PART FIVE - TECHNICAL RULES FOR RADIO CONTROLLED
MODEL CONTESTS
5.4. CLASS F3C HELICOPTERS
5.4.1. DEFINITION OF A RADIO CONTROLLED (R/C) HELICOPTER
An R/C helicopter is a heavier-than-air aeromodel that derives all of its lift and horizontal propulsion from a power driven rotor system(s) rotating about a nominally vertical axis (or axes). Fixed horizontal supporting surfaces up to 4 percent of the swept area of the lifting rotor(s) are permitted. A fixed or controllable horizontal stabilizer of up to 2% of the swept area of the lifting rotor(s) is permitted. Ground effect machines (hovercraft), convertiplanes or aircraft that hover by means of propeller slipstream(s) deflected downward are not considered to be helicopters.
5.4.2. BUILDER OF THE MODEL
Paragraph B.3.1 of Section 4b (Builder of the model) is not applicable to class F3C.
5.4.3. GENERAL CHARACTERISTICS
AREA: The swept area of the lifting rotor cannot exceed 300 dm2. For helicopters with multiple rotors whose rotor shafts are more than one rotor diameter apart the total swept area of both rotors cannot exceed 300 dm2. For helicopters with multiple rotors whose rotor shafts are less than one rotor diameter apart the swept area of both rotors (counting the area of superposition only once) cannot exceed 300 dm2.
a) WEIGHT: The weight of the model (without fuel) must not exceed 6 kg.
b) MOTOR: Maximum piston engine displacement : 10 cm3 two cycle,
20 cm3 four cycle,
25 cm3 gasoline only.
Electric motors are limited to a maximum no load voltage of 42 volts for the propulsion circuit and one battery change after the hovering manoeuvres.
c) GYROS: An electronic rate gyro is permitted on the yaw axis only.
d) ROTOR BLADES: All-metal main or tail rotor blades are prohibited.
5.4.4 NOISE LIMIT
Noise level measurements must be made before the start of a competition, preferably during the official practice day. The noise level must be measured at a distance of 3 metres while the helicopter is hovering at eye level over the center of a 2 metre diameter circle. During the measurement the helicopter must be rotated through 360 degrees to determine the maximum noise level. The sound pressure level must not exceed 90 dB(A) over a soft (grass) surface and 92 dB(A) over a hard (asphalt, concrete, etc.) surface. If the noise level limit is exceeded during the first measurement, two additional measurements must be made to substantiate the excessive noise level. The competitor may modify the helicopter and/or silencer system to reduce the noise level and after verification of an acceptable level, will be permitted to fly. If the noise level cannot be reduced to or below the noise level limit it will not be allowed to fly in the competition. The measuring equipment must be calibrated to the dB(A) sound pressure level scale defined in applicable ISO Standards. If the noise measurement criteria cannot be met, the measurements will be advisory only and no competitor can be excluded from the competition.
5.4.5. CONTEST AREA LAYOUT
See FIGURE 5.4.A..
5.4.6. NUMBER OF HELPERS
Each competitor is allowed only one mechanic/caller. The mechanic/caller must announce the start, finish and name of each manoeuvre, and may inform the pilot of wind direction, remaining flight time, proximity to prohibited areas and intrusions into the flight area. The mechanic/caller must not act as a coach. Team managers may observe the flight from a position 5 metres behind the judges and away from the start box. Team managers may serve as mechanic/caller if no separate person is available for this task.
5.4.7. NUMBER OF MODELS
The number of models eligible for entry is two (2). Models 1 and 2 may only be exchanged within the start box.
5.4.8. NUMBER OF FLIGHTS
At Continental and World Championships, each competitor is entitled to four (4) official preliminary flights. After completion of the preliminary flights the top 10 placing or 20 percent (whichever is greater) of the competitors are entitled to three fly-off flights. At national and open International Competitions the preliminary/fly-off system is not mandatory.
5.4.9. DEFINITION OF AN OFFICIAL FLIGHT
There is an official flight when the competitor is officially called. The flight may be repeated at the Contest Director's discretion when for any unforeseen reason, outside the control of the competitor, the model fails to make a start such as:
a) The flight cannot safely be made within the allowed time limit.
b) The competitor can prove that the flight was hindered by outside interference.
c) Judging was impossible for reasons beyond the control of the competitor (model, engine, or radio failures are not considered to be outside the control of the competitor). In such cases the flight may be repeated immediately after the attempt, during the same round or at the end of the round, at the discretion of the Contest Director.
