low altitude in instrument conditions without reducing delivery capability. The C-X will always need to enter the small arms and optical ADA weapons engagement zones to accomplish the mission. Using the cover of darkness and weather will increase C-X survivability as long as the crew situational awareness systems are appropriately integrated for all intended mission sets.


The Air Force must aggressively develop a V/STOL tactical airlift platform to ensure operational access for the joint force. Multiple trends over the past 25 years are creating a volatile and unpredictable global security environment that will require increased US military activity to protect national interests. Furthermore, the global proliferation of evolving technologies is challenging the US military’s ability to project and sustain the force. These A2/AD technologies require a new strategy that, per the JOAC, is independent of ISBs and FOBs. A robust V/STOL capability is integral to four of the CJCS’ JOAC precepts. The JOAC explicitly calls for “new sustainment concepts that account for adversary capabilities.” It states that the joint force needs innovative designs that can rapidly resupply distributed forces in contested areas. Finally, if the Air Force does not deliver a V/STOL system, the Army will likely develop an organic capability to realize their decades-old MVM concept. An organic Army lift capability of this magnitude would likely re-ignite inter-service feuding like those comparable to the Howze and Disoway Boards of 1962 for resolution.

Major Matthew Andrews is a Senior Navigator and USAF weapons officer with more than 2,400 hours in the C-130E, C-130H/H2/H3, and T-1A. He graduated from Air Command and Staff College last year in 2016 and is currently Air Education and Training Command’s Combat Systems Officer Program Chief.

Disclaimer: The views expressed are those of the author and do not reflect the official policy or position of the Department of Defense or the U.S. Government.


One comment

  1. Great work Nubbins! It would be very efficient if the AF and Navy could develop the same system. We are going to replace our C-2s with V-22s. What you are describing would be a major leap forward and worth the wait. After all, the Navy variant would be operating in the same described environment.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s