Hybrid airship
Encyclopedia
"A hybrid airship is an aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

 that combines characteristics of heavier-than-air (HTA) technology, fixed-wing aircraft
Fixed-wing aircraft
A fixed-wing aircraft is an aircraft capable of flight using wings that generate lift due to the vehicle's forward airspeed. Fixed-wing aircraft are distinct from rotary-wing aircraft in which wings rotate about a fixed mast and ornithopters in which lift is generated by flapping wings.A powered...

 or helicopter
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

, and lighter-than-air (LTA), aerostat
Aerostat
An aerostat is a craft that remains aloft primarily through the use of buoyant lighter than air gases, which impart lift to a vehicle with nearly the same overall density as air. Aerostats include free balloons, airships, and moored balloons...

 technology."[1]Examples include helicopter/airship hybrids intended for heavy lift applications and dynamic lift airships intended for long-range cruising. No production vehicles have been built, but several manned and unmanned prototypes have flown and successfully demonstrated the concept.

The term "hybrid airship" has also been used to describe an airship
Airship
An airship or dirigible is a type of aerostat or "lighter-than-air aircraft" that can be steered and propelled through the air using rudders and propellers or other thrust mechanisms...

 combining elements of different types of airships.

Background

Traditional airships have low operating costs, but are limited in several ways, including low payload/volume ratios and low speeds. Additionally, ground handling of airships has historically presented great difficulty. When a purely LTA ship lands, being nearly neutrally buoyant, it is susceptible to wind buffeting. In even a slight breeze, a truck or many ground crew members are required to secure the ship to a mooring mast
Mooring mast
A mooring mast, or mooring tower, is a structure designed to allow for the docking of an airship outside of an airship hangar or similar structure...

.

Heavier-than-air aircraft, while addressing these difficulties, require the use of power to generate lift, and airplanes also require runway
Runway
According to ICAO a runway is a "defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft." Runways may be a man-made surface or a natural surface .- Orientation and dimensions :Runways are named by a number between 01 and 36, which is generally one tenth...

s, while helicopters need even more power to hover. Hybrid airship designs are intended to fill the middle ground between the low operating cost and low speeds of traditional airships and higher speed, but more expensive heavier-than-air aircraft. In addition, by combining dynamic and buoyant lift, hybrids may be able to provide otherwise unattainable air-cargo payload capacity and/or a hovering capability. Such a design is intended to be the "best of both worlds" combination: the high speed of aerodynamic craft and the lifting capacity of aerostatic aircraft. However, critics of the hybrid approach have labeled it as being the "worst of both worlds" declaring that such craft require a runway for take-off and landing, are difficult to control and protect on the ground, and have relatively poor aerodynamic performance.

Most modern airships, for instance the Zeppelin NT or Skyship 600, use some combination of vectored thrust and buoyancy
Buoyancy
In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...

. However, for these designs, almost all of the load is carried via buoyancy, and vectored thrust is used primarily for maneuvering. To date, there is no formal distinction between hybrid airships and airships with vectored thrust.

Concept

The idea behind the hybrid airship is to combine lift from a lighter-than-air gas such as helium with lift from aerodynamic forces. Such a craft is still heavier than air, which makes it similar in some ways to a regular aircraft. The rest of the lift is comes from vertical thrusters such as helicopter-like rotors, or a lift-producing shape (like a wing) combined with horizontal thrust, or a combination of the two. The aerodynamic approach is very similar to that of a conventional lifting body aircraft. The hybrid aircraft technology has a wide range of flight performance behaviors ranging from heavier than air to near buoyant characterizations. This uncommon dynamic flight range when coupled with an air cushion landing system has reinvigorated the LTA community and those seeking ultra heavy and affordable airlift transportation options.

History

No hybrid aircraft design has ever been developed past the initial experimental stages despite many such designs having been proposed over the years, though recent advances may indicate that the technology has matured.