5.4.10. SCORING
Each manoeuvre is given a score between 0 and 10 (including half) points by each judge. A new score sheet is issued to each competitor for each round. Only the competitor's number (no name or nationality) will appear on the score sheet. Any manoeuvre not completed shall be scored zero (0) points. There shall be an official located on the field where any flight over the prohibited area can be observed. The prohibited area is the shaded area in Figure 5.4.A behind the judges line. The area extends to infinity to the left, right and rear. A visual or audible signal shall be given to indicate such overflights. Competitors overflying this area will be penalised by scoring zero (0) points for the current flight. However, the judges shall score all manoeuvres. If an infringement has been made, the scores will be deleted from all score sheets after the flight. In addition, there shall be no score when:
a) The competitor flies a model that has been flown in the same competition by another competitor, or flies a model that does not comply with the definition and general characteristics of a radio controlled helicopter.
b) The competitor does not deliver his transmitter to the impound or operates his transmitter during a round without permission.
c) The competitor starts his model outside of the start box.
d) The competitor gets his transmitter from the impound before he is officially called.
5.4.11. CLASSIFICATION
After the completion of four official (preliminary) rounds, the best three scores will be used to determine the team standings. The top 10 or 20 percent (whichever is greater) of all competitors (rounded up in case of an odd number) then compete in three fly-off rounds to determine the final individual classification. The results of the best three preliminary rounds (normalised to 1000 points) will count as one score. This score, plus the three fly-off scores provide four scores with the best three to count for the final individual classification. The fly-offs to determine the individual classification are only required for Continental and World Championships. If the competition is interrupted during the preliminary rounds, the final team classification will be determined by counting all completed preliminary rounds and dropping the lowest. If the competition is interrupted during the fly-off rounds, the final individual classification will be determined by counting all completed fly-off rounds plus the results from the preliminary rounds. All scores for each round will be normalised by awarding 1000 points to the highest scoring flight. The remaining scores are then normalised to a percentage of the 1000 points in the ratio of actual score over the score of the winner of the round. If only one round is possible then the classification will be based on that one round.
For example:
Score(X)
Points(X) = ---------------- X 1000
Score(W)
Where Points (X) = Points awarded to competitor X
Score(X) = Score of competitor X
Score(W) = Score of winner of the round
Ties for any of the first three places will be broken by counting the highest throwaway score. If the tie still stands a "sudden death" fly-off must take place within one hour.
5.4.12. JUDGING
At Continental and World Championships the organiser must appoint a panel of five judges for each round. The final score of each flight is obtained by deleting the highest and lowest scores for each manoeuvre from the five judges. At open or other International Competitions the number of judges may be reduced to a minimum of three with no throwaway scores.
There shall be training flights for judges with a debriefing session immediately before a Continental or World Championships.
The scoring system must be organised in such a way that the competitors and the spectators can clearly see the scores awarded by all judges after each flight. The score sheet notation must be written by the judges themselves.
5.4.13. ORGANISATION
TRANSMITTER & FREQUENCY CONTROL (See Section 4b, Paragraph B.8)
FLIGHT ORDER
The flight order for the first preliminary round will be determined by a random draw, taking into account that frequency will not follow frequency and team member will not follow team member of the same team. The flight order for rounds two, three and four will start at the first, second and third quarter of the initial order. The flight order for each fly-off round will be established by a separate random draw.
PREPARATION TIME
A competitor must be called at least 5 minutes before he is required to enter the start box. A start box 2 metres in diameter will be provided away from the flight line, spectators, competitors and models (see FIGURE 5.4.A). When the previous competitor’s flight time reaches 6 minutes the flight line director gives the signal to start the engine. The competitor is given 5 minutes to start the engine and make last minute adjustments. The model may only be hovered in the start box up to eye level and must not be rotated beyond 180 degrees left or right relative to the competitor. If the model is rotated beyond 180 degrees the flight is terminated. The competitor in the start box must reduce his engine's speed to an idle when the preceding competitor has completed the "STALL WITH PULLBACK RECOVERY" manoeuvre. If the competitor is not ready after the 5 minute preparation time, he is allowed to complete his adjustments in the start box; however, his flight time will have started at the end of the 5 minute interval.
