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 wings.
A monoplane has inherently the highest efficiency and lowest drag of any wing config ...
,
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 struts, 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 flig ...
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 Aircraft flight control system, conventional three-a ...
that was designed by
Volmer Jensen and provided as plans for
amateur construction by his company
Volmer Aircraft Volmer may refer to:
People Surname
* Arvo Volmer (born 1962), Estonian conductor
* Hardi Volmer (born 1957), Estonian film director, puppet theatre set decorator and musician
* Joost Volmer (born 1974), Dutch footballer
* Max Volmer (1885–1965) ...
of
Glendale, California
Glendale is a city located primarily in the Verdugo Mountains region, with a small portion in the San Fernando Valley, of Los Angeles County, California, United States. It is located about north of downtown Los Angeles.
As of 2024, Glendale ha ...
.
[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 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 (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...
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 struts, which act in ...
. The
fuselage
The fuselage (; from the French language, French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds Aircrew, crew, passengers, or cargo. In single-engine aircraft, it will usually contain an Aircraft engine, engine as wel ...
is built around a keel tube that mounts the
cruciform tail
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 tailplane, 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, mounted in
tractor configuration
In aviation, a tractor configuration is a propeller-driven fixed-wing aircraft with its engine mounted with the propeller in front, so that the aircraft is "pulled" through the air. This is the usual configuration; the pusher configuration ...
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 taxiing, takeoff or landing. For aircraft, it is generally needed for all three of these. It was also formerly called ''alighting gear'' by some manufacturers, s ...
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 ...
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 (Currency symbol, symbol: Dollar sign, $; ISO 4217, currency code: USD) is the official currency of the United States and International use of the U.S. dollar, several other countries. The Coinage Act of 1792 introdu ...
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, fixed-wing 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