Buoyancy assisted aircraft: a new technology to support a 21st century operational concept--stability and reconstruction.

Since the launching of Operation Enduring Freedom, the Nation has been embarked on a renewed (since Vietnam) concept: securing the populations of failed or failing states and providing new governing bodies the resources to overcome governance barriers and to stimulate the development of their economies. The Army and Marine Corps have published a new doctrinal map for these stability and reconstruction (S & R) operations [Army FM 3-24 and Marine MCWP 3-33.5 Counterinsurgency, Dec 2006]. Inherent in stability operations are offensive and defensive combat as well as humanitarian operations. The doctrine has been embraced in Afghanistan, in Iraq, and in the Horn of Africa operations. It is likely to be the norm for the next several decades.

New operational concepts sometimes require new ways of thinking about how to support them logistically. This article suggests new thinking--a new transport concept enabled by the evolution of technology for airlift--that will enable rapid repositioning of forces and one of the most important S & R logistics tasks, distribution operations, in the harsh environments in which these operations are likely to take place.

Rapid repositioning of forces within the operational area--perhaps a whole country, eg, Afghanistan--provides the necessary operational agility to respond to or preempt insurgent operations in Afghanistan, Iraq, and the Horn of Africa, to respond to humanitarian crises such as the Pakistan earthquake or the southeast Asian tsunami, and to provide security for new nation building projects.

As in any campaign the logistics organizations in the theater must distribute supplies and equipment to their customer organizations to sustain the people and systems that carry out the campaign plan. In S & R operations the supplies include not only the normal military commodities but also the commodities and equipment necessary to the nature of the particular S & R missions in which the units are engaged. Such operations range from combat operations to road and building construction to training and humanitarian assistance.

Both force repositioning and distribution challenges in S & R operations are likely to be greater than in conventional campaigns--such as Phase I of Operation Iraqi Freedom--because the transportation infrastructure is likely to be sparse. Forces are more likely to be faced with the kind of infrastructure found in Afghanistan or the Horn of Africa. S & R sites, as in Afghanistan, may be widely separated with unpaved roads connecting them to major hubs. Because of the underdeveloped economy, airfields will be few and a rail network sparse or nonexistent. Such an infrastructure situation suggests a truck-based distribution system as the principal solution. But the poor condition of the roads and the extended distances between likely hubs and the S & R sites mean slow and painful transit for supplies and equipment.

The primitive road infrastructure also presents a security threat because insurgents are likely to attempt to interdict the roads to delay sustainment and project supplies and equipment. As in Afghanistan, the poor infrastructure, especially the absence of multiple routes to S & R sites, also aids the efforts of corrupt officials to exact "tolls" undermining efforts to improve governance. The limited road network also presents insurgents and criminal elements with opportunities to blackmail commercial carriers and contractors and gain financial resources for the insurgency and/or criminal activities. Such security threats against either US/coalition convoys or commercial carriers demand security assets to protect the convoys as well as critical bridges and other infrastructure.

The principal in-country logistics organization will consider the above characteristics in laying out the distribution process from entry points (air and surface ports of debarkation and any railheads) to S & R sites. It probably will establish distribution centers at the entry points to transfer cargo from intra- or inter-theater lift to in-country transport means. Such a transfer traditionally entails unloading the incoming lift and sorting by customer location, loading and dispatching the in-country transport, and back loading intra- or inter-theater transport with retrograde cargo. The distribution centers also should serve as storage sites for heavily used commodities and equipment, maintaining sufficient stock to hedge against supply chain interruptions. They are the logical locations of component repair centers to support the S & R sites as well as medical facilities, both of which rely on the distribution system.

The in-country logistics organization will make maximum use of the infrastructure it finds and can access. It can bring materials handling equipment; it can build warehouses and other necessary facilities; but it can do little in a short time to improve on the transportation network it finds. The logistics organization in Afghanistan did organize and continues to employ a number of Afghan commercial trucking firms to perform much of the distribution to its customers. Not only does the commercial trucking operation meet distribution needs, but it also contributes to the S & R mission by strengthening the economic performance of the Afghan economy, helping to assure a viable trucking industry, and helping the development of good governance by pinpointing corrupt officials demanding bribes for operating rights. This is a model that should be followed in other environments if conditions permit. But even with that success, the fragile road network described above will limit distribution effectiveness and road movement of units, adding risk to the S & R operations. There will be a need for speed of delivery for both repositioning forces and significant amounts of supplies and equipment that can only be met by air.

While air movement of units and resupply is an option, in the face of limited C-130 capable airfields in the areas where the joint task force could locate many S & R sites, fixed wing airlift cannot pick up much of the unit move and distribution workloads. Airfields can be improved or built, but that construction effort would compete for other construction/reconstruction projects critical to the joint task forces stability and reconstruction mission in improving the viability of the government and the country's economy. Helicopter lift is an alternative, but it is more appropriate for short haul tactical distribution and security operations rather than for the longer legs needed to traverse the 500 mile or greater distances from distribution centers to S & R sites or longer distance moves of land force and special operations force units. However, the vertical take-off and landing capability of an air vehicle that could efficiently move C-130 equivalent cargo loads and people over those extended distances could fill the need.