FLIGHT TIME
The flight time of 9 or 10 minutes begins when the competitor leaves the start box with the permission of the flight line director and the judges. If the allotted time expires before the schedule is completed, the remaining manoeuvre(s) will be scored zero and the competitor is required to land his model as soon as possible.
RESTRICTIONS
The competitor must fly his model directly to (and land on) the central helipad after he leaves the start box. The model must be flown with the skids or landing gear at eye level without practicing manoeuvres (no rotations beyond 180 degrees relative to the competitor). After the competitor has left the start box he is not allowed to touch the model, and if the motor stops, the flight is terminated. For the case of electric motors the competitor (or his caller) is allowed to change the battery once after the hovering manoeuvres without making any adjustments to the model and the flight time clock will be stopped for a maximum of 2 minutes.
5.4.14. MANOEUVRE SCHEDULES
FLIGHT PROGRAM
The flight program consists of Manoeuvre Schedule A consisting of nine (9) manoeuvres and Manoeuvre Schedule B consisting of ten (10) manoeuvres (see ANNEX 5D - F3C MANOEUVRE DESCRIPTIONS). The manoeuvre schedules are listed below with the starting and ending direction (U, U = Upwind, Upwind; D, D = Downwind, Downwind; D, U = Downwind, Upwind) of each aerobatic manoeuvre, relative to the wind, as indicated. The k-factors for the hovering manoeuvres (1, 2 and 3) in each schedule are equal to two (2) and for the remaining manoeuvres the k-factors are one (1). The competitor has 9 minutes to complete Schedule A and 10 minutes to complete Schedule B. Schedule A will be flown for the preliminary rounds 1 through 4. Fly-off rounds 1, 2 and 3 will use Schedule B.
Schedule A
Vertical Triangle with 360 degree Pirouette
NOSE-IN AND TAIL-IN HORIZONTAL EIGHT
VERTICAL RECTANGLE 1
Two Consecutive INSIDE Loops - U, U
Two Consecutive Axial Rolls - D, D
ROLLING STALL TURN - U, U
inside Loop with half Rolls - D, D
STALL WITH PULLBACK RECOVERY - U, U
Autorotation with 180 degree turn - D, U
Schedule B
VERTICAL TRIANGLE WITH 180 AND 360 DEGREE PIROUETTES
CIRCLE WITH 360 DEGREE PIROUETTES
VERTICAL RECTANGLE 2
ROLL REVERSAL - D, D
PUSHOVER WITH 360 DEGREE PIROUETTE - U, U
Cobra Roll with opposite half rolls - D, D
540 DEGREE STALL TURN WITH HALF ROLL - U, U
CUBAN EIGHT - D, D
STaLL WITH PULLBACK RECOVERY - U, U
AUTOROTATION WITH 180 DEGREE TURN - D, U
PERFORMANCE OF THE SCHEDULES
The competitor must stand in the 1.2 metre circle ( labelled P in Figure 5.4.A - F3C Contest Area Layout ) located 4,0 metres from the 10 metre square and in front of the centre judge. Before the start of the first manoeuvre the competitor must land the model on the central helipad. The model may face left or right but must be parallel with the judges’ line. Before the start of the first manoeuvre the model may be repositioned
(rotated 180 degrees) only once. The manoeuvres must be executed as described with landings performed only where listed. If the model is repositioned between manoeuvres the next manoeuvre will receive a zero score.
After completing the hovering manoeuvres the competitor is allowed one free pass to set up for the aerobatic sequence. All aerobatic manoeuvres must be performed in an airspace that will allow them to be clearly seen by the judges. This airspace is defined by a field of view up to 60 degrees above the horizon and between lines 60 degrees to the right and left of judges 1 and 5. The non-observance of this rule will be penalised by a loss of points. The aerobatic manoeuvres must be performed in a smooth flowing sequence, with a manoeuvre performed on each pass before the judges. There are no restrictions on turnaround manoeuvres. The competitor must execute each listed manoeuvre only once during a flight. The name (number) and start and finish of each manoeuvre must be announced by the competitor or his caller. A manoeuvre performed out of sequence will result in a zero score for that manoeuvre and all remaining manoeuvres. Before the autorotation manoeuvre the competitor is allowed another free pass to accommodate a possible change in wind direction.