The idea of a tri-lobe airship belongs to Solomon Andrews when he first flew the Aereon back in 1863.[6] The ship he hoped to use for military and commercial was a triple-hulled, gravity powered airship.[6] When the war was over though it took away the need to fund for a controllable reconnaissance airship
vehicle.[6] "Undaunted, Andrews built a single hull airship that moved sideways. To explain how the craft flew, he published a booklet subtitled "Without Eccentricity, There Is No Progression."."[6]

In 1905, Alberto Santos-Dumont
Alberto Santos-Dumont
Alberto Santos-Dumont , was a Brazilian early pioneer of aviation. The heir of a wealthy family of coffee producers, Santos Dumont dedicated himself to science studies in Paris, France, where he spent most of his adult life....

 made what is likely the first attempt at a hybrid aircraft. His Number 14 combined an airship envelope with an airplane frame. At that time, Santos-Dumont was the world's most accomplished aviator. All of his previous flights had been made in purely aerostatically lifted airships. The Number 14 proved unworkable. Later, Santos-Dumont would remove the envelope and successfully use the recristened 14-bis (meaning "14-again
BIS
Bis is a prefix or suffix designating the second instance of a thing, thus preceding ter.Bis can also refer to:* Bis , a Scottish pop band* Bis , a high-teens' magazine published by Kobunsha of Japan...

") to make the first public flight of any heavier-than-air aircraft in the world.

In the timespan of 1923 to 1935 the US Navy operated a four rigid airships, Shenandoah, Los Angeles, Akron, and the Macon. "The loss of three of them to accidents—only Los Angeles retired without mishap—coupled with the loss of the Hindenburg several years later, sounded the death knell for large airship operations."."[3]

The 1986 Piasecki PA-97 Helistat
Piasecki PA-97
- External links :* * - All The World's Rotorcraft*...

 combined four helicopters with a blimp in an attempt to create a heavy-lift vehicle for forestry work.

The Aereon 26
AEREON 26
The AEREON 26 was an experimental aircraft developed to investigate lifting body design with a view to using its shape to create hybrid designs, part airship, part conventional aircraft...

 was an aircraft which made his first flight in 1971. It was was a small-scale prototype of the hybrid Airship Aereon Dynairship and part of the projekt "TIGER". But is was never build because of an unready market for a hybrid airship.

The SkyCat
SkyCat
SkyCat is a class of proposed heavy-lift and ultra-heavy-lift hybrid aircraft which derive more than half of their lift by helium buoyancy and the balance via aerodynamic lift produced by aerodynamic shaping. Such vehicles are not "payload specific"...

 or "Sky Catamaran" vehicular technology is a hybrid aircraft amalgamation; a scale version at 12 meters called "SkyKitten", built by the Advanced Technologies Group Ltd, flew in 2000.

The U.S. Defense Advanced Research Projects Agency, DARPA, initiated the WALRUS
Walrus HULA
The Walrus HULA was a proposed Hybrid Ultra Large Aircraft. The goal was to create an airship capable of traveling up to 12,000 nautical miles in range, while carrying 500-1000 tons of cargo...

 program in 2005, a technology development initiative focused on ultra heavy air lift technology explorations. The program was terminated in 2007.

In 2006, Lockheed Martin's P-791
P-791
The Lockheed Martin P-791 is an experimental aerostatic/aerodynamic hybrid airship developed by Lockheed Martin corporation. The first flight of the P-791 was on 31 January 2006 at the company's flight test facility on the Palmdale Air Force Plant 42. It has a unique tri-hull shape, with...

 manned flight test of the SkyCat technology indicated substantial progress of the technology, and presently several development efforts are underway, although the only program to provide serious funding is the US Army LEMV one awarded last year to Northrop Grumman and Hybrid Air Vehicles.

Current and proposed designs

The Millennium Airship Corporation has Patented their ITAMMS thrust management system and are currently developing a heavy hybrid lift system.

Hybrid Air Vehicles
Hybrid Air Vehicles
Hybrid Air Vehicles Ltd., led by Chief Executive Gary Elliott , is a designer of air vehicles known as hybrid airships. These vehicles, such as the prototype HAV-3, utilize both aerodynamics and lighter-than-air technology to generate lift, potentially allowing the vehicle to stay aloft for a few...

 has the first of three HAV 304's under final construction in the USA. First flight is scheduled for later this year as part of the 517 million dollar US Army LEMV program. Surveillance, remote control and ground station equipment will be supplied by HAV's partner Northrop Grumman. In addition Hybrid Air Vehicles has signed a provisional contract with Canada's Discovery Air to build up to 45 HAV's for oil, gas and mining operations in Northern Canada
Northern Canada
Northern Canada, colloquially the North, is the vast northernmost region of Canada variously defined by geography and politics. Politically, the term refers to the three territories of Canada: Yukon, Northwest Territories, and Nunavut...

