F3F Rules

**** Please read carefully the local rules hereunder ****

5.8 CLASS F3F - RADIO CONTROL SLOPE SOARING (Effective 1st January 2018)

5. 8.1. Definition: This contest is a speed event for radio controlled slope gliders.

5.8.2. Characteristics of Radio Controlled Slope Gliders

Paragraph B.3.1 a) of Section 4B (Builder of the Model aircraft) is not applicable to class F3F.
  • Maximum surface area .................................... 150 dm2
  • Maximum flying mass . ...................................... 5 kg
  • Loading ............................................................ less than 75 g/dm2
The use of any onboard-sensed data to automatically move the control surfaces or to modify the
aircraft geometry is prohibited. 

Minimum radius of fuselage nose 7.5 mm in all orientations (see template below).

The radio shall be able to operate simultaneously with other equipment at the normally used spacing in the allocated R/C bands (i.e. 35 MHz : 10 kHz). The competitor may use three models in the contest. The competitor may combine the parts of the models between the rounds provided the resulting model used for flight conforms to the rules and that the parts have been checked before the start of the contest. Addition of ballast (which must be located internally in the model) and/or change of angles of setting are allowed. Variation of geometry or area is allowed only if it is actuated at distance by radio control.

Any technological device used to aid in supplying data of the air’s condition or direct feedback of the model’s flight status is prohibited during the flight. These devices include any transmission or receiving devices not used to directly control the model aircraft (telephones, walkie-talkies,  telemetry of airspeed and altitude etc), temperature detecting devices (thermal imaging cameras, thermometers etc), optical aids (such as binoculars, telescopes etc), and distance/altitude  measuring devices (GPS, laser range finders etc). Telemetry of signal strength at the aircraft receiver and state of the receiver battery is permitted. Use of corrective eyeglasses and sunglasses are permitted. If an infringement of this rule occurs, the pilot will be disqualified from the contest.

5.8.3. Competitor and Helpers: The competitor must operate his radio equipment personally. Each competitor is permitted one helper. The helper is only to assist and advise the competitor until the model is passing Base A for the first time and after the timed flight is completed.

5.8.4. Definition of an Attempt: There is an attempt when the model has left the hands of the competitor or his helper.

5.8.5. Number of Attempts: The competitor has one attempt on each flight. An attempt can be repeated if:

a) the launching attempt is impeded, hindered or aborted by circumstances beyond the control of the competitor, duly witnessed by the official judges;
b) his model collides with another model in flight or other impediment and the competitor is not
to blame on that account;
c) the flight was not judged by the fault of the judges.
d) the model (i.e. the fuselage nose) fails to pass above a horizontal plane, level with the
starting area, within five seconds of exiting the course, due to circumstances beyond the
control of the competitor, duly witnessed by the official judges.

The re-flight shall happen as soon as possible considering the local conditions and the radio frequencies. If possible, the model aircraft can stay airborne and has to be brought to launching height, launching speed and launching position before the new 30 second period is started by the judge.

5.8.6. Cancellation of a Flight: A flight is official when an attempt is carried out, whatever result is

A flight is official but gets a zero score if:

a) the competitor used a model not conforming to FAI rules;
b) the model loses any part while airborne;
c) the helper advises the competitor during the timed flight;
d) the model is controlled by anyone other than the competitor;
e) the flight is not carried through;
f) the model lands outside the assigned landing area;
g) the model is not launched within 30 seconds from the moment the starting order is given.
h) any part of the model aircraft fails to pass above a horizontal plane, level with the starting area, within five seconds of exiting the course.
i) the model aircraft is not seen entering the course by the Judge at Base A.

5.8.7. Organisation of Starts: The flights are to be performed round by round. The starting order is
settled by draw in accordance with the radio frequencies used. The competitor is entitled to three (3) minutes of preparation time from the moment he is called to the ready box. After the three (3) minutes have elapsed, the starter may give the order to start. After the starter has given the order to start, the competitor or his helper must launch the model within thirty (30) seconds by hand from the starting area indicated by the organiser. If possible, the starting area, including the audio system, shall be situated in the middle of the course (equal distance from Base A and Base B). The time from launch to the moment the model enters the speed course must not exceed thirty (30) seconds.
If the model has not entered the speed course (i.e. first crossing of Base A in the direction of Base
B) within the thirty (30) seconds, the flight time will commence the moment the thirty (30) seconds
expire. If the model has not entered the speed course within the thirty (30) seconds, this is to be
announced by the judges.

