| Virus | ||
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The Virus 912 is similar to the Sinus range except it only comes fitted with the Rotax 912 engine. It's wingspan, at 12.46 m (40' 10½"), is smaller than the Sinus and this makes the aircraft fly faster but the compromise is a reduced glide ratio.
The Virus is equipped with steerable nose wheel or tailwheel as an option.
The Virus is a very capable touring aircraft. With long range tanks it has 7 hours endurance at 120 knots and with a higher wing loading it cuts through heavy turbulence with ease.
From A-to-B the Virus is certainly an efficient and economical aircraft, but dont let this fool you - slope soaring is a breeze in the Virus. The fast roll rate and excellent visibility make it a substantial wave or slope soaring aircraft and with a glide ratio of 24:1 it can still be thermaled. Overall, the Virus is an extremely nice package which will fit in most hangars.
| MODEL |
VIRUS 912
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| ENGINE ROTAX | ROTAX 912 UL2 |
| max power(with 2 carb.) | 80 hp at 5500 rpm |
| PROPELLER | Pipistrel VARIO |
| SIZES | |
| wing span | 12.46 m 40' 10½" |
| length | 6.4 m 20.99 ft |
| height | 2.00 m 6.56 ft |
| wing area | 11.0 m2 118.41 ft2 |
| rudder area | 1.1 m2 11.84 ft2 |
| tail area | 1.63 m2 17.55 ft2 |
| aspect ratio | 13.1 |
| positive flaps | 10 deg. 18 deg |
| negative flaps | 5 deg |
| center of gravity | 25% - 37% |
| WEIGHTS | |
| empty weight | 285 kg 628 pounds |
| max take off weight (MTOW) | 560 kg 1235 Pounds |
| fuel tanks capacity | 2 x 30 l or 2 x 50 l 2x7.93 or 2x13.2 US G 2x6.6 or 2x11 Imp G |
| useful fuel | 57 litres or 97 litres |
| PERFORMANCES | |
| stall with flaps | 64 km/h 34.6 Knots 39.8 MPH |
| stall without flaps | 74 km/h 39.9 Knots 46.0 MPH |
| cruising speed | 225 km/h 121.5 Knots 139.8 MPH |
| max speed with airbrakes out | 160 km/h 86.4 Knots 99.4 MPH |
| max speed with flaps down | 130 km/h 70.2 Knots 80.8 MPH |
| manoeuvring speed | 135 km/h 73.0 Knots 83.9 MPH |
| max. horizontal speed | 238 km/h 128.5 Knots 147.9 MPH |
| VNE | 250 km/h 135.0 Knots 155 MPH |
| best climb speed | 130 km/h 70.2 Knots 80.8 MPH |
| max climb rate (MTOW) | 6.2 m/sec 1220 fpm |
| climb rate at 140 km/h | 7.0 m/sec 1378 fpm |
| min.sink speed | 96 km/h 48.6 Knots 60.0 MPH |
| min.sink (prop. 90 deg.) | 1.72 m/sec 338 fpm |
| max. sink with airbrakes | 5.5 m/sec 1082 fpm |
| best glide ratio speed | 110 km/h 59.4 Knots 68.4 MPH |
| best glide (prop. 90 deg.) | 1:24 |
| glide at 150 km/h (prop 90 deg) | 1:15 |
| take off run MTOW | 96 m 315 ft |
| take off over 15 m MTOW | 155 m 508 ft |
| service ceiling MTOW | 8100 m 26500 ft |
| 45°- 45° roll time | 3.1 sec |
| endurance | 5.6 hours |
| range distance | 1260 km 680 N Miles |
| max load factor permitted (x1.8) | +4g - 2g |
| max load factor tested | + 7.2g - 7.2g |
| fuel consumption at cruise speed | 9.7 l/hour |
| ERGONOMICS | |
| cabin width | 110 cm 43 1/3 inches |
| Max Pilot Height | +195 cm + 6' 4" |
Virus Flight Review by Phil Allen
A lot of people have been asking me for this so I thought I’d finally pull my finger out and do a review of my last 90 odd hours of flying in the Pipistrel Virus.
I should provide a bit of background before I go on to set the scene and let you know what my experience is.
