Lockheed Flatbed

"Flatbed"
	US Patent illustration
Role	Military transport
Manufacturer	Lockheed
Status	Design study only

Last updated April 20, 2019

The Lockheed "Flatbed" was a proposed cargo aircraft design from the 1980s that mounted large loads "in the open" on the back of the aircraft, similar to a flatbed truck. The name "flatbed" was unofficial, as a more formal name was never assigned. Although there was a fair amount of public information released about the design in the early 1980s, the design was never picked up by the US Air Force and disappeared by the mid-80s.

A cargo aircraft is a fixed-wing aircraft that is designed or converted for the carriage of cargo rather than passengers. Such aircraft usually do not incorporate passenger amenities and generally feature one or more large doors for loading cargo. Freighters may be operated by civil passenger or cargo airlines, by private individuals or by the armed forces of individual countries.

A flatbed truck is a type of truck which can be either articulated or rigid. As the name suggests, its bodywork is just an entirely flat, level 'bed' with no sides or roof. This allows for quick and easy loading of goods, and consequently they are used to transport heavy loads that are not delicate or vulnerable to rain, and also for abnormal loads that require more space than is available on a closed body.

Design and development

Conventional cargo designs generally "mass out" before they "bulk out", meaning that they often fly mostly empty inside. In this case the aircraft is carrying around a large fuselage for no reason, adding mass and drag and thereby lowering performance. Nevertheless, they need to have oversized cargo bays for the cases where they have to carry bulky loads, rare as these may be. Lockheed's patent states:

Historically, transport airplanes have generally been specifically designed to haul either cargo, passengers, or outsize cargo. ... Military cargo aircraft, such as the C-130 and C-141, are designed to haul cargo and some vehicles –but not outsize cargo such as tanks or bridge launchers. The C-5A can carry all militarily defined outsize cargo and large commercial vehicles. Some later military cargo airplanes can carry some outsize vehicles/equipment, but the price is paid in terms of carrying a large fuselage around for the few times such outsize cargo is actually carried. ... Thus an idea transport airplane is considered to be one which is designed to utilize one common airframe to carry passengers, cargo and outsize equipment.

The Flatbed concept avoided these problems by designing the aircraft primarily for massing out, the most common problem. An airliner-sized fuselage is all that is needed for this role. In the case when the aircraft was called upon to carry an oversized load, the cargo bay would be removed, and the cargo chained directly to the back of the aircraft, in the open. Although performance would be greatly degraded due to drag, this would be more than made up for on all the other flights where a more suitable fuselage size was being used.

An airliner is a type of aircraft for transporting passengers and air cargo. Such aircraft are most often operated by airlines. Although the definition of an airliner can vary from country to country, an airliner is typically defined as an aeroplane intended for carrying multiple passengers or cargo in commercial service. The largest of them are wide-body jets which are called also twin-aisle because they generally have two separate aisles running from the front to the back of the passenger cabin. These are usually used for long-haul flights between airline hubs and major cities. A smaller, more common class of airliners is the narrow-body or single-aisle. These are generally used for short to medium-distance flights with fewer passengers than their wide-body counterparts.

In keeping with the flatbed concept, the aircraft was designed to sit low to the ground. Trucks would drive up to the aircraft and push their loads onto the back. The bed of the aircraft consisted of parallel I-beams as the primary load-carrying structure, with metal sheeting on the top to provide a smooth walking surface. Like most cargo aircraft, rollers could be raised through small holes cut in the bed to allow palletted loads to be rolled on and off without requiring a forklift.

An I-beam, also known as H-beam, w-beam, universal beam (UB), rolled steel joist (RSJ), or double-T, is a beam with an I or H-shaped cross-section. The horizontal elements of the "I" are known as flanges, while the vertical element is termed the "web". I-beams are usually made of structural steel and are used in construction and civil engineering.