5.4.15. MANOEUVRE DESCRIPTIONS
5.4.16. JUDGES' GUIDE
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F3C MANOEUVRE DESCRIPTIONS
5D.1 GENERAL
The manoeuvres are displayed in pictorial form in Figures 5D1 and 5D2 for the case where the wind direction is left to right. The following descriptions apply to all manoeuvres and if not executed properly must result in downgrades. If a manoeuvre is unrecognisable the score shall be zero (0) points. Ascents from, and descents to, the central helipad must be vertical. Landings must be smooth and centred on the helipad. During the hovering manoeuvres all stops must be of 2 seconds minimum duration. Circular and linear hovering segments must be executed at a constant speed. Pirouettes must be performed at a constant turning rate. The hovering manoeuvres must be started with the nose of the model facing left or right and must be flown as a unit (the starting heading must be same for each hovering manoeuvre). The competitor must stand in the 1,2 meter diameter circle marked "P" in Figure 5.4.A during all manoeuvres All aerobatic manoeuvres must start and end in the direction indicated with a straight and level flight line of 10 metre minimum length. Entry and exit must be at the same altitude and heading. Loops or parts of a loop must be round and have the same diameter. Consecutive loops must be in the same location and plane. Rolls must be executed at a constant roll rate. Consecutive rolls must have the same roll rate and must be at the same altitude and heading. During all aerobatic manoeuvres the competitor must maintain his model above a minimum altitude of 10 metres. Aerobatic manoeuvres must be centred within the 120 degree horizontal field of view. Aerobatic manoeuvres flown at a distance greater than 100 metres from the judges line will be downgraded. In case of a dispute the following text takes precedence over Figures 5D1 and 5D2.
5D.2 SCHEDULE A (click link to jump to graphic)
A1. VERTICAL TRIANGLE WITH 360 DEGREE PIROUETTE
Model takes off from central helipad and climbs vertically to eye level and stops. Model then flies backwards from central helipad to one of the center flags (2 or 5) and stops. Model then climbs forward at 45 degrees to an altitude 5 m above eye level directly over central helipad and stops. Model performs a 360 degree pirouette in either direction and stops. Model then descends forward at 45 degrees to eye level directly over opposite center flag and stops. Model then flies backwards to central helipad, stops and descends to a landing on the central helipad.
Points will be subtracted for the following reasons:
Ascent and/or descent was not at 45 degrees.
Model did not maintain lateral position during pirouette.
A2. NOSE-IN AND TAIL-IN HORIZONTAL EIGHT
Model takes off from helipad and ascends vertically to eye level and stops. Model then flies a nose-in circle in either direction for the first half of the eight followed by a tail-in circle in the opposite direction for the second half of the eight. The manoeuvre must be executed parallel to the judges’ line and the circles must be centred on the center flags (2 and 5). Model returns to a point directly over the central helipad and stops. Model then descends to a landing on the helipad.
Points will be subtracted for the following reasons:
Radii of the circles were not the same.
Nose or tail of model did not always point to center of circle.
A3. VERTICAL RECTANGLE 1
Model takes off from helipad and ascends vertically to eye level and stops. Model then flies backwards to one of the center flags (2 or 5) and stops. Model then climbs vertically 4 m while simultaneously performing a slow 360 degree pirouette in either direction and stops. Model then flies forward 10 m to opposite center flag and stops. Model then descends 2 m, stops, performs a 360 degree pirouette at that altitude in opposite direction tothe first pirouette and stops again. Model then descends another 2 m back to eye level and stops. Model flies backwards to central helipad and stops. Model then descends to a landing on central helipad.
Points will be subtracted for the following reasons:
Lateral position changed during 360 degree pirouette.
Pirouettes were not exactly 360 degrees.
Pirouettes were not centred over the flags.
Model did not land smoothly on helipad.
Pirouettes were same direction (zero score).
A4. TWO CONSECUTIVE INSIDE LOOPS - UPWIND/UPWIND
Model flies straight and level for a minimum of 10 m, then enters first loop. Second loop immediately follows first loop and must be in same location and plane (superimposed).
Points will be subtracted for the following reasons:
Model hesitated between loops.
