The Lockheed Martin P-791 is an experimental

aerostatic A subfield of fluid statics, aerostatics is the study of gases that are not in motion with respect to the coordinate system in which they are considered. The corresponding study of gases in motion is called aerodynamics. Aerostatics studies densit ...

and aerodynamic

hybrid airship A hybrid airship or plimp is a powered aircraft that obtains some of its lift as a lighter-than-air (LTA) airship and some from aerodynamic lift as a heavier-than-air aerodyne. A ''dynastat'' is a hybrid airship with fixed wings and/or a lifting ...

developed by

Lockheed Martin The Lockheed Martin Corporation is an American aerospace, arms, defense, information security, and technology corporation with worldwide interests. It was formed by the merger of Lockheed Corporation with Martin Marietta in March 1995. It ...

. The first flight of the P-791 took place on 31 January 2006 at the company's flight test facility at

United States Air Force Plant 42 United States Air Force Plant 42 is a classified aircraft manufacturing plant owned by the United States Air Force in the Antelope Valley, about from downtown Los Angeles. It is also used by the National Aeronautics and Space Administration (N ...

in Palmdale, CA.

Description

The P-791 has a tri-hull shape, with disk-shaped cushions on the bottom for landing. As a hybrid airship, part of the weight of the craft and its payload are supported by aerostatic (buoyant) lift and the remainder is supported by

aerodynamic lift A fluid flowing around an object exerts a force on it. Lift is the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the force parallel to the flow direc ...

. The combination of aerodynamic and aerostatic lift is an attempt to benefit from both the high speed of aerodynamic craft and the lifting capacity of aerostatic craft.

History

The P-791 was designed as part of the

U.S. Army's The United States Army (USA) is the land warfare, land military branch, service branch of the United States Armed Forces. It is one of the eight Uniformed services of the United States, U.S. uniformed services, and is designated as the Army o ...

Long Endurance Multi-intelligence Vehicle The Hybrid Air Vehicles Airlander 10, originally developed as the HAV 304, is a hybrid airship designed and built by British manufacturer Hybrid Air Vehicles (HAV). Comprising a helium airship with auxiliary wing and tail surfaces, it flies usi ...

(LEMV) program, but lost the program's competition to

Northrop Grumman Northrop Grumman Corporation is an American multinational aerospace and defense technology company. With 90,000 employees and an annual revenue in excess of $30 billion, it is one of the world's largest weapons manufacturers and military techn ...

HAV-3 Hybrid Air Vehicles (HAV) Limited is a British limited company and a British manufacturer of hybrid airships, though none have been built since the crash of its last demonstrator. These aircraft use both aerodynamics and lighter-than-air (LTA) ...

design. The P-791 was modified to be a civil cargo aircraft under the name SkyTug, with a lift capability of and plans to scale larger. In March 2016, Straightline Aviation signed a

Letter of intent A letter of intent (LOI or LoI, or Letter of Intent) is a document outlining the understanding between two or more parties which they intend to formalize in a contract, legally binding agreement. The concept is similar to a Heads of agreement ( ...

for 12 LMH1 airships, valued at $480 million.

LMH-1

In 2014, Hybrid Enterprises from Atlanta, Georgia entered into an agreement with Lockheed Martin to market and sell the commercial LMH-1 Hybrid Aircraft built by Lockheed, based on the technology demonstrated by the P-791. At the Paris Air Show in June 2015, Lockheed Martin announced that all required FAA certification planning steps were complete, and Hybrid Enterprises was accepting orders. The LMH1 would initially transport 20 tonnes of cargo or 19 passengers, plus 2 crew members, with deliveries beginning in 2018. In September 2016, plans were announced to operate the LMH-1 craft in

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

. In September 2017 it was announced that the first flight of the LMH-1 was being delayed to 2019.

LMZ1M

The

Lockheed Martin LMZ1M Lockheed (originally spelled Loughead) may refer to: Brands and enterprises * Lockheed Corporation, a former American aircraft manufacturer * Lockheed Martin, formed in 1995 by the merger of Lockheed Corporation and Martin Marietta ** Lockheed Mar ...

is the follow on to the P-791 test vehicle.

References

External links

* *
"Picture of the Lockheed Martin P-791 aircraft"
Airliners.net
Video of test flight
snort.com
"US looking to deploy long-endurance hybrid airship over Afghanistan"
September 2009 engadget.com * *

P-791 The Lockheed Martin P-791 is an experimental aerostatic and aerodynamic hybrid airship developed by Lockheed Martin. The first flight of the P-791 took place on 31 January 2006 at the company's flight test facility at United States Air Force Plant ...