5.8.8. Task: The task is to fly ten (10) legs on a closed speed course of one hundred (100) metres in the shortest possible time from the moment the model first crosses Base A in the direction of Base B. If some irremovable obstacles do not allow one hundred (100) metres the course may be shorter but
not less than eighty (80) metres. This exception does not apply for world or continental championships. The competitor’s model aircraft must be visible to the appropriate judge on the turns at Bases A
and B.

5.8.9. The Speed Course: The speed course is laid out along the edge of the slope and is marked at
both ends with two (2) clearly visible flags. The organiser must ensure that the two (2) turning
planes are mutually parallel and perpendicular to the slope. Depending on the circumstances, the two (2) planes are marked respectively Base A and Base B. Base A is the official starting plane. At Base A and Base B, an Official announces the passing of the model (i.e. any part of the model aircraft) with a sound signal when the model is flying out of the speed course. Furthermore, in the case of Base A, a signal announces the first time the model is crossing Base A in the direction of Base B.

5.8.10. Safety: The sighting device used for judging the turns must be placed in a safe position. The organiser must clearly mark a safety line representing a vertical plane which separates the speed course from the area where judges, other officials, competitors and spectators stay. Crossing the safety line by any part of the model aircraft during the measured flight will be penalised by 100 points subtracted from the sum after conversion, the penalty not being discarded with the result of the round. The organiser must appoint one judge to observe, using an optical sighting device, any crossing of the safety line.

5.8.11. Judging: The flights are judged by two judges who do not have to be the same for all competitors. The judges' task is to control that the flights are performed according to the rules, to be time keepers and to ensure that the right distance is flown.

5.8.12. Scoring: The result of the flight is stated as the time in seconds and hundredths of seconds
obtained by each competitor. For the purpose of calculating the result of the round or group (see
paragraph 5.8.16), the competitor's result is converted this way:

1000 * ( Pw / P )

where Pw is the best result in the round or group (see paragraph 5.8.16) and P is the competitor’s

5.8.13. Classification: A minimum of four (4) rounds must be flown for the competition to be valid. In this case the lowest round score of each competitor will be discarded. If more than fourteen rounds
were flown, the two lowest round scores will be discarded. The remaining results are added to obtain the final score which will determine the position of the pilot in the final classification. To avoid ties in the classification concerning the five best scores, "classification rounds" are flown until the ties are broken. If this is not possible, the result of the discarded round will determine each competitor's position in the final classification.

5.8.14. Team Classification: To establish the ranking for international team classification, add the final individual scores of three best members of the team. Teams are ranked according to the highest
numerical score to lowest. In the case of a national team tie, the team with the lower sum of place numbers, given in order from the top, wins. If still equal, the best individual placing decides. 

5.8.15. Organisation of the Contest: The competition must be held at a site which is suitable for slope soaring. When marking the starting and landing areas and the turning planes, the organiser must take into account the configuration of the terrain and the wind direction.

5.8.16. Changes: Any changes of the flight and landing areas may be made only between rounds or
between groups.

5.8.17. Weather Conditions and interruptions: A round in progress must be interrupted if:

a) the wind speed is below three (3) m/sec or more than twenty five (25) m/sec for at least twenty (20) seconds two (2) metres above the ground at the flight-line.
b) the direction of the wind constantly deviates more than 45O from a line perpendicular to the main direction of the speed course.
c) In the case of rain.

If these conditions arise during the flight the contest director must interrupt the contest and the competitor is entitled to a re-flight.

The whole group must be divided into groups of equal size (+-one (1) competitor) with a minimum
number of competitors in one group of ten (10) before the round starts.

If the weather is stable during the whole round only one group is evaluated; if the competition must be interrupted more than thirty (30) minutes, then the interrupted group must start from the beginning and the results are evaluated for each group (see paragraph 5.8.12).

5.8.18 Site: The diagram of recommended F3F Flying Field Layout follows.