The Fédération Aéronautique Internationale or FAI, is also known as "The World Air Sports Federation" .
Since F5J is an FIA competition class, they make the official rules.
It would be a good idea to get to know the F5J rules. These can be downloaded from the FIA web site or from the Gliderscore site.
29 September 2012
25 September 2012
F5J is a model glider competition class, proposed by the International Federation of Aeronautics or FAI.
It is a thermal duration competition where the gliders are launched by means of an electric motor.
Traditional thermal duration requires the glider to be towed to flying altitude by means of a 2 man tow team using a 150m line and pulley system. The problem with this method, (still used in competition) is that you require 2 willing helpers before enjoying a quick flight. This led to the use of an electric winch that allowed pilots to fly on their own. Electric winches are expensive and heavy to cart around. It was not long before someone popped an electric motor and a few NiCad batteries into a glider to enable easy launching.
Recent developments resulted in the availability of inexpensive and powerful electric motors and batteries. Electric thermal duration has become very affordable and has taken the model gliding world by storm. At first complex rules were used to penalize gliders with powerful brush-less motors in order to allow the brushed motors to compete. During the course of 2010 and 2011, a new set of rues were discussed and provisionally approved by FAI. In the new rules, any combination of airframe, motor or battery may be used as long as the following general specifications are not exceeded:
Launch altitude is penalized by 0.5 points per meter up to 200m. For altitudes higher than 200m the penalty is increased 3 points per meter. Motor run time is limited to 30 seconds. Zooming in order to gain more altitude after the motor cut point is dissuaded by the fact that the ALD logs the highest altitude during the period of 10 seconds after the motor was cut, either by the pilot or the ALD. This means that anyone can compete as long as the glider can reach a reasonable altitude within 30 seconds, and stay aloft for the required working time of 10 minutes.
Up to R2000.00
I do not think that it would be possible to fly for much less than about R2000.00. Someone may prove me wrong but consider the cost of the limiting device at about R680.00 and you are nearly halfway there. On a budget you can haul out the 20 year old Gentle Lady and add a Park 450 – Park 480 size motor and you can be competitive. Many pilots are also dedicated scratch-builders and it might be an option if you have the time and patience.
Between R2000.00 and R3500.00
This would be an acceptable budget for beginners and experienced pilots that would just like to dip their toes into the F5J waters. There are a few very well designed ARF foamies for example, the Parkzone Radian-Pro or Multiplex Cularis. Both of these foamies have 4 servo wings. You may also be able to get a glass moulded kit that can be fitted with the necessary hardware. The very successful 2m Tsotsi comes to mind.
The Tsotsi is still produced by Evan Shaw and Piet Rheeders.
More than R3500.00
Most of the major competition sailplane manufacturers produce an “E” version of their F3J or F3B models. Some of the “E” models from the likes of Vladimir or NAN will set you back $1600.00 or more, and that is without any electric components. These planes however are suitable for world class competition.
In conclusion, a wide variety of sailplanes will do very well. Early F3J (soaring duration) models have enough fuselage space to accommodate the motor and electronics and LiPo batteries.
It is a thermal duration competition where the gliders are launched by means of an electric motor.
Traditional thermal duration requires the glider to be towed to flying altitude by means of a 2 man tow team using a 150m line and pulley system. The problem with this method, (still used in competition) is that you require 2 willing helpers before enjoying a quick flight. This led to the use of an electric winch that allowed pilots to fly on their own. Electric winches are expensive and heavy to cart around. It was not long before someone popped an electric motor and a few NiCad batteries into a glider to enable easy launching.
Recent developments resulted in the availability of inexpensive and powerful electric motors and batteries. Electric thermal duration has become very affordable and has taken the model gliding world by storm. At first complex rules were used to penalize gliders with powerful brush-less motors in order to allow the brushed motors to compete. During the course of 2010 and 2011, a new set of rues were discussed and provisionally approved by FAI. In the new rules, any combination of airframe, motor or battery may be used as long as the following general specifications are not exceeded:
- Mass not greater than 5kg
- Wing span no greater than 4m
- Wing area no greater than 150dm²
Launch altitude is penalized by 0.5 points per meter up to 200m. For altitudes higher than 200m the penalty is increased 3 points per meter. Motor run time is limited to 30 seconds. Zooming in order to gain more altitude after the motor cut point is dissuaded by the fact that the ALD logs the highest altitude during the period of 10 seconds after the motor was cut, either by the pilot or the ALD. This means that anyone can compete as long as the glider can reach a reasonable altitude within 30 seconds, and stay aloft for the required working time of 10 minutes.
Choice of F5J gliders
Interested F5J pilots may wonder what glider to use. The choice would depend on your budget.Up to R2000.00
I do not think that it would be possible to fly for much less than about R2000.00. Someone may prove me wrong but consider the cost of the limiting device at about R680.00 and you are nearly halfway there. On a budget you can haul out the 20 year old Gentle Lady and add a Park 450 – Park 480 size motor and you can be competitive. Many pilots are also dedicated scratch-builders and it might be an option if you have the time and patience.
Between R2000.00 and R3500.00
This would be an acceptable budget for beginners and experienced pilots that would just like to dip their toes into the F5J waters. There are a few very well designed ARF foamies for example, the Parkzone Radian-Pro or Multiplex Cularis. Both of these foamies have 4 servo wings. You may also be able to get a glass moulded kit that can be fitted with the necessary hardware. The very successful 2m Tsotsi comes to mind.
More than R3500.00
Most of the major competition sailplane manufacturers produce an “E” version of their F3J or F3B models. Some of the “E” models from the likes of Vladimir or NAN will set you back $1600.00 or more, and that is without any electric components. These planes however are suitable for world class competition.
In conclusion, a wide variety of sailplanes will do very well. Early F3J (soaring duration) models have enough fuselage space to accommodate the motor and electronics and LiPo batteries.
Subscribe to:
Posts (Atom)