The Volmer VJ-24W SunFun is an American
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 confi ...
,
strut-braced
In aeronautics, bracing comprises additional structural members which stiffen the functional airframe to give it rigidity and strength under load. Bracing may be applied both internally and externally, and may take the form of strut, which act in ...
, single-seat, pod-and-boom
motor glider
A motor glider is a fixed-wing aircraft that can be flown with or without engine power. The FAI Gliding Commission Sporting Code definition is: a fixed-wing aerodyne equipped with a means of propulsion (MoP), capable of sustained soaring flight ...
and
ultralight aircraft
Ultralight aviation (called microlight aviation in some countries) is the flying of lightweight, 1- or 2-seat fixed-wing aircraft. Some countries differentiate between weight-shift control and conventional three-axis control aircraft with ailer ...
that was designed by
Volmer Jensen and provided as plans for
amateur construction by his company
Volmer Aircraft Volmer may refer to:
People
* Arvo Volmer
Arvo Volmer (born November 4, 1962 in Tallinn) is an Estonian conductor.
Volmer was principal conductor of the Estonian National Symphony Orchestra from 1993 to 2001. From 2004 to 2013 he was Chief Cond ...
of
Glendale, California
Glendale is a city in the San Fernando Valley and Verdugo Mountains regions of Los Angeles County, California, Los Angeles County, California, United States. At the 2020 United States Census, 2020 U.S. Census the population was 196,543, up from ...
.
[Purdy, Don: ''AeroCrafter - Homebuilt Aircraft Sourcebook'', page 315. BAI Communications, July 1998. ][Rogers, Bennett: ''1974 Sailplane Directory, Soaring Magazine'', page 100. Soaring Society of America, August 1974. USPS 499-920][Cliche, Andre: ''Ultralight Aircraft Shopper's Guide'' 8th Edition, page E-43. Cybair Limited Publishing, 2001. ]
Design and development
The SunFun started as a foot-launched glider design, the VJ-24, and was developed into a wheeled
undercarriage
Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include:
*The landing gear of an aircraft.
*The ch ...
motor glider, the VJ-24W. The VJ-24 was derived from the earlier
Volmer VJ-23 Swingwing
The Volmer VJ-23 Swingwing is an American high-wing, single-seat, foot launched glider that was designed by Irv Culver and built by Volmer Jensen and supplied as plans by his company Volmer Aircraft for amateur construction. Kits were also a ...
and differed from that design by replacing the wooden structure with metal and employing a constant chord, strut-braced wing in place of the VJ-23's cantilever, tapered wing.
The aircraft is built from
aluminium
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...
tubing covered with
aircraft fabric
Aircraft fabric covering is a term used for both the material used and the process of covering aircraft open structures. It is also used for reinforcing closed plywood structures. The de Havilland Mosquito is an example of this technique, as are ...
. The span wing is braced by V-struts, supported by triangular
jury struts
In aeronautics, bracing comprises additional structural members which stiffen the functional airframe to give it rigidity and strength under load. Bracing may be applied both internally and externally, and may take the form of strut, which act in ...
. 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 ...
is built around a keel tube that mounts the
cruciform tail __NOTOC__
The cruciform tail is an aircraft empennage configuration which, when viewed from the aircraft's front or rear, looks much like a cross. The usual arrangement is to have the horizontal stabilizer intersect the vertical tail somewhere ...
at the aft end, the wing and cockpit in the center and the engine at the front. The specified engines are the
Yamaha KT100 go-kart powerplant and the
McCulloch MAC-101
The McCulloch MAC-101, also called the MC-101 and MC101, is a two-stroke, single cylinder engine that was designed and produced by McCulloch Motors Corporation for kart racing
Kart racing or karting is a road racing variant of motorsport with ...
, mounted in
tractor configuration
In aviation, the term tractor configuration refers to an aircraft constructed in the standard configuration with its engine mounted with the propeller in front of it so that the aircraft is "pulled" through the air. Oppositely, the pusher c ...
on the front of the keel tube, above the aircraft's nose. The
landing gear
Landing gear is the undercarriage of an aircraft or spacecraft that is used for takeoff or landing. For aircraft it is generally needed for both. It was also formerly called ''alighting gear'' by some manufacturers, such as the Glenn L. Martin ...
is of
conventional configuration, using
spoke
A spoke is one of some number of rods radiating from the center of a wheel (the hub where the axle connects), connecting the hub with the round traction surface.
The term originally referred to portions of a log that had been riven (split l ...
d bicycle wheels for the main gear. Pilot weight is limited to .
The take-off and landing distances with the engine are both .
In 1998 plans cost
US$
The United States dollar (symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, to distinguish it from other dollar-denominated currencies; referred to as the dollar, U.S. dollar, American dollar, or colloquially buck) is the official ...
100 and the estimated cost of the materials to build the VJ-24W were US$2400. The estimated construction time is 250 hours.
Variants
;VJ-24
:Unpowered three axis-controlled
hang glider
Hang gliding is an air sport or recreational activity in which a pilot flies a light, non-motorised foot-launched heavier-than-air aircraft called a hang glider. Most modern hang gliders are made of an aluminium alloy or composite frame covered ...
version, foot launched and landed.
Glide ratio
In aerodynamics, the lift-to-drag ratio (or L/D ratio) is the lift generated by an aerodynamic body such as an aerofoil or aircraft, divided by the aerodynamic drag caused by moving through air. It describes the aerodynamic efficiency under give ...
is 9:1 at and minimum sink is 180 fpm.
;VJ-24W
:Powered version with wheeled landing gear.
Specifications (VJ-24W)
See also
References
External links
Photo of a VJ-24W CockpitPhoto of a VJ-24W TailPhoto of a VJ-24W
{{Volmer Jensen aircraft
1970s United States sailplanes
Homebuilt aircraft
Sailplanes designed for foot-launching
Motor gliders
VJ-24
High-wing aircraft
1970s United States ultralight aircraft