A5. TWO CONSECUTIVE AXIAL ROLLS - DOWNWIND/DOWNWIND
Model flies straight and level for a minimum of 10 m. Model executes two (2) consecutive rolls while maintaining longitudinal axis in the direction of flight. Rolls may be executed in either direction. The total duration must be a minimum of 4 seconds. Model must be in upright attitude when it crosses the centreline (CL in Figure 5.4.A).
Points will be subtracted for the following reasons:
Model hesitated between rolls.
A6. ROLLING STALL TURN - UPWIND/UPWIND
Model flies straight and level for a minimum of 10 m, then transitions to a vertical ascent at 90 degrees immediately followed by a half roll in either direction and vertical ascent of one fuselage length minimum. When the vertical ascent ends, model executes a 180 degree pirouette so that the nose points downward. After diving, the model transitions back to same altitude and heading as at beginning of manoeuvre.
Points will be subtracted for the following reasons:
Model did not climb vertically.
Model drifted toward or away from the judges.
Pirouette was not exactly 180 degrees.
Half roll was not exactly 180 degrees.
A7. INSIDE LOOP WITH HALF ROLLS - DOWNWIND/DOWNWIND
Model flies straight and level for a minimum of 10 m, executes a half roll to inverted position followed by a recognisable straight segment, followed by a downward inside loop. Immediately after the completion of the inside loop model flies a recognisable straight segment followed by a second half roll back to the upright position. Manoeuvre is completed by flying straight and level for 10 m minimum. Half rolls may be executed in either direction.
Points will be subtracted for the following reasons:
Model drifted toward or away from the judges.
Half rolls were not exactly 180 degrees.
A8. STALL WITH PULLBACK RECOVERY - UPWIND/UPWIND
Model flies straight and level for 10 m and enters the manoeuvre by pulling up into a vertical ascent after passing the center line (CL). After the model comes to a complete stop the model transitions to fast backward
flight at constant altitude and must be in level flight when it crosses the center line. Model continues to a point that is at the same altitude and the same distance from the centreline but in the opposite direction and comes to a stop with nose pointing down. The model then continues by descending a path that mirrors the entry path. After the descent, model transitions to same heading and altitude as at the start of the manoeuvre. Model continues for 10 m to finish manoeuvre.
Points will be subtracted for the following reasons:
Ascending and descending segments were not parallel.
Model did not come to a complete stop.
A9. AUTOROTATION WITH 180 DEGREE TURN - DOWNWIND/UPWIND
Model flies at a minimum altitude of 20 m. Manoeuvre begins when model crosses an imaginary plane that extends vertically upward from a line drawn from the center judge out through the central helipad. Model must be in the autorotative state when it cuts this plane, the engine must be off at this point and the model must be descending. The 180 degree turn must start at this point and the turning and descending rate must be constant from this point to a point just before touchdown on the helipad. The flight path of the model must appear as a semi-circle when viewed from above, starting at the vertical plane and ending at a line drawn from the center judge through the central helipad. The model's flight path must never be parallel to the ground or judge's line.
Scoring criteria:
The maximum score of 10 points can only be achieved when the model makes a smooth touchdown on the central helipad with the skids or landing gear completely inside the 1,2 m circle and parallel to the judge's line. A maximum score of 9 points can be obtained with a perfect landing inside the 1,2 m circle but with part of the landing gear touching the circle (rotor shaft must point to inside of circle when viewed from above). If the model makes a perfect landing inside the 10 m square the manoeuvre can achieve a maximum score of 8 points. If the model makes a perfect landing outside the 10 m square a maximum score of 5 points can be awarded. If the flight path is stretched (flying parallel to the ground and/or judge's line) to reach the square, line or helipad, the manoeuvre will be severely downgraded. If the 180 degree turn is completed outside the 10 m square the maximum score can only be 5 points.
Points will be subtracted for the following reasons:
Model made a hard landing.
Model landed while it still had forward speed.
Model did not perform an exact 180 degree turn.
Model did not maintain a constant rate of descent during 180 degree turn.
Model did not maintain a constant turning rate during 180 degree turn.
Flight path was stretched to reach helipad or square.
If engine was still running during manoeuvre, score will be zero.
5D.3 SCHEDULE B (click link to jump to graphic)
B1. VERTICAL TRIANGLE WITH 180 AND 360 DEGREE PIROUETTES
