The Lockheed Martin X-55 Advanced Composite Cargo Aircraft (ACCA) is an experimental
twinjet
A twinjet or twin-engine jet is a jet aircraft powered by two engines. A twinjet is able to fly well enough to land with a single working engine, making it safer than a single-engine aircraft in the event of failure of an engine. Fuel efficien ...
transport aircraft Transport aircraft is a broad category of aircraft that includes:
* Airliners, aircraft, usually large and most often operated by airlines, intended for carrying multiple passengers or cargo in commercial service
* Cargo aircraft or freighters, fix ...
. It is intended to demonstrate new
air cargo-carrier capabilities using advanced
composite material
A composite material (also called a composition material or shortened to composite, which is the common name) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or ...
s. A project of the
United States Air Force
The United States Air Force (USAF) is the Aerial warfare, air military branch, service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part ...
's
Air Force Research Laboratory
The Air Force Research Laboratory (AFRL) is a scientific research organization operated by the United States Air Force Materiel Command dedicated to leading the discovery, development, and integration of aerospace warfighting technologies, pl ...
, it was built by the international aerospace company
Lockheed Martin, at its Advanced Development Programs (''
Skunk Works
Skunk Works is an official pseudonym for Lockheed Martin's Advanced Development Programs (ADP), formerly called Lockheed Advanced Development Projects. It is responsible for a number of aircraft designs, beginning with the P-38 Lightning in 1 ...
'') facility in
Palmdale, California.
Design and development
The X-55 is a one-off aircraft intended to demonstrate the use of advanced composite materials in the fuselage of an otherwise conventional
high-wing
A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes.
A monoplane has inherently the highest efficiency and lowest drag of any wing co ...
transport aircraft. There are no plans to place the X-55 into production.
Lockheed Martin's design for Advanced Composite Cargo Aircraft (ACCA) was chosen over
Aurora Flight Sciences
Aurora Flight Sciences is an American aviation and aeronautics research subsidiary of Boeing which primarily specializes in the design and construction of special-purpose Unmanned aerial vehicles. Aurora has been established for 20+ years and th ...
' design based on the
Antonov An-72
The Antonov An-72 (NATO reporting name: Coaler) is a Soviet/Ukrainian transport aircraft, developed by Antonov. It was designed as an STOL transport and intended as a replacement for the Antonov An-26, but variants have found success as comme ...
in 2007. The aircraft is powered by two
Pratt & Whitney Canada PW306B turbofan
The turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft propulsion. The word "turbofan" is a portmanteau of "turbine" and "fan": the ''turbo'' portion refers to a gas turbine engine which achieves mechanic ...
s.
The X-55 design is based on the existing
Fairchild Dornier 328JET
The Fairchild-Dornier 328JET is a commuter airliner, based upon the turboprop-powered Dornier 328, developed by the German aircraft manufacturer Dornier Luftfahrt GmbH. It would be the last Dornier-designed aircraft to reach production before ...
. The fuselage of that aircraft, which is constructed of
aluminium alloy
An aluminium alloy (or aluminum alloy; see spelling differences) is an alloy in which aluminium (Al) is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon, tin, nickel and zinc. There are two principa ...
s, was replaced aft of the entrance door with a newly designed fuselage. The new design makes extensive use of advanced composite materials, selected to allow out-of-
autoclave (industrial)
An autoclave is a machine used to carry out industrial and scientific processes requiring elevated temperature and pressure in relation to ambient pressure and/or temperature. Autoclaves are used before surgical procedures to perform sterilizati ...
curing at lower temperatures and pressures than previous materials. The new widened fuselage allows the loading of cargo through a rear ramp.
The new fuselage section is constructed as a single large component, including the
vertical stabilizer
A vertical stabilizer or tail fin is the static part of the vertical tail of an aircraft. The term is commonly applied to the assembly of both this fixed surface and one or more movable rudders hinged to it. Their role is to provide control, s ...
. When attached to the existing nose section, the fuselage is 55 feet (16.8 m) long and 9 feet (2.74 m) diameter. The fuselage has upper and lower halves, each with a roughly-oval shape similar to a canoe. The halves are bonded to circular frames. The fuselage section ahead of the entrance door consists of the existing (metal) 328J component, with fasteners used to bring the forward and new aft sections together.
As of April 2008, the fuselage was being fabricated. The first flight of the modified aircraft was expected during the winter of 2008/2009. However, due to a "glitch" during fabricating the composite fuselage, that schedule slipped. The delay was caused by an unsatisfactory bond of the skin on the lower fuselage, which required a second fuselage to be fabricated.
The first flight was completed at Lockheed Martin's Advanced Development Programs facility (Air Force Plant 42) in Palmdale, California on June 2, 2009 by the Air Force Research Laboratory in conjunction with Lockheed Martin. In October 2009, the ACCA demonstrator was designated ''X-55A'' by the USAF. Over the course of the program, 15 to 20 flights were expected. Furthermore, it was estimated that the vehicle was built for half the cost of a conventional design for a similar aircraft.
Aircraft on display
File:Lockheed-Martin X-55A ‘N807LM’ (27020876124).jpg, X-55 ''(N807LM)'' on display at Joe Davies Heritage Airpark
File:Lockheed-Martin X-55A ‘N807LM’ (27631301015).jpg, A different view of the aircraft
As of September 12, 2014, the X-55 aircraft is on display at
Joe Davies Heritage Airpark
The Joe Davies Heritage Airpark at Palmdale Plant 42, formerly known as the Palmdale Plant 42 Heritage Airpark is an aviation museum and airpark located in Palmdale, California with various United States military aircraft on display. The park i ...
in Palmdale, California.
See also
References
External links
{{X-planes
X-055
2000s United States experimental aircraft
Twinjets
High-wing aircraft
T-tail aircraft
Air Force Research Laboratory projects
Aircraft first flown in 2009