Newsletter 8 – September 2003

Welcome to Newsletter No. 8, in this issue we feature the following.

  • Flutter Tests – Some background Information
  • The NEW Pipistrel Factory
  • Pipistrel Demonstration Team
  • “Flight for Sight” Update

August and September have been busy months for Pipistrel, besides all the normal work with production and product development we participated at Slovenia’s first Aero-Expo as the prime exhibitor with both Sinus and Virus Ultralight Motorgliders presented at the site, we have conducted further ground aero-elasticity (flutter) tests for both aircraft and started works at the construction site for the new factory facilities at the Ajdovscina airport.

Flutter tests
In the week of August 25th the old hangar at the Ajdovscina airport was crowded with wires and high-tech equipment as Professor Norbert Niedbal, the leading expert on aero-elasticity and vibrations made preparations for the ground flutter test of Sinus Ultralight Motorglider and Virus 912. The purpose of these tests was to show that there is no risk of flutter (aerodynamic resonance) inside the aircraft’s normal operational speed range and to qualify the aircrafts speed at heavier MTOW’s.Pictures show Sinus and Virus equipped with many sensors which are in fact miniature acceleration gauges; these are connected to recording units.
Virus wing and Aileron being ‘excited’ during testing
Virus tail being ‘excited’ during testing
Even the propeller underwent testing


The whole aircraft and its airframe are isolated from the ground by placing air mattresses under the wheels and various parts of the aircraft are excited by a vibration system.


Professor Norbert Niedbal recording from several hundred sensors
Exciting the Horizontal Stabiliser and Rudder
Laying out the hundreds of sensors for testing
The finished job, several hundred sensors on the wing of the Sinus

The ultimate goal with this additional flutter testing is to find eigen-frequencies of the aircraft structure and control surfaces and then project the measured values into a flutter critical speed. This requires extensive and complex calculations to be done after all the data has been obtained. The measurement process required three full days of hard work and the test results will qualify the aircraft for the higher MTOW required for Australian and the USA markets.

Foundations laid for the new Pipistrel factory facility

September 5th was the day when Ivo Boscarol and Pipistrel made history. After years of negotiations the construction of the new Pipistrel Factory facility has begun.


A large number VIP’s attended the ceremony, among them the Minister of Economy, the President of the Aeronautical Association of Slovenia, the chairman of Slovenia’s Board of Commerce and Mayor of Ajdovscina. The new factory will enable the Pipistrel team to take full advantage of more than 2000 sq. meters of assembly space and boost the production from the existing 4 aircraft per month to 8-10 per month.

Pipistrel’s revolutionary self-launching two-seater ultralight glider Taurus to be introduced in spring 2004 will also be manufactured in the new facility.
Ivo Boscarol, the founder and General Manager of Pipistrel d.o.o. together with Mrs. Tea Pertin, Minister of Economy, setting the “first piece” of the foundations of Pipistrel’s new factory at Ajdovscina Airport.
The VIPs at the ceremony, being entertained by Tomaz Domicelj,
a famous Slovenian musician and Ivo’s great friend.

Pipistrel Demonstration Team

In 2003, the Pipistrel Demonstration Team was established. The team consists of three Virus 912 aircraft which are displayed in all their beauty, gracefully flown in close formation.

Leading the formation (Virus S5-PCA) is Mr. Valter Faganelj, an experienced flight instructor with military experience. Following him on the left-hand side (Virus S5-PBR) is Mr. Dejan Kavcic, also a flight instructor with long years of experience with Ultralight aircraft. On the right-hand side (Virus S5-PCP) flies Tine Tomazic, Pipistrel’s factory test and demonstration pilot, who also flies the team’s solo.

So far, the team performed at 2 major airshows in Slovenia, the Ultralight Nationals RAL-1 and RAL-2 and on several other occasions, also the ceremony for the new Pipistrel’s factory. In the remaining of the season, the team remains busy performing across Slovenia.Tine Tomazic was the pilot who wowed the crowds at Australia’s Natfly 2003 at Narromine last Easter, people are still talking about his performance.

Flight for Sight Update
Plans are well underway for the upcoming “Flight for Sight” event around rural Queensland with a Sinus and Virus aircraft. With departure on the 7th October looming all the final preparations are well underway, major sponsors have come on board providing the event with satellite communications, fuel, accommodation and many other vital essentials.The aim of the event is to raise awareness of vision impairment in rural Queensland and raise much needed funds for the Royal Blind Federation; our target is to reach $20,000.

Our thanks go to Australian Ultralights who have run a picture on the cover and a double page colour feature inside to help raise awareness for this event.Any additional assistance or donations would be greatly appreciated, please contact the Royal Blind Federation on

Till next time… Safe Flying Michael Coates