My Background
I’ve flown quite a number of aircraft during my 11 year involvement in air sports. The following is a short list of the aircraft that I have had the pleasure of flying:
Hang Gliders
- Moyes Sonic
Gliders
- Blanik
GA
- Arrow III and IV
- Gazelle
- CT4
- Victa Airtourer
- Robin
- Decathlon
- Macchi Jets
Ultralights
- Sting
- Star
- X-Air
- Virus
- Sinus
- Dragonfly
I now have over 530 hours total aeronautical experience with around 270 in ultralights.
The Purchase
I was first introduced to the Virus by Michael Coates of X-Air and Sting notoriety. At the time I was without an aircraft and had his Sting ‘on loan’ to take to a couple of airshows on his behalf. I guess he just wanted his plane back so he was trying to get me to buy my own.
Delivering the Virus to Phil at Canberra Airport
The brochures and flight manual that he sent me showed the Virus and Sinus as reasonable aircraft, but after flying the sporty Sting I was initially reluctant to purchase a more conventional looking aircraft. I eventually decided to place a deposit on a Sinus and take a trip with Michael to Slovenia to check out the factory and test fly the plane. I was pretty impressed with the factory and the aircraft were impeccable. I later decided to change my order to a Virus, rather than the Sinus, because I prefer tricycle undercarriage and the sportier performance.
Flying in Slovenia
My first flight in the Virus was one that I shall never forget. The factory airfield is situated right below a picturesque cliff face which is absolutely fantastic for ridge soaring. I was lucky enough to fly with Tine, the factory test pilot, who really showed me the capabilities of the aircraft.
The aircraft is very ‘slippery’. With a clean skin, the aircraft easily picks up speed and is very economical. Because of the clean lines, the aircraft is fitted with spoilers above the wings to aid in descent and landing.
After some general flying to get a feel for the plane, Tine took over and began to show me how Slovenian pilots say ‘hello’ to their friends. The regulations in Slovenia are a little more relaxed than here in Australia and it is permissible to fly low, so Tine executed some high speed low level passes to demonstrate the aircraft’s performance.
After returning to the airfield so that I could fly solo for a while, we again took off for a demonstration flight. This time we lifted off, leveled at about 10 feet, increased speed to around 200 km/hr (roughly 110 kts) and then pulled up. Maintaining back pressure all the way, Tine executed a half loop and rolled off the top - quite an impressive maneuver without coming anywhere near the stall.
I had some more opportunities to fly solo in the valley and was really impressed by the performance of the aircraft in the cool conditions of Slovenia. I was still a little skeptical as to how the plane would perform in the heat that we have here in Australia but I was very much more comfortable with my purchase.
Australian Flying
Approximately eight months later my Virus finally arrived in Australia. I had to wait longer than usual because I changed my order from a Sinus to a Virus after Tine’s demonstration of this little aircraft’s capabilities.
On my aircrafts arrival, I set about checking all aspects of the Virus to familiarize myself with its limitations. This included draining the fuel tanks and accurately filling them to determine the exact fuel capacity and usable fuel. In the flight manual, the fuel capacity is specified as 57 liters of usable fuel. After filling at 2 and 5 liter increments, I found that each wing tank holds 35 liters with a half inch air gap at the top of the tank. This equates to approximately 68 liters of usable fuel – tested by running one tank completely empty and then refilling to determine fuel used. For safety I use 65 liters in all flight planning.
My first flights in Australia consisted primarily of circuit work around Canberra airport. Given the turbulent conditions regularly experienced in Canberra, I decided to pick a nice day and get my landings ‘squared away’ before I had to fly in the weather. In an hour I was doing spot landings that you could hardly feel in all configurations – one stage flap, two stages of flap, flapless, with and without using spoilers. The Virus is by far one of the easiest planes around to land.
My second flight started off nicely. I decided to head out towards Lake Bathurst and try some steep turns, stalls and gliding. Again, the aircraft performed flawlessly. The stall presented with no wing drop when negative, neutral or one stage of flap was selected and I experienced only a slight wing drop with two stages of flap. This was easily recovered with the ample rudder available. Surprisingly, a stall with spoilers extended is very similar to spoilers retracted with the main difference being a lower nose attitude on recovery. No additional wing drop is noticeable.
