Newsletter 19 – June 2004

Welcome to Newsletter 19, thank you for all the positive feedback on the Taurus, I have been asking the factory for more information to fulfill the requests from interested pilots and its timely the factory have released an update on the testing and some background information on the Pipistrel Company and the Taurus project which makes for interesting reading. I am sure you will enjoy……

US Customers Can Save $$$      We also have a Sinus and a Virus aircraft headed off to Oshkosh Airventure for static display, should you be interested in saving a few $$ please drop me an email for details and pricing, they will be delivered straight after the show to anywhere in the US.

Sport Pilot Back and Running – Great News…. Sport Pilot has been returned to the OMB for what is hoped by many to be the final review before publication. Industry chatter suggests the rule will be released at Oshkosh… lets hope so.

Official Taurus Press Release


Pipistrel d.o.o. Ajdovščina is the most versatile and complex microlight aircraft producer in the World. The company incorporates everything from design to complete manufacture of aviation propellers, trikes and microlight aircraft of world-class quality other producers envy. It was in 1995 when Pipistrel d.o.o. Ajdovščina introduced the then unprecedented Sinus two-seat microlight which was dedicated not only microlight pilots to glider pilots. The idea to design and produce the Sinus was triggered by an increasing number of glider pilots, who wanted to fly cheaper and above all be independent from glider towing.

The Idea

In 1995 ‘normal’ pilots general opinion about their microlight colleagues was not too good. They believed microlight pilots would not to be capable of piloting such a high-performance aircraft that resembled a glider . The idea of producing a microlight aircraft with a ‘glider soul’ seemed rather bold, but as it turned out the owner of Pipistrel and co-constructor of the Sinus, Ivo Boscarol was right; proving this are 150 Pipistrel aircraft that now successfully and safely fly on each and every of the Worlds continents. The Sinus, the worlds first ultralight motorglider and her younger sister Virus have launched the name of Pipistrel and Slovenia into the world markets and are now synonymous for exceptional flight characteristics and unparalleled quality of finish.

The development of an aircraft is a huge project which requires experts from all branches. To develop a never-seen-before concept of an aircraft was even a great challenge. With the Sinus, the team aimed at the following…..

  • To design a two-seat composite-built aircraft with 15 meters of wingspan, which requires 100 meters of runway to take-off and reaches 200 km/h in horizontal flight, all on a 50 HP engine
  • The aircraft must be completely safe – intended for gliding it is constructed according to JAR-22 rules (classic gliders), although it fits into the microlight category
  • The aircraft must have a comfortable cockpit with seats in side-by-side configuration, since microlight pilots rarely fly alone
  • The aircraft must provide a low stall speed and at the same time be a high speed cruiser – this enables the pilots to go gliding over terrains away from their home base without the need of road transport
  • The L/D ratio of the aircraft must be 1:30, which makes it a decent glider and provides extra safety in case of engine failure
  • The aircraft must be equipped with airbrakes, which enable the pilot do descent rapidly and use a high angle of approach onto typical ultralight airfields – short runways with plenty of obstacles below the approach path
  • The aircraft must fully comply with all criteria of a microlight – the reason for this is inexpensive maintenance and pilots who cannot be issued an aviation medical certificate any more can fly the aircraft. Many countries issue a microlight licence on basis of only a driver’s licence.

The Pipistrel team eventually managed to combine all desired features into an aircraft which at first seemed impossible. The Sinus became a reality and flew for the first time and It was not too long before glider pilots, who were willing to trade the imperfect glide ratio for the low cost of flying, freedom and independence from glider tow, began placing orders. The Sinus became an instant hit worldwide, she took the World Champion 2001 title, triggered a wave of imitators and set new foundations for a new category within the definition of microlights.

The Taurus

After such a success it was quite realistic to expect there is also a market niche for a real microlight two-seat glider, as well as it’s version with an auxiliary, fully retractable engine.

This time, the main idea of construction was completely different from the one with Sinus, but the aims remained sky-high. The world’s first two-seat glider, later named Taurus is to…..

  • Offer pilots a REAL glider or it’s self-lauchable version with an auxiliary, yet fully retractable engine and glide ratio of at least 1:40
  • Make gliding cheap
  • Provide a fully equipped aircraft, including a parachute rescue system, all instruments, radio etc. at a reasonable price
  • Provide the owner with complete freedom and independence –even the helper holding the wing tip during take-off is now not needed any more
  • Have the most comfortable cockpit on the market with a separate ventilation system for each pilot
  • Be pilot-friendly oriented with simple & straight-forward systems handling.

In order to reduce development costs, Pipistrel decided to fit the Taurus with an already existing wing, which proved to be excellent on Sinus and single-seat ultralight glider Apis. The fuselage of Taurus has however been developed and shaped from scratch. Using special lifting body shape concept it features enough room for an auxiliary, yet fully retractable engine and an incredibly spacious cockpit.


It was not easy to decide how to shape the pilots workspace, but in the end the fact that World’s population is growing in all measures prevailed. The pilots in the Taurus are placed side-by-side for comfort and ease of communication. Furthermore, this kind of seat placement saves some weight, since some of the control systems do not have to be made separately. Taurus is also intended for training, therefore all control levers must be within reach of both pilots.