The remainder of this article will suggest that there is a near-term probable technology solution to deploying such an air vehicle for the in-country cargo and force repositioning operations described above. The idea of an air lifter combining the buoyancy of a lighter-than-air dirigible with an airplane's range has been around for several years. Visionaries had foreseen a large aircraft that could carry 500 tons of payload in a large cargo space intercontinental distances, taking off and landing in its own footprint and requiring neither a ground crew to handle lines to secure the aircraft nor ballast to replace the discharged cargo weight for its return trip.

Until recently the technologies to produce such an aircraft had not been developed. The major challenges have been to manage the buoyancy of the aircraft to accomplish vertical lift and landing, to hold the landed position without the large ground crews required of dirigibles, and to load ballast to replace the off-loaded cargo. Some of the contributing technologies have now been demonstrated on a small scale in a Defense Advanced Research Projects Agency (DARPA) project by Aeros Corporation, a producer of dirigibles for the commercial market. One of the critical technology breakthroughs has been to develop a way to control the density of helium by superheating and cooling to regulate lift off so that vector able turboprops can take over the lateral flight with lift assisted by the buoyancy provided by the helium. At destination, the aircraft buoyancy can be reduced by increasing the density of the helium along with creating ballast through other on-board means, causing the aircraft to settle through a low speed control system into the designated landing area. Management of the buoyancy of the aircraft is the central challenge that has been met in the sub scale tests. DARPA has recently funded a flight demonstration of the buoyancy management system, known as "Control of Static Heaviness," which Aeros will accomplish using one of its commercial airships.

The buoyancy assisted aircraft differs from dirigibles in that it might have a rigid semi-monocoque hull structure fabricated from a lightweight but strong composite glass and carbonfiber material that includes gas cells. Further development can assess whether the weight penalty of a rigid structure may detract from its desired load carrying characteristics. The aircraft also would have an all-weather capability; modern avionics permits storm avoidance. Vulnerability to enemy anti-aircraft fire can be mitigated with self-sealing gas cells, aircraft protection systems, and the relatively quiet engines.

Additional development will focus on scaling up the technology to progressively larger craft. Although the original vision of a 500 ton payload capability may be in the distant future, it appears that a 60 ton payload--equivalent to approximately three C-130 loads--may be feasible within five to eight years. The Aeros Corporation concept for a 60 ton payload aircraft (named the Aeroscraft) would be about 420 feet long, 160 feet wide, and 105 feet high--a large flying warehouse with cargo space estimated at 25,000 square feet. Its mission profile would have vertical take off and landing and a cruising speed of about 100 knots with a range of approximately 4000 miles at an altitude of about 12,000 feet.

Such a mission profile could be utilized by the joint task force not only to reposition combat forces and other units, but also to allow the logistics organization to deliver cargo from distribution centers to S & R sites at the extended distances described earlier--and return without refueling. Transit time, albeit slow in aircraft terms, would shrink from days to hours, eg, an 800 nm sortie in about 7 hours versus several days by truck, depending on the road and threat conditions.

Fuel consumption, because of the benefit of the helium buoyancy management technology, would be a fraction of that of a C-130--an important consideration in the world of increasingly high fuel costs. For example, for a 600 mile mission with a 50 ton cargo load, the buoyancy assisted air-craft is estimated to consume about 15,000 pounds of fuel, but the 3 C-130s required would burn nearly 37,000 pounds.

An additional mission for the aircraft could be as a "connector" between a sea base and land forces ashore. When that idea was examined in a Defense Science Board study several years ago, the vertical take off and landing capability with buoyancy management had not been demonstrated. Landing on a ship requires that capability coupled with a low speed control system. The 60 ton capable buoyancy assisted aircraft could make the sea basing concept a more viable option than previously thought.

This aircraft development could make a significant contribution to both operations and sustainment of stability and reconstruction campaigns in the areas of the world most likely to be the scene of persistent conflict. It can produce the same capability as conventional airlift for 500 to 1000 nm force repositioning and distribution without the need for airfields because of its vertical take off and landing characteristics. The question is, will the Department of Defense invest some R & D funds to allow the development of the technologies that have been demonstrated? The Congress eliminated DARPAs Phase II of the research project, which would have led to flying prototypes, principally because of the lack of DOD support (because at that time, the Phase I results had not been demonstrated.)

Clearly DOD is embarked upon a new strategy--stability and reconstruction--for dealing with the persistent conflict experienced since "9-11." The buoyancy assisted aircraft can be the key airlift technology breakthrough that can enable agile force repositioning and a viable sustainment process in support of that strategy.

By Gen William Tuttle USA (Ret.)