Lockheed Martin joined wing/boxwing projects

Lockheed Martin Advanced Mobility Aircraft (AMA)


21st Century Transport

Most of the planes in the United States' strategic mobility fleet are due to retire early in the next century. Already, the C-141B and KC-135, mainstays of the fleet, are 30 to 35 years old, and are experiencing corrosion and fatigue problems. These are the planes that carry troops and equipment into battle, transport peace keeping forces and humanitarian relief and refuel other military aircraft in flight.

What aircraft will fill these roles in decades to come? Right now, Lockheed Martin Aeronautics Company is studying a new family of mid-sized jet transport aircraft called Advanced Mobility Aircraft (AMA). In the past four years, LM Aero engineers have studied more than 40 design concepts, now focusing on a revolutionary "box wing" design, which will enable greater flight range and multiple refueling booms. Although the basic AMA airframe will be a commercially certified aircraft, extensive use of modular components will allow the AMA to evolve to meet the constantly changing missions of the next century.

Click to expand...

Current Status

Lockheed Martin Aeronautics Company Advanced Design engineers have studied more than 40 aircraft concepts since the initiation of the AMA project in 1994. Concepts studied to date include:

• Conventional high wing aircraft
• Blended Wing/Body aircraft
• Box Wing aircraft with two refueling booms

Current effort is focused on the box wing configuration and the operational advantages of a tanker aircraft with two refueling booms. Given that the USAF will not replace its current tankers on a one-for-one basis, planners will face a "boom intensive environment" in future conflicts. A twin boom aircraft can provide the USAF with the same number of available refueling booms, but at half the number of aircraft with the resulting savings in procurement and operational funds.

Beginning on March 7, 1997, LM Aero flew a scale model of a joined wing tanker/transport concept. With 18 test flights completed, the model exhibited excellent flight characteristics, and the tests met and exceeded all objectives.

Design and construction of the 6.5 foot span remote control model was initiated by the LM Aero Advanced Design Department in late 1996 to demonstrate the basic airworthiness and controllability of the joined wing configuration. The model features multiple control surfaces and capability to quickly test alternate control system set-ups.

Planning is under way for a larger proof-of-concept vehicle in the 2000 time frame.

Click to expand...

Conventional Concepts

A conventional high wing military transport configuration, updated to the latest technology, provides a low risk, but highly capable multi-role tanker / transport. This concept can meet all current air refueling requirements while maintaining full capability for strategic airlift. Using a modular design philosophy, a family of next generation transport aircraft can be designed and manufactured to meet both the strategic and in-theater support roles.

The primary mission of the KC-X concept is the strategic tanker mission using a fuselage mounted “flying boom” and multi-point hose/drogue systems. As a strategic airlifter, the concept can deliver over-sized military equipment into bare bases while providing performance comparable to modern commercial airliners.

The modular medium transport concept uses major structural and system components from the KC-X to reduce life cycle cost. The medium transport is designed to deliver over-sized military cargo into bare bases while providing flight performance comparable to commercial transports. The concept is fully airdrop capable and can operate from short, soft soil fields at reduced take-off weights.

Click to expand...

Revolutionary Concepts

The revolutionary box wing concept is the current focus of the advanced concept development work at Lockheed Martin Aeronautics Company under the AMA program. Given that the USAF will not replace its current tankers on a one-for-one basis, planners will face a “boom intensive environment” in future conflicts. A box wing configuration provides the operational advantage of multi-point / multi-boom refueling with a reduced aircraft size and advanced aerodynamics. A twin boom aircraft can provide the USAF with the same number of refueling booms, but at half the number of aircraft. The box wing tanker is also equipped with two drogue refueling systems for interservice and international operations. This allows a single aircraft to refuel two receptacle equipped aircraft, two probe equipped aircraft, or one receptacle and one probe equipped aircraft nearly simultaneously. The box wing tanker still retains a full cargo capability including roll-on/roll-off loading of vehicles, equipment, and ISO containers.

Another revolutionary concept studied at LM Aero is the blended wing-body transport. A configuration where the wing and fuselage are blended together into one structural component is attractive for future tanker/transport aircraft. The blended wing-body configuration provides generous internal volume for fuel and cargo, but with reduced structural weight. The concept can, like the box wing, employ multi-point refueling and by the nature of its basic shape, can be easily modified to meet low observable requirements.

In military use, AMA will be able to perform airlift and tanker missions through the use of integrated modular tanker systems. This will allow the use of one airframe, with the resulting logistics and operational advantages, to fulfill AMC airlift, airdrop, and air refueling missions. In the airlift role, the AMA can carry all the equipment of the Army's light divisions over a 4,000 NM range. The aircraft can airdrop more than 150 paratroops or two 60,000 pound airdrop loads. For tanker missions, the aircraft can exceed the fuel offload of the KC-135R while retaining its basic airlift capability.

The aircraft will also be an effective member of USAF Air Expeditionary Forces (AEFs) by providing strategic lift for deployments, tanker support in theater, and as a multi-mission aircraft for other AEF requirements. Modular airframe and systems design will allow low cost development of derivative vehicles for a variety of missions including reconnaissance and surveillance, electronic combat, rescue, special operations, global attack with future long-range stand-off weapons, and as a 'mother-ship' for advanced UAVs.

Click to expand...