. The contract, which the companies hope to have finalised by 2012, is potently worth $3.3 billion with each airship costing $40 million and the first delivery expected in 2014.

"In 2008, Boeing announced it was teaming up with SkyHook to develop a heavy duty lifting vehicle. Part blimp, part helicopter, the SkyHook JHL-40 aircraft is capable of transporting a 40-ton sling load up to 200 miles."[2][4]

An Australian based company is working on a project to develop an air crane called the SkyLifter a "vertical pick-up and delivery aircraft" being capable of lifting up to 150 tons.[2]

"Northrop Grumman has been awarded a US$517 million contract to develop the massive airship and present it for military assessment in just 18 months. The company is developing the LEMV to plug straight into the the Army's existing ground command centers and will provide flight and ground control operations. According to the company release, the LEMV will "operate within national and international airspace" from "austere operating locations using beyond-line-of-sight command and control."[5]

"For heavier payloads, hydrogen-fuelled high-altitude UAVs are a possibility. AeroVironment is close to flying its Global Observer, which is designed to carry a 400-lb. payload to 60,000 ft. for seven days. Boeing plans to fly its Phantom Eye demonstrator in January 2011, with the goal of staying aloft for up to 100 hr. to demonstrate technology for a hydrogen-fueled UAV that would operate for 10 days with a 1,000-lb. payload, and seven days with 2,000 lb."[7]

A Canadian start-up, Solar Ship Inc, is developing solar powered hybrid airships that can run on solar power alone. The idea is to create a viable platform that can travel anywhere in the world delivering cold medical supplies and other necessitates to locations in Africa and Northern Canada without needing any kind of fuel or infrastructure. The hope is that technology developments in solar cells and the large surface area provided by the hybrid airship are enough to make a practical solar powered aircraft. Some key features of the Solarship are that it can fly on aerodynamic lift alone without any lifting gas, and the solar cells along with the large volume of the envelope allow the hybrid airship to be reconfigured into a mobile shelter that can recharge batteries and other equipment.

Treatment in fiction

H.G. Wells' novel Tono-Bungay
Tono-Bungay
Tono-Bungay , by H. G. Wells, is a realist semi-autobiographical novel. It is narrated by George Ponderevo, a science student who is drafted in to help with the promotion of Tono-Bungay, a harmful stimulant disguised as a miraculous cure-all, the creation of his ambitious uncle Edward...

 features the protagonists working on hybrid airship designs with arguable lack of success.

Most of the airships in Castle in the Sky
Castle in the Sky
All compositions by Joe Hisaishi.#"The Girl Who Fell from the Sky" – 2:27#"Morning in Slag Ravine" – 3:04#"A Fun Brawl " – 4:27#"Memories of Gondoa" – 2:46#"Discouraged Pazu" – 1:46#"Robot Soldier " – 2:34...

 are hybrids.

See also

  • Thermoplan
    Thermoplan
    The thermoplan is a disc-shaped airship of hybrid type, currently under development in Russia. The key feature of thermoplan is its two section structure. The main section of the airship is filled with helium, while the other section is filled with air that can be heated or cooled by the engines...

  • Walrus HULA
    Walrus HULA
    The Walrus HULA was a proposed Hybrid Ultra Large Aircraft. The goal was to create an airship capable of traveling up to 12,000 nautical miles in range, while carrying 500-1000 tons of cargo...

  • Aeroscraft
    Aeroscraft
    The Aeroscraft model ML866 is a planned 60-ton hybrid airship, to be built by the Worldwide Aeros Corporation.A scaled-down prototype was made in 2008. A 2006 article in POPSCI reported Worldwide Aeros Corporation was developing a prototype to be completed by 2010. It uses technology from the...

  • Metaplane
  • Piasecki PA-97
    Piasecki PA-97
    - External links :* * - All The World's Rotorcraft*...

  • Skycat
    SkyCat
    SkyCat is a class of proposed heavy-lift and ultra-heavy-lift hybrid aircraft which derive more than half of their lift by helium buoyancy and the balance via aerodynamic lift produced by aerodynamic shaping. Such vehicles are not "payload specific"...


External links

New hybrid airships prepare to take flight - CNN.com
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