Zeppelin NT

__NOTOC__ Infobox Aircraft
name=NT


caption=
type=Utility airship
national origin=Germany
manufacturer=Zeppelin Luftschifftechnik
designer=
first flight=September avyear|1997
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retired=
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number built=4
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Zeppelin NT ("N"eue "T"echnologie", German for "new technology") is a class of airships being manufactured since the 1990s by the German company "Zeppelin Luftschifftechnik GmbH" (ZLT) in Friedrichshafen. The company can be considered the successor of the companies founded by Ferdinand von Zeppelin which constructed and operated the very successful Zeppelin airships in the first third of the 20th century. There are, however, a number of notable differences between the Zeppelin NT and the dirigibles of those days, as well as between the Zeppelin NT and usual non-rigid airships known as blimps. The Zeppelin NT is classified as a semi-rigid airship.

Technology

The Zeppelin NT airships constructed so far are 75 m long, with a volume of 8,225 m³.Citation| last=Zeppelin Luftschifftechnik GmbH| year=2008| url=http://www.zeppelin-nt.de/pages/E/luftsch_u_zepp.htm| title=Das Luftschiff] They are thus considerably smaller than the old Zeppelins. Furthermore, they are inflated exclusively with the non-flammable noble gas helium.

In standard operations with a maximum payload, the gas cells do not create enough buoyancy to make the whole ship "lighter-than-air." The negative buoyancy is overcome with engine power. The buoyancy can change when traveling with reduced payload and partially emptied fuel tanks, but usually the Zeppelin NT starts its journey with a net downward force of about 3,000 N (306 kg), and on long trips can end up lighter than air if a lot of fuel is used.

Some have erroneously described the design as a hybrid airship. However that term is most often used only for aircraft that use aerodynamic forces to carry at least 40% of the total aircraft weight. The aircraft is most accurately characterized as an airship that uses vectored thrust to compensate for its static heaviness.Fact|date=December 2007

The Zeppelin NT is a "semi-rigid" airship. It is unlike both the original Zeppelins that had a rigid skeleton and non-rigid blimps. It has an internal triangular truss made of graphite-reinforced plastic and three longitudinal girders made of aluminium which connect the triangular elements along the length of the frame. This frame holds the engines, control car and the steering fins. Additionally, this structure is tightened with aramid cords. It weighs only about 1,000 kg (2,200 pounds).

Hull

Inside the hull of the historical Zeppelins the gas cells were separate entities. However the hull of the Zeppelin NT serves both as the hull and as the gas cell. It is made of a three-layered laminate: one gas-tight layer of Tedlar (PVF), one polyester fabric layer to provide stability and one polyurethane layer suitable for thermic welding that serves to connect the separate laminate panels.

To preserve its outer form, a slight overpressure of about 5 millibar is maintained within the hull. As in blimps, this pressure is kept constant by using ballonets. The ballonets have a total volume of 2,000 m³.

Propulsion and steering

Three propeller engines of the type "Textron Lycoming IO-360" with a power of 147 kW (200 metric hp) each provide the Zeppelin NT with excellent maneuverability. Two lateral engines, equipped with tilting propellers and usually aligned horizontally, can be turned 90° upward or 30° downward. The aft engine powers a pushing propeller that can be turned 90° downward, as well as a "steering propeller" directed to the side and working similarly to the lateral-thrust units of some ships.

Instead of four rudder and elevator fins, the Zeppelin NT uses only three, which saves weight. As a side effect, the loss of one fin can be compensated with the remaining two.

The controls are implemented by fly-by-wire technology, with the pilot using a joystick to steer in three dimensions.

Flying capabilities

The design currently has a range of some 900 km (500 nautical miles) and reaches top speeds of 125 km/h (70 nautical mph or 78 mph). The standard cruising speed of 70 km/h for tourist flights can be attained using the rear propeller only. Standard operational altitude is 300 m (1000 ft), but up to 2,600 m (8,500 ft) is possible. Their maximum permitted takeoff weight is 10,690 kg, with a payload of 1,900 kg.

The Zeppelin NT is able to take-off and land vertically. Only three helpers are required on the ground.

Capacity

The Zeppelin NT has a passenger capacity of 12, plus 2 crew, or the capability to lift 1,900 kg of payload.

Range of application

Since August 15 2001 the "Deutsche Zeppelin-Reederei" (German for "German Zeppelin shipping company") has successfully offered joyrides with Zeppelin NT airships. The hull surfaces are marketed as advertising space. The DZR was founded as a subsidiary of the ZLG in January 2001.

The craft are also used as observation platforms for photographers and television commentators covering major events.

Due to their capability for long low-vibration flight (up to 24 hours), the ZLG also considers the airships well-suited to research missions for environmental observations, troposphere research or prospecting natural resources.

Project history

The modern development and construction was financed from an endowment, initially funded with money left over from the earlier Zeppelin company, that had been under the trusteeship of the Mayor of Friedrichshafen. A stipulation on the endowment limited use of its funds to the field of airships. Over the many years, the investment value of the endowment grew to a point where the time seemed right to use it for the design, development, and construction of a new Zeppelin.

The initial design study was prepared in 1989. The ZLT was founded as a spin-off of the Zeppelin company in September 1993. It began to construct a prototype in 1995. The prototype first took to the air in September 1997.