A forklift is a powered industrial truck used to lift and move materials over short distances. The forklift was developed in the early 20th century by various companies, including Clark, which made transmissions, and Yale & Towne Manufacturing, which made hoists. Since World War II, the use and development of the forklift truck have greatly expanded worldwide. Forklifts have become an indispensable piece of equipment in manufacturing and warehousing. In 2013, the top 20 manufacturers worldwide posted sales of $30.4 billion, with 944,405 machines sold.

In a conventional cargo aircraft the wing is high-mounted to keep the underslung engines as far from the ground as possible. This avoids foreign object damage (FOD) when operating from dirty runways or dirt airfields. This layout also demands that the fuselage be supported from the top, essentially hanging from the wing's spars. For the Flatbed this would not be appropriate because the loads would be carried on top of the aircraft, not hung under it, so Lockheed moved the wing to the low-mounted position similar to most airliners. In order to avoid FOD, the engines were placed above the wing on pylons, which is aerodynamically similar on a modern symmetrical wing planform.

Foreign object damage damage attributed to a foreign object

In aviation, foreign object debris (FOD) is any article or substance, alien to an aircraft or system, which could potentially cause damage.

Likewise, most cargo aircraft use some version of a T-tail in order to leave the area at the end of the cargo bay "open" so trucks can approach it. This requires the tail to be high-mounted on the fuselage, so, as with the wings, this approach would not work on the Flatbed. Instead a large V-tail was used, extending outward from a point forward of the loading area, placing the rudders well to either side of the bed. In order to allow loading and unloading at the same time, the cockpit area at the nose of the aircraft could be rotated to the right, allowing trucks to approach both ends. The aircraft has a number of design features in common with the Lockheed L-1011, most obviously the crew cabin and cockpit area, and the overall size and layout.

T-tail aircraft empennage configuration in which the horizontal plane is at or near the top of the vertical stabilizer

A T-tail is an empennage configuration in which the tailplane is mounted to the top of the fin. The arrangement looks like the capital letter T, hence the name. The T-tail differs from the standard configuration in which the tailplane is mounted to the fuselage at the base of the fin.

V-tail aircraft tail configuration consisting of two stabilizers mounted at an angle from the fuselage

In aircraft, a V-tail or Vee-tail is an unconventional arrangement of the tail control surfaces that replaces the traditional fin and horizontal surfaces with two surfaces set in a V-shaped configuration when viewed from the front or rear of the aircraft. The aft edge of each twin surface is a hinged control surface which combines the functions of both a rudder and elevators.

The patent application shows it carrying two tanks (looking more like M4 Shermans than anything modern), and they also released concept artwork displaying various truck-like palletted loads mounted in a similar fashion. In these cases a small aerodynamic fairing was placed behind the cockpit area, which is flat at the rear, turning it into a sort of "pod". In most cases cargo would be carried under a cargo fairing that extended from the cockpit all the way to the tail, turning it into a fairly conventional-looking design, if somewhat "skinny" compared to traditional cargo designs like the C-5 Galaxy. Additionally, they proposed a passenger carrying module the same size as the cargo fairing. These modules could be unloaded as a single unit, sliding forward off the bed to a special-purpose truck.

The M4 Sherman, officially Medium Tank, M4, was the most widely used medium tank by the United States and Western Allies in World War II. The M4 Sherman proved to be reliable, relatively cheap to produce, and available in great numbers. Thousands were distributed through the Lend-Lease program to the British Commonwealth and Soviet Union. The tank was named by the British for the American Civil War general William Tecumseh Sherman.

Related Research Articles

Lockheed C-5 Galaxy American heavy military transport aircraft

The Lockheed C-5 Galaxy is a large military transport aircraft originally designed and built by Lockheed, and now maintained and upgraded by its successor, Lockheed Martin. It provides the United States Air Force (USAF) with a heavy intercontinental-range strategic airlift capability, one that can carry outsized and oversized loads, including all air-certifiable cargo. The Galaxy has many similarities to its smaller Lockheed C-141 Starlifter predecessor, and the later Boeing C-17 Globemaster III. The C-5 is among the largest military aircraft in the world.