Contracted Studies

Lockheed Martin Aeronautics Company completed two NASA contracts to analyze and evaluate an equal basis comparison of an advanced conventional, box wing and strut braced wing transport. The program objectives were:

• identify key structural and aerodynamic design features, enabling technologies, and technological challenges
• assess the benefits obtained by integration of emerging technologies with structurally innovative "clean sheet" aircraft concepts
• compare these benefits to the benefits obtained from the same technologies applied on conventional transport aircraft.

Lockheed Martin Aeronautics Company/NASA Box Wing Airliner (325 Passenger)

• Applicable To Wide Range of Vehicle Sizes
• 20% Reduction In Gate Space
• Large Box Wing Aircraft (600+ Passengers) Able to Operate Within Existing International Airports
• With No Infrastructure Changes
• Applicable To Civil and Military Roles

Lockheed Martin Aeronautics Company/NASA Strut Braced Wing Airliner

• Increased Structural Efficiency
• Increased Wing Span Reduces Induced Drag
• Reduced Wing Thickness Allows Wing Sweep Reduction Without Drag Penalty

Over current technology aircraft these advanced concepts result in:

• 23-26% Reduction In Direct Operating Costs
• 21-23% Reduction In Acquisition Costs

Lockheed Martin is now embarking on a second phase of contracted studies to further validate the potential benefits of these concepts.

Click to expand...

Super Freighter

In the commercial market, the globalization of trade, involving "Just-In-Time" (JIT) delivery, is one of the main drivers for expanded air cargo services. Most existing air freighters are modified passenger aircraft, usually converted when they reach mid-life. These freighters, due to their cabins designed for passenger use, do not efficiently carry containerized cargo and cannot handle most oversize industrial equipment and vehicles. Also, more than two-thirds of the world air freighter fleet (approximately 900 aircraft) is over 20 years old, with most not meeting current, or projected noise and emissions standards. The retirement of these freighters, combined with the projected doubling of cargo revenue ton miles (RTMs), means that a significant market may emerge in the next decade for a new long range commercial cargo aircraft with enhanced ease of loading for containers and equipment.

LM Aero/NASA
Box Wing
Super Freighter (Civil)

Cargo Availability

• 35,000 ft.³ Cargo Volume
• 350,000 + lb. Cargo Capacity
• 48 M-1 Cargo Containers
• 36 LD-3 Cargo Containers

The Box Wing Super Freighter meets the future demands on long range cargo aircraft and is compatible with existing ground equipment. It can operate from Group 5 airports with a range in excess of 6,000 NM with a 200,000 lb. payload

The Superfreighter has cargo loading on three decks through eight cargo doors. Multiple deck allow "Combi" operation with passengers on the top deck and cargo on the lower decks.

In military service, the Super Freighter will significantly increase logistic support capability for global range military operations and provide high capacity "pipeline" mobility while allowing military transports to focus on combat support. In comparison to the B747-400F, the LM Super Freighter can provide more ton miles per day with fewer aircraft, and greatly reduced fuel costs.

Click to expand...

Global Range Concepts

Global range aircraft will allow for the projection of U.S. military power anywhere in the world without reliance on overseas bases or pre-positioned supplies. Global range also allows aircrew and support personnel to be stationed within the United States and not at costly, vulnerable forward bases. Global range provides the commander with the point-to-point delivery of men and equipment without use of theater assets or reliance on pre-positioned support.

Several global range concepts have been investigated at Lockheed Martin Aeronautics Company including both evolutionary and revolutionary designs. Initial studies focused on four-engine high-wing designs using high aspect ratio wings and aerodynamic optimization to achieve ranges in excess of 10,000 nautical miles. These studies led to twin engine designs that used natural laminar flow wings and advanced propulsion to achieve the global range mission. Global range activities now focus on the revolutionary box wing concept. The box wing achieves the global range mission with a wing span comparable to the C-5.

Click to expand...

Box Wing
The Box Wing tanker/transport concept was developed in the 1990s. Designed as a strategic mobility aircraft, the Box Wing concept offered multipoint refueling for boom and probe-and-drogue tanking. Engineers at the Lockheed Martin facility in Marietta, Georgia, flew a radio controlled scale model of the Box Wing in 1997 to collect data. The model had a 6.5-foot wing span and successful test flights demonstrated the basic airworthiness and controllability of the joined wing configuration.


Posted: 17 June 2014

Click to expand...

This box wing design by Lockheed Martin is made possible by the use of advanced lightweight composite (nonmetallic) materials. A Rolls Royce Liberty Works Ultra Fan Engine uses advanced turbofan technology to maximize efficiency, achieving a bypass ratio (the flow of air around engine compared to through the engine) nearly five times greater than that of current engines.

Click to expand...

AeroFranz said:

it's the obvious location but it wouldn't provide a sufficiently wide track, IMHO.

Click to expand...

TomS said:

Is there anything that would make a reverse tricycle (two front, one back) arrangement viable again? If so, you could put the twin main gear in the wing roots and just one tail gear in the rear fuselage.

Click to expand...

galgot said:

Or maybe an arrangement like on the B-52 ? With small stablilizer lg in the wings ?
On classic configuration airliners , main gears are usualy located at the wing/fuselage box, already very strong part. On this conf , that box is placed more in front, so the main gear (the one taking the main load at landing for example) would need to be placed further back in another reinforced place. That makes more weight . But then, i'm no engineer, they must have thought of that...

Click to expand...

sienar said:

I wonder what the landing gear arrangement on that is.

Click to expand...