Both pilots have individual control sticks and rudder pedals with hydraulic wheel brakes levers. The landing gear operation lever, flaps, airbrakes and trim levers are for joint use of both pilots and therefore found in the middle, between both seats. The instrument column not only fits all instruments, but also the throttle push-lever, choke lever, tow-rope disconnection handle, ventilation handle and engine retraction system interface. All handles and levers ensure sensitive, yet reliable aircraft systems handling. For added comfort pilots enjoy adjustable headrests, adjustable rudder pedals, separate vent window for each pilot and along with a central ventilation system for efficient de-fogging of glass surfaces. The canopy is a moulded single transparent plexi piece with no support columns. The entrance to the cockpit is therefore simple and unobstructed as is the visibility out of the cockpit in all flight stages.

Retractable engine

The version of Taurus with an auxiliary retractable engine comes with a ROTAX 503 twin carburated engine which drives a Pipistrel propeller. This power configuration provides the aircraft with short-field takeoff and very decent climb performance. The system for extending and retracting the engine and propeller is fully automated. The pilots takes advantage of a dedicated interface on the instrument column and all he/she has to do is to flick the switch to ‘Engine IN’ or ‘Engine OUT’ position – everything else is done completely automatically. When retracting, the propeller is first positioned vertically, the engine then gets retracted and the covers close. To restart the engine on ground or in-flight the pilot selects the ‘engine OUT’ option and the engine extends & starts-up all by itself after the covers had been opened. The entire engine retraction system is incredibly light and reliable, all switches and sensor used to monitor the operations are electromagnetic-induction type and as such not sensitive to vibration, mechanical damage and/or dirt.


Taurus has a taildragger undercarriage. The two main, retractable wheels are equipped with separate hydraulic brake system for easy ground handling. The undercarriage retracting system is fully mechanic but only needs very light forces on the cockpit lever during operation. The tail wheel is not retractable but fully steerable, which makes taxiing a walk in the park.

Other systems

The Taurus comes equipped with a rocket charged parachute rescue system which is fired out of the fuselage in case of extreme emergency. The parachute opens instantly and the aircraft slowly descents to the ground without the pilots leaving their seats. Furthermore, the aircraft is not additionally damaged by use of rescue system; the cabin and pilots remain completely intact.

The airbrakes, flaps, trim and their drives are all mechanical and identical to the ones used in Sinus.

One can also take-off with the Taurus being towed behind a tow-plane as there is a tow-hook with disconnection mechanism on board.

One of the particularities is the mass trim system. There are two fluid reservoirs in the aircraft, one in the nose and one in the tail section. Since both pilots sit in front of the CofG, the CofG range can move quite considerably. In case only one pilot is on board, the trim fluid is pumped into the front reservoir, should there be 2 persons on board, the trim fluid is pumped into the tail section. By using the mass trim system the aircraft becomes safe and insensitive to big differences in pilot weights, additionally the unpleasant carrying and insertion of metal weights is eliminated.

Technical data and provisional flight characteristics

Aircraft model
max. output (2 carb.) 53 HP @ 6600 RPM
Twin blade Pipistrel – dia. 1600 mm
15.2 m
7.17 m
1.41 m
Wing area
12.33 m2
Vertical fin area
0.9 m2
Horizontal fin area
1.36 m2
Aspect ratio
Pos. flap settings
9 deg – 18 deg
Neg. flap setting
-5 deg
CofG safe range
22% – 41% MAC
Empty aircraft weight
279 kg
Minimum crew weight
60 kg
Max. crew weight
180 kg
Max take-off mass (MTOM)
472,5 kg
Fuel capacity
30 l
Usable fuel
27 l
Stall speed with flaps
33.7 knots
Stall speed clean
35.4 knots
Manoeuvring speed
73 knots
Max. speed with flaps
70 knots
Max. speed with airbrakes
86 knots
Max. operational speed
110 knots
121 knots
Minimum sink
128 fpm
Minimum sink speed
43 knots
Max. sink with airbrakes
1082 fpm
Best glide ratio
Best glide ratio speed
59 knots
Glide ratio at 75 knots
Glide ratio at 97 knots
Max. speed in tow
81 knots
45°- 45° roll time
3,9 s
Take-off distance at MTOM
115 m
Take-off dist. over 15 m obstacle at MTOM
230 m
Cruise speed at 75% power
78 knots
Best climb speed
59 knots
Best climb at MTOM
767 fpm
Ceiling MTOM
22,300 feet
Max. service load (safety factor 1,8)
+4g -2g
Max. tested load
+ 7.2g – 7.2g
Consumption at cruise speed
12 lph

Note: all data is subject to change without notice and is based on preliminary flight testing.

Polar Graph

Speed polar in clean glider configuration (gear & engine retracted, MTOM)

The development team are…

  • Ivo Boscarol – Idea, basic concept, some mechanic parts, ballast system
  • Ing. Franco Orlando – Aerodynamic calculations
  • Ing. Radivoj Kikelj – Structural calculations
  • Ing. Franci Popit – Mechanic solutions, undercarriage
  • Saao Kolar – Composites
  • Valter Mauri – engine mount
  • Igor Strumbelj – Engine automation processor
  • LX navigation – Instruments
  • Elvis Terbizan – Electric systems
  • Boris Velikonja – Production manager

Serial production will start in October 2004, initially with 1 aircraft per month, increasing up to 4 per month by the end of next year.

The cost of development was 400.000 EUR and it was financed solely by Pipistrel.

As always please come back to me with any questions.

Take care Michael Coates