The Airbus A300-600ST or Beluga, is a version of the standard A300-600 wide-body airliner modified to carry aircraft parts and oversized cargo. It received the official name of Super Transporter early on; however, the name Beluga, a whale it resembles, gained popularity and has since been officially adopted. The Beluga XL, based on the Airbus A330 with similar modifications and dimensions, is being developed by Airbus to replace the type around 2020.

The Lockheed L-2000 was Lockheed Corporation's entry in a government-funded competition to build the United States' first supersonic transport (SST) in the 1960s. The L-2000 lost the contract to the Boeing 2707, but that competing design was ultimately canceled for political, environmental and economic reasons.

The Antonov An-225 Mriya is a strategic airlift cargo aircraft that was designed by the Antonov Design Bureau in the Ukrainian SSR within the Soviet Union during the 1980s. It is powered by six turbofan engines and is the heaviest aircraft ever built, with a maximum takeoff weight of 640 tonnes. It also has the largest wingspan of any aircraft in operational service. The single example built has the Ukrainian civil registration UR-82060. A second airframe with a slightly different configuration was partially built. Its construction was halted in 1994 because of lack of funding and interest, but revived briefly in 2009, bringing it to 60–70% completion. On 30 August 2016, Antonov agreed to complete the second airframe for Aerospace Industry Corporation of China as a prelude to AICC commencing series production.

The Arado Ar 232Tausendfüßler, sometimes also called Tatzelwurm, was a cargo aircraft, designed and built in small numbers by the German firm Arado Flugzeugwerke during World War II. The design introduced, or brought together, almost all of the features now considered to be "standard" in modern cargo transport aircraft designs, including a box-like fuselage slung beneath a high wing; a rear loading ramp ; a high-mounted twin tail for easy access to the hold; and various features for operating from rough fields. Although the Luftwaffe was interested in replacing or supplementing its fleet of outdated Junkers Ju 52/3m transports, it had an abundance of types in production at the time, and did not purchase large numbers of the Ar 232.

The empennage, also known as the tail or tail assembly, is a structure at the rear of an aircraft that provides stability during flight, in a way similar to the feathers on an arrow. The term derives from the French language word empenner which means "to feather an arrow". Most aircraft feature an empennage incorporating vertical and horizontal stabilising surfaces which stabilise the flight dynamics of yaw and pitch, as well as housing control surfaces.

A flatcar (US) is a piece of railroad (US) or railway (non-US) rolling stock that consists of an open, flat deck mounted on a pair of trucks (US) or bogies (UK), one at each end containing four or six wheels. Occasionally, flat cars designed to carry extra heavy or extra large loads are mounted on a pair of bogies under each end. The deck of the car can be wood or steel, and the sides of the deck can include pockets for stakes or tie-down points to secure loads. Flatcars designed for carrying machinery have sliding chain assemblies recessed in the deck.

A twin tail is a specific type of vertical stabilizer arrangement found on the empennage of some aircraft. Two vertical stabilizers—often smaller on their own than a single conventional tail would be—are mounted at the outside of the aircraft's horizontal stabilizer. This arrangement is also known as an H-tail, as it resembles a capital "H" when viewed from rear - these were used on a wide variety of World War II multi-engine designs that saw mass production, especially on the American B-24 Liberator and B-25 Mitchell bombers, the British Avro Lancaster and Handley-Page Halifax heavy bombers, and on the Soviet Union's Petlyakov Pe-2 attack bomber.

An aircraft stabilizer is an aerodynamic surface, typically including one or more movable control surfaces, that provides longitudinal (pitch) and/or directional (yaw) stability and control. A stabilizer can feature a fixed or adjustable structure on which any movable control surfaces are hinged, or it can itself be a fully movable surface such as a stabilator. Depending on the context, "stabilizer" may sometimes describe only the front part of the overall surface.

