The MFI BA-12 Sländan is a single seat
ultralight
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 aile ...
of pod and high boom configuration and with a
butterfly tail. It was designed and built in
Sweden in the 1980s and led to a two-seat, slightly larger, development called the BA-14.
Design and development
The Sländan ( en, Dragonfly) was the first Swedish microlight apart from glider based types. It is built from
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, with a square section beam formed in two halves supporting the engine well ahead of the wing
leading edge
The leading edge of an airfoil surface such as a wing is its foremost edge and is therefore the part which first meets the oncoming air.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, ...
and extending aft continuously to the tail. The wings, rectangular in plan and with a high
aspect ratio (10:1), are attached to the beam with
dihedral of 1.5°.
Aileron
An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement arou ...
s cover 30% of the
trailing edge
The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge meets.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 521. Aviation Supplies & Academics, 199 ...
. The wing has two pressed
spar
SPAR, originally DESPAR, styled as DE SPAR, is a Dutch multinational that provides branding, supplies and support services for independently owned and operated food retail stores. It was founded in the Netherlands in 1932, by Adriaan van Well ...
s,
foam
Foams are materials formed by trapping pockets of gas in a liquid or solid.
A bath sponge and the head on a glass of beer are examples of foams. In most foams, the volume of gas is large, with thin films of liquid or solid separating the ...
filled
glass fibre
Glass fiber ( or glass fibre) is a material consisting of numerous extremely fine fibers of glass.
Glassmakers throughout history have experimented with glass fibers, but mass manufacture of glass fiber was only made possible with the inventio ...
rib
In vertebrate anatomy, ribs ( la, costae) are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the ch ...
s and
Kevlar
Kevlar (para-aramid) is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, the high-strength material was first used commercially in the early 1970s ...
filled glass fibre
sandwich
A sandwich is a food typically consisting of vegetables, sliced cheese or meat, placed on or between slices of bread, or more generally any dish wherein bread serves as a container or wrapper for another food type. The sandwich began as a po ...
skins. The butterfly tail surfaces are also rectangular and assisted by a short ventral fin with the same
chord
Chord may refer to:
* Chord (music), an aggregate of musical pitches sounded simultaneously
** Guitar chord a chord played on a guitar, which has a particular tuning
* Chord (geometry), a line segment joining two points on a curve
* Chord ( ...
as the
tailplane
A tailplane, also known as a horizontal stabiliser, is a small lifting surface located on the tail (empennage) behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed-wing aircraft such as helicopters and gyroplan ...
.
[
The round nosed, single seat cabin is formed from six bonded pieces and mounted on the boom with its windscreen at the wing ]leading edge
The leading edge of an airfoil surface such as a wing is its foremost edge and is therefore the part which first meets the oncoming air.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, ...
, placing the pilot below the wing at about one quarter chord. The sides are normally open though complete enclosure is an option. On each side a forward leaning bracing strut
A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension.
Human anatomy
Part of the functionality o ...
runs from the lower rear cabin to the front wing spar. The Sländan has a short, fixed, tricycle undercarriage
Tricycle gear is a type of aircraft undercarriage, or ''landing gear'', arranged in a tricycle fashion. The tricycle arrangement has a single nose wheel in the front, and two or more main wheels slightly aft of the center of gravity. Tricycle ...
with a steerable nosewheel; the mainwheels, fitted with brakes, are mounted on straight steel cantilever
A cantilever is a rigid structural element that extends horizontally and is supported at only one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cant ...
legs from the lower fuselage. There is a protective tailskid
Conventional landing gear, or tailwheel-type landing gear, is an aircraft undercarriage consisting of two main wheels forward of the center of gravity and a small wheel or skid to support the tail.Crane, Dale: ''Dictionary of Aeronautical Term ...
on the tip of the underfin.[
The prototype Sländan was initially powered by a (21 kW) (28 hp) ]König SD 570
The König SD 570 is a four-cylinder, two-stroke, single ignition radial aircraft engine designed for powered paragliders, powered parachutes and single place ultralight trikes.Cliche, Andre: ''Ultralight Aircraft Shopper's Guide'' 8th Editio ...
4-cylinder two-stroke
A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of t ...
engine though there were plans to replace this with a Lotus Magnum 2.25 when this type became available.[ At least three examples have been fitted with ]Rotax
Rotax is the brand name for a range of internal combustion engines developed and manufactured by the Austrian company BRP-Rotax GmbH & Co KG (until 2016 BRP-Powertrain GmbH & Co. KG), in turn owned by the Canadian Bombardier Recreational Produ ...
engines.[
The Sländan first flew in 1984 and by February 1985 MFI were assembling five more. It was agreed that later aircraft should be produced by the ]Royal Swedish Aero Club Royal Swedish Aero Club ( sv, Kungliga Svenska Aeroklubben, abbreviated KSAK, previously ''Svenska Aeronautiska Sällskapet'', abbreviated SAS), established in 1900, is today the national organization for Sweden's over 150 flying clubs and have by ...
using MFI's moulds and tools. It was intended to market the Sländan in both flyaway and kit form. At about the same time, in a collaboration between MFI and FFK Aerotech, Andreasson was developing a slightly larger, two seat version called the FFV Aerotech BA-14 Starling __NOTOC__
The FFV Aerotech BA-14 Starling is a Swedish two-seat light monoplane designed by Björn Andreasson and developed as a joint venture between Malmo Forsknings & Innovations and FFV Aerotech.
Design and development
The prototype Starling ...
.[
]
Operational history
Three Rotax powered, Swedish registered Sländans appear on the mid-2010 civil aircraft registers of Europe excluding Russia.[
]
Aircraft on display
Sländan ''SE-YKA'' is on display at the ''Aeroseum'' at Gothenburg City Airport
Gothenburg (; abbreviated Gbg; sv, Göteborg ) is the second-largest city in Sweden, fifth-largest in the Nordic countries, and capital of the Västra Götaland County. It is situated by the Kattegat, on the west coast of Sweden, and has a ...
.[
]
Variants
;BA-12 Sländan: Single seat version.
;FFV Aerotech BA-14 Starling: Side-by-side version with 48 kW (65 hp) Rotax 532
The Rotax 532 is a two-stroke, two-cylinder, rotary valve engine, liquid-cooled, gear reduction-drive engine that was formerly manufactured by BRP-Rotax GmbH & Co. KG. It was designed for use on ultralight aircraft.Raisner, William: ''LEAF cata ...
engine. Wing span increased by 1.0 m. (3 ft 3 in) with more rounded tips. Flaps added. Tailplane span also increased and tips rounded, with horn balanced elevators.
Specifications (BA-12 Sländan)
References
{{DEFAULTSORT:MFI BA-12 Slandan
1980s Swedish civil aircraft
Ultralight aircraft
Single-engined tractor aircraft
High-wing aircraft
V-tail aircraft
Aircraft first flown in 1984