On July 2 2000, the centennial of the first Zeppelin flight, the prototype "SN 01" was christened "D-LZFN Friedrichshafen." Subsequently, it traveled some 3,600 km in test flights.

In 2001 the company began manufacturing the Zeppelin NT in series and began to exploit the airships commercially. The second ship "SN 02" was christened "D-LZZR Bodensee" on August 10 2001 and started to give joyrides five days later. By the end of that year, it had already transported 3222 passengers, a figure that rose to about 30,000 by November 2003.

During the Oktoberfest of 2002 a Zeppelin NT was used for radio experiments in connection with the European Galileo positioning system project for the German Aerospace Center and the ESA.

The third Zeppelin NT "SN 03" was designated "D-LZZF" and first flew in February 2003.

The "Friedrichshafen" is intended to be used for training pilots, for special flights and for presentations. All further ships will be used commercially or sold. As a tribute to the days of Zeppelin mail, a number of mail-carrying flights are planned.

On March 2 2004 the ZLT sold a Zeppelin NT for the first time; "SN 02" was acquired by the Japanese "Nippon Airship Corporation" and was transferred in June 2004, and was to follow the historical route of the 1929 World Tour of the famous dirigible "LZ127 "Graf Zeppelin". After problems with Russian authorities a special ship for huge parts from the Netherlands was chartered and the Zeppelin was shipped from Italy to Japan by sea.The company intends to use the airship mainly for joyrides and advertising.

Steve Fossett and Paul Stroehle set the current speed record for airships over a distance of one kilometer on Wednesday, October 27, 2004 in Friedrichshafen, Germany with a Zeppelin NT. The new world record was set to 111.8 km/h (69.5 mph or 60.4 knots), an improvement of 19 km/h.

It also announced plans to build a larger, 19 seat aircraft. The ship is expected to start commercial flights in the Autumn of 2008. This larger model is to be called the NT14. The "14" comes from the 14,000 cubic meters of envelope volume.

Starting in late 2005 the prototype Zeppelin NT, "D-LZFN Friedrichshafen", was based in Jwaneng, a diamond mining town in southern Botswana, where it conducted an airborne geophysical survey on behalf of De Beers Prospecting Botswana. The airship was moved from Amsterdam to Cape Town by ship and then flown to Gaborone where a Lockheed Martin full tensor gravity gradiometer was installed. This instrument, owned and operated by Bell Geospace, measures changes in the Earth's gravity field associated with geological density variations. The technology is based on accelerometers and the data quality is sensitive to the turbulence and motion usually associated with fixed wing aircraft installations. The airship, flying slowly at night in relatively cool calm air, provides a very stable and vibrationally quiet platform. The resulting data is capable of revealing the rather faint gravity signals associated with Kimberlite pipes buried under the Kalahari sands. This survey came to an end on 20 September 2007, when D-LZFN was irreparably damaged by a whirlwind while moored at its mast.

In January 2006 the Zeppelin Luftschifftechnik GmbH announced building a fourth Zeppelin NT07. NT07 #4 was optioned by California based Airship Ventures in Spring 2007. [ [http://www.airshipventures.com/pressreleases.html June 25 2007 press release on NT #4 option] ] . The new airship completed its first flight on May 21, 2008. [http://www.airshipventures.com/pr_08_05_21.html] On June 26, 2008, ZLT announced that the FAA issued the type certificate for the Zeppelin NT 07, allowing the airship to fly legally in the United States. The airship is expected to arrive at the Port of Beaumont on or about September 26, 2008. After spending three days tethered at the Southeast Texas Regional Airport, the airship will fly cross-country to its base at Moffett Federal Airfield. [ [http://www.beaumontenterprise.com/news/local/airship_to_make_appearance_in_beaumont_08-12-2008.html] ] [http://www.usatoday.com/travel/flights/2007-06-22-zeppelin-airship_N.htm]

Prior to the trip to the USA, the airship, registered D-LZNT, operated sightseeing and pleasure flights over eastern London and the Thames Estuary from an airfield close to Upminster, in Essex, England, advertising "Stella Artois" beer and the DrinkAware campaign. These flights operated between July and September 2008.

pecifications

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crew=2
capacity=12 passengers
length m=75
length ft=246
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volume m3= 8,255
volume ft3= 290,500
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lift kg= 1,900
lift lb= 4,180

eng1 number=3
eng1 type=Textron Lycoming IO-360
eng1 kw= 150
eng1 hp= 200
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max speed kmh=125
max speed mph=78
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Notes

External links

* [http://www.ezep.de/index.html eZEP.de] — The webportal for Zeppelin mail and airship memorabilia
* [http://www.ezep.de/zsg/zsg.html Zeppelin Study Group] — Research group for airship memorabilia and Zeppelin mail
* [http://www.zeppelin-nt.de/index_e.htm Zeppelin Luftschifftechnik GmbH] -- manufacturers' homepage
* [http://www.zeppelintours.com/htm zeppelintours.com] -- trips to Friedrichshafen and Zeppelin NT airship flights
* [http://www.zeppelinflug.de/pages/E/haupt.htm Deutsche Zeppelin Reederei] -- booking joyrides with Zeppelin NT airships
* [http://www.airshipventures.com Airship Ventures Inc.] -- US company bringing a Zeppelin NT to the USA.