The Shaanxi Y-8 or Yunshuji-8 aircraft is a medium size medium range transport aircraft produced by Shaanxi Aircraft Corporation in China, based on the Soviet Antonov An-12. It has become one of China's most popular military and civilian transport/cargo aircraft, with many variants produced and exported. Although the An-12 is no longer made in Ukraine, the Chinese Y-8 continues to be upgraded and produced. An estimated 169 Y-8 aircraft had been built by 2010.

The Boeing 747 Dreamlifter, also known as the Boeing 747-400 Large Cargo Freighter (LCF), is a wide-body cargo aircraft. At 65,000 cubic feet the cargo hold was the largest in the world for an aircraft, until the Airbus Beluga XL was released. It can hold three times the volume of a 747-400F freighter. Cargo is placed in the aircraft by the world's longest cargo loader. It is an extensively modified Boeing 747-400 that is used exclusively for transporting Boeing 787 Dreamliner aircraft components to Boeing's assembly plants from suppliers around the world.

Semi-trailer Trailer vehicle without a front axle

A semi-trailer is a trailer without a front axle. In the United States, the term is also used to refer to the combination of a truck and a semi-trailer, a tractor-trailer.

The Ling-Temco-Vought (LTV) XC-142 was a tri-service tiltwing experimental aircraft designed to investigate the operational suitability of vertical/short takeoff and landing (V/STOL) transports. An XC-142A first flew conventionally on 29 September 1964, and on 11 January 1965, it completed its first transitional flight by taking off vertically, changing to forward flight and finally landing vertically. Its service sponsors pulled out of the program one by one, and it eventually ended due to a lack of interest after demonstrating its capabilities successfully.

Ground Support Equipment (GSE) is the support equipment found at an airport, usually on the apron, the servicing area by the terminal. This equipment is used to service the aircraft between flights. As the name suggests, ground support equipment is there to support the operations of aircraft whilst on the ground. The role of this equipment generally involves ground power operations, aircraft mobility, and cargo/passenger loading operations.

In naval architecture and aerospace engineering, the fineness ratio is the ratio of the length of a body to its maximum width. Shapes that are short and wide have a low fineness ratio, those that are long and narrow have high fineness ratios. Aircraft that spend time at supersonic speeds, e.g. the Concorde, generally have high fineness ratios.

An airplane house is a residential home made from a retired or scrapped aircraft. The houses are usually old airliners that once carried passengers, but have now been sent to a scrap yard because of age or because of cuts in the airline's fleet.

The 747 Wing House is a unique residential structure designed from the wings of a decommissioned Boeing 747-100 airplane. Located in the Ventura County portion of the Santa Monica Mountains, northwest of the city of Malibu, California, the house has been widely publicized internationally because of its unique design, its sustainable use of recycled materials, the dramatic transportation of the wings to the building site that was completed by a truck and helicopter, and its creative repurposing of abandoned infrastructure to achieve an architectural work of significance. The project was completed by American architect David Randall Hertz, a fellow of the American Institute of Architects, and his firm, the Studio of Environmental Architecture, in 2011. Working with associate Lucas Goettsche, Hertz assembled a team that was able to realize the project after many years of waiting on government approvals.

The Conroy Virtus was a proposed American large transport aircraft intended to carry the Space Shuttle. Designed, beginning in 1974, by John M. Conroy of the Turbo-Three Corporation, it was to incorporate a pair of Boeing B-52 Stratofortress fuselages to form a new craft using existing parts for cost-savings. While the project was seriously considered, it proved impractically large and NASA chose to develop the Boeing 747-based Shuttle Carrier from surplus commercial aircraft instead.

References

US 4379533,"Transport Airplane",issued April 12, 1983
"Flatbed – A Unique and Versatile Transport Airplane" . SAE. 1980-09-01.

Lockheed Flatbed

Contents

Design and development

Related Research Articles

References

See also