I set myself up for a glide by reducing speed to 65 knots, selecting one stage of flap, setting full fine pitch, and switching both magnetos off. For a person who has relied on an engine for so long, it’s a little disconcerting when solo and switching the engine off for the first time. The silence and peacefulness was simply breathtaking. I feathered the prop and turned into wind. I had a ground speed of a little over 20 knots with 65 knots IAS and I was descending at roughly 400’ per minute. I eased the stick back and settled on 59 knots – the optimum glide speed – and my descent reduced to around 200’ per minute.
After realizing I had been out for around 2 hours, I thought it time to head back home. The wind had picked up a little so I tightened my straps in anticipation of some turbulence from rotor off the hills. I was used to flying the Sting, with it’s much shorter and more rigid wings so I was not quite ready for what happened next.
As I came closer to Canberra, the rotor from the nearby hills increased dramatically and I was shocked as to how it was affecting me. At one stage I had over 1200’ per minute descent and I was getting thrown about like a cork on the sea. The ERSA and maps on the seat beside me became airborne and bounced off of the roof of the cockpit. The plane was surprisingly easy to fly, even in these harsh conditions and the large control surfaces made it responsive enough to penetrate through this extreme turbulence.
I lined up on approach to runway 30 and the tower began to call the wind for me as it was so variable. 230 15 kn, 280 25 kn, 320 12 kn, 310 28 kn – the wind was all over the place. I concentrated on keeping the plane straight and decided to land with one stage of flap and some extra speed. Although it was a challenge, the Virus handled the conditions well and I performed a nice landing without incident.
I certainly would not recommend that anyone fly in these conditions under normal circumstances, however this experience certainly gave me an increased confidence in what this little aircraft can do and the conditions in which it can operate safely.
Flight for Sight
My next big event was the ‘Flight for Sight’, a sponsored flight around Queensland raising money for the Royal Blind Foundation. My trip started with a leisurely flight from Canberra to the Gold Coast where we were to prepare the aircraft and attach all of the sponsorship signs. I had intended to take the more scenic coastal route but unfortunately the weather was against me and so I was forced to travel inland. I did this trip in a little over 5 hours with one stop for fuel at Armidale in case I had to divert due to weather. This again drove home how efficient these aircraft are on long journeys – I could have made the trip without refueling but, as the saying goes, the only time you have too much fuel is when you’re on fire.
The Flight for Sight took us from Brisbane across to Roma, up to Emerald, west again to Opalton, north to Mount Isa, east back to Cairns and then south along the coast back to Brisbane. Over 6000 kms, the trip was undertaken at a leisurely pace of 12 days.
The interesting aspect of this trip was that we experienced almost every imaginable flying condition, from rain and low clouds to blistering heat and strong winds. Surprisingly, the Virus handled all of the conditions well and we had no problems landing, even at Opalton where we had an estimated 30 knots crosswind and crowds of astounded onlookers who commented that not many aircraft would have landed in those conditions.
When we departed Opalton, we had massive sink and ordinary engine performance in the 40+ temperatures but we managed at least 400 fpm climb to drag ourselves back up into the cooler air at 9500 feet.
Along the coast, in the more dense air, I decided to see what performance I could get out of my new aircraft. With 4600 rpm set and a fuel flow of 11 liters per hour I was cruising at 110 knots IAS at 8500’. This was approximately 1 liter per hour more consumption than I had experienced on the trip from Canberra and the reduced efficiency was directly attributable to the fact that we had attached propeller tape to minimize prop damage on the outback strips we were visiting. I recall that the manufacturer, while visiting us at Narromine earlier in the year, had remarked that prop tape can reduce the efficiency of the propeller by up to 30%.
Noting this change in performance, I went low level and, flying straight and level at 500’ along the beach in the cool calm air of the morning, increased to 130 knots. I played with the variable pitch propeller and managed to get the consumption down to 13.8 liters per hour with around 4850 rpm at 130 knots IAS. Again, I expect this to be reduced without the prop tape but unfortunately I haven’t been able to try it again in nice smooth conditions.
