The Barel Graal (English: ''Grail'') is a French
mid-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 confi ...
,
T-tail
A T-tail is an empennage configuration in which the tailplane is mounted to the top of the fin. The arrangement looks like the capital letter T, hence the name. The T-tail differs from the standard configuration in which the tailplane is ...
ed single-seat
motor glider that was designed by
Max Barel and produced by
Graal Aéro as a complete ready-to-fly aircraft or as a kit for
amateur construction.
[Bertrand, Noel; Rene Coulon; et al: ''World Directory of Leisure Aviation 2003–04'', page 56. Pagefast Ltd, Lancaster OK, 2003. ISSN 1368-485X]
Design and development
The Graal was designed as a low-cost,
self-launching FAI 15 Metre Class
Competition classes in gliding, as in other sports, mainly exist to ensure fairness in competition. However the classes have not been targeted at fostering technological development as in other sports. Instead classes have arisen because of:
* t ...
motorglider that conforms to the French and
Fédération Aéronautique Internationale
The (; FAI; en, World Air Sports Federation) is the world governing body for air sports, and also stewards definitions regarding human spaceflight. It was founded on 14 October 1905, and is headquartered in Lausanne, Switzerland. It maintai ...
ultralight rules. Because of the low
wing loading imposed by the ultralight rules it was not intended to be a competitive sailplane, but to be used for recreational
soaring
Soaring may refer to:
* Gliding, in which pilots fly unpowered aircraft known as gliders or sailplanes
* Lift (soaring), a meteorological phenomenon used as an energy source by some aircraft and birds
* ''Soaring'' (magazine), a magazine produced ...
. It was first flown on 2 February 2002.
The aircraft is made from
composites and features an unusual tail configuration. The
fuselage
The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...
joins the T-tail halfway up 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 ...
. The folding three-bladed propeller is mounted at the rear of the fuselage and so the lower half of the fin protects the propeller from contacting the ground. The twin cylinder
RDM 200 engine is mounted inside the fuselage, just behind the pilot, using trap doors for cooling and exhaust. The engine drives the tail-mounted propeller through an extension shaft. The propeller folds automatically when the engine is shut down due to
aerodynamic drag
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fl ...
and also deploys automatically on engine start by
centrifugal effect as it starts to spin. A fuselage mounted fuel tank holds . The Graal has a semi-tapered wing with a span that features top and bottom
dive brakes, full-span
flaperons and employs an Eppler E668
airfoil
An airfoil (American English) or aerofoil (British English) is the cross-sectional shape of an object whose motion through a gas is capable of generating significant lift, such as a wing, a sail, or the blades of propeller, rotor, or turbine.
...
. Landing gear is a retractable
monowheel gear and the aircraft has a
ballistic parachute.
The Graal disassembles and is transported in a lightweight trailer.
In 2002 the company indicated the aircraft cost €35000 for a complete ready-to-fly aircraft and €21000 for a quick-build kit.
Specifications (Graal)
See also
References
External links
*{{Official website, http://www.graal-aero.fr
Photos of the prototype Graal
2000s French sailplanes
Homebuilt aircraft
T-tail aircraft
Motor gliders
Aircraft first flown in 2002
Single-engined pusher aircraft