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 jet engine, 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. F ...
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
Air cargo is any property carried or to be carried in an aircraft. Air cargo comprises air freight, air express and airmail.
Aircraft types
Different cargo can be transported by passenger, cargo or combi aircraft:
* Passenger aircraft use the ...
-carrier capabilities using advanced
composite material
A composite or composite material (also composition material) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or physical properties and are merged to create a ...
s. A project of the
United States Air Force
The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...
's
Air Force Research Laboratory
The Air Force Research Laboratory (AFRL) is a scientific research and development detachment of the United States Air Force Air Force Materiel Command, Materiel Command dedicated to leading the discovery, development, and integration of direct- ...
, it was built by the international aerospace company
Lockheed Martin
The Lockheed Martin Corporation is an American Arms industry, defense and aerospace manufacturer with worldwide interests. It was formed by the merger of Lockheed Corporation with Martin Marietta on March 15, 1995. It is headquartered in North ...
, 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, highly classified research and developme ...
'') facility in
Palmdale, California
Palmdale is a city in northern Los Angeles County, California, United States. The city lies in the Antelope Valley of Southern California. The San Gabriel Mountains separate Palmdale from the Los Angeles Basin to the south.
On August 24, 1962 ...
.
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 wings.
A monoplane has inherently the highest efficiency and lowest drag of any wing config ...
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 (AFS) is an American aviation and aeronautics research subsidiary of Boeing that specializes in special-purpose unmanned aerial vehicles. Aurora's headquarters is at Manassas Regional Airport.
History
In 1989, AFS was ...
' design based on the
Antonov An-72
The Antonov An-72 (NATO reporting name: Coaler) is a Soviet transport aircraft, developed by Antonov. It was designed as a STOL transport and intended as a replacement for the Antonov An-26, but variants have found success as commercial freigh ...
in 2007. The aircraft is powered by two
Pratt & Whitney Canada
Pratt & Whitney Canada (PWC or P&WC) is a Canada-based aircraft engine manufacturer. PWC's headquarters are in Longueuil, Quebec, south of Montreal. It is a division of the larger US-based Pratt & Whitney (P&W), itself a business unit of RTX ...
PW306B turbofan
A turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft engine, aircraft propulsion. The word "turbofan" is a combination of references to the preceding generation engine technology of the turbojet and the add ...
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 ( UK/IUPAC) or aluminum alloy ( NA; 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 ...
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
Out of autoclave composite manufacturing is an alternative to the traditional high pressure autoclave (industrial) curing process commonly used by the aerospace manufacturers for manufacturing composite material. Out of autoclave (OOA) is a pro ...
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, sta ...
. 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
As of September 12, 2014, the X-55 aircraft is on display at the
Joe Davies Heritage Airpark 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
Aircraft with retractable tricycle landing gear