Cooma Visits
A number of people have been calling me to organize a viewing and demonstration flight in the Virus. The guys down at Cooma have been some of the most persistent and, being so close to Canberra, I’ve taken the opportunity to visit a couple of times and take people for flights.
Peter Horsburgh has done some excellent work in publicizing the visits and organizing passengers for the flights. Unfortunately a couple of times he has organized full days and the weather has not been kind so we’ve had to cancel but I did manage to thank Peter by taking him for a quick flight over Cooma. We climbed out from Polo Flat to about 6500’ and I let Peter take the controls and get a feel for the plane. He thoroughly enjoyed the flying but was also keen to see how the Virus performed in the glide. We reduced to 60 knots, set the prop and switched off the engine. After feathering the prop, we were cruising at 59 knots and had a sink rate of 200 fpm. Peter mentioned the waves which come through Cooma off the hills to the west so we turned and thought that we could ‘ride the wave’. To our surprise, we hit a wave and began climbing at 400 fpm – not bad for two amateurs. We continued up to 8500’ where we decided to break away due to cloud. Peter then glided us back towards the airfield and, at about 1500’ AGL, we restarted the engine for approach.
Whenever I have had the opportunity to take passengers gliding, they have always been amazed at the performance of the Virus. It is definitely not a competition glider but it is certainly a lot of fun for those that want to try their hand at ridge soaring or simple thermalling. At 24:1, the Virus glides quite well but for those budding world champions, the Sinus’ glide ratio of around 30:1 is more for you.
When you finally fall out of the thermals and can’t get the height to return home, you simply restart the engine and climb, rather than performing a potentially dangerous outlanding as in most glider operations.
One definite advantage of flying in these aircraft is that they are inherently much safer than other planes in their category because of their glide capability. If an engine failure occurs at 2500’ AGL while cruising, you have around 10 minutes of glide time to relax, assess the situation, choose a landing spot and set yourself up for forced landing. The radius of landing spots available is also increased, with over 10 miles of glide range from 2500’ AGL.
General Handling and Comparisons
Most of my recent flying has been in the Sting and X-Air. The X-Air is obviously a vastly different aircraft so I won’t bother comparing the Virus to that but the Sting, although it’s in a slightly different class, is similar in price and performance.
The Sting is a very agile sports aircraft. With a VNE of 165 knots and a fast cruise of 130 knots, it attracts a lot of enthusiasts who travel long distances or want a fun aircraft that is responsive and sleek looking.
The Virus is a much more conventional looking aircraft, with high wings and conventional cabin. This however disguises the sleek nature of the plane. The manufacturer has taken every effort to minimize drag, by incorporating control horns within the wings, by concealing brake lines, enclosing the rescue parachute completely within the fuselage, etc. In addition, weight is kept to a minimum by using light weight alloys such as titanium for control horns and linkages. This amounts to a very fast aircraft under minimal power.
The Sting is fitted with a 100 hp Rotax 912 engine. The Virus is fitted with the 80 hp 912. This makes the Virus more economical in general operations and the reduced drag and weight only serve to improve this.
With its longer wings, the Virus is not quite as agile as the Sting but it has almost full length ailerons which compensate somewhat and increase the roll rate to a very respectable speed.
The flaperons are very effective and allow for four stages – negative, neutral, one stage and two. With such effective flaps, short take-offs and landings are easily achievable. The negative flap setting reduces drag in the cruise and it’s features like these that help to break the ‘1 knot per horsepower limitation’ that I have heard many a comment about.
Finally, the spoilers add a very effective and essential component to the flying of the Virus. Being such a low drag airframe, it is sometimes difficult to slow the aircraft down for landing. In addition, the aircraft will sit in ground effect for quite a long time. To counter this, the spoilers reduce the lift and allow easy landings in almost all conditions. By using the spoilers, rather than power on approach, landings become much safer. In the event of an engine failure, the approach is simply adjusted with the use of the spoilers to achieve a normal landing.
One advantage that the Virus does have over the Sting is the downward visibility. The Sting is quite good with its high cockpit but, as with all low wing aircraft, it has a ‘shadow zone’ in which you have no visibility below. The Virus, being high wing, does not have this limitation and it is possible to also slow the plane down and open the doors in flight for photographic trips. When turning, the wings do limit visibility in the direction of the turn but the manufacturer has compensated for this by installing a roof window which allows visibility with the aircraft above when thermalling with other gliders.
Use As a Training Aircraft
As a training platform, the Virus provides challenges that are not involved with most aircraft, but in some ways it is also easier to fly. With four stages of flap instead of three and with spoilers to aid in descent and landing, the Virus and Sinus aircraft may provide a challenge for newer pilots. However, the concepts which are learnt when flying the Virus are valuable in instilling safety in trainees. For instance, the glide approach used in these aircraft ensures that, in the event of an engine failure, the landing may still be performed safely. In many aircraft, the approach is shallow and power is required to ensure a successful landing. In the event of an engine failure, the student must select a point short of the field as the approach is too shallow to affect a glide approach.
The Virus can be landed easily in all configurations, both with and without flaps and/or spoilers, so it provides a good platform to stage training in all conditions. Given its high wing design and easy entry and exit, the aircraft is also able to sustain the onslaught of many trainees without the inherent damage to spats, wings steps, flaps, etc.
Finally, the full dual controls, including fully adjustable pedals and dual brakes, means that the instructor can be in full control of the aircraft without encroaching on the student’s controls. The only shared controls are flaps and spoilers.
Being able to glide, the Virus and Sinus are capable of providing training platforms for both powered and gliding operations.
Running Costs in Australian Dollars
For this comparison we have estimated a 5,000 hour airframe life and written off the aircraft in this period, realistically this could be more like 10,000 hours reducing the Hourly Cost to $11 per hour
Most ultralights are cheap to run and the Virus is no exception. The following table details the basic lifetime running costs for the Virus.
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Item
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Period of Cost (Hours)
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Overall Cost
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Hourly Cost
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Airframe
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5000
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$110,000
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$22
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Engine Servicing
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100
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$80
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$1
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Engine Overhall
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1500
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$8,000
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$5
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Fuel
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1
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$12
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$12
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Oil
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50
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$38
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$1
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Total Hourly Costs
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$41
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The above figures have been overestimated. For example, the normal oil change is at 100 hours but I sometimes run Avgas and therefore change my oil at every 50 hours. Engine servicing at every 100 hours primarily consists of replacing the spark plugs and oil filter but other components may need repair so I have allocated an average of $80. A full engine overhaul at 1500 hours ranges from $6000 to $8000 so I have included the higher amount in the calculations.
Most people would not keep an aircraft for the full 5000 hours so the actual airframe costs may differ however, this will depend on the resale value achieved and the tax benefits, if any, realized over the effective life of the aircraft. As a result, I have only calculated total life costs.
Overall, although the initial cost of purchasing a Virus may seem overwhelming, the actual hourly cost of flying this aircraft is still very cheap.
Summary
If you’re like me, you are skeptical of the performance figures published by manufacturers, especially for aircraft manufactured overseas since the flying conditions are generally quite different to those in Australia. In my six months and almost 100 hours experience in the Virus here in Australia, I have found the performance to equal or exceed the manufacturer’s specifications.
General leisurely cruise is 110 knots IAS at 8500’ (~121 knots TAS). Fast cruise can be maintained easily at 130 knots. Fuel usage is less than 11 lph in the cruise giving an endurance of 6 hours with half an hour reserve (based on actual fuel capacity rather than manufacturer specifications). Economy is drastically reduced, by at least ten percent, when propeller tape is used so this should be avoided unless absolutely necessary. Actual experience shows an increase of around 1 liter per hour when propeller tape is used.
The aircraft is easy to fly in all of the conditions experienced and would make a good training platform, both for gliding and powered training, although the Sinus would probably be the best option for the former.
Overall, this is an economical, stable and robust aircraft to fly. Pipistrel use this aircraft for their formation and aerobatic display team and they regularly prove its capabilities. The Virus certainly stacks up in my books as one of the leading aircraft available in Australia within this class.
Phil Allen Canberra Australia Phone 0417 040 052
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© X-Air Australia 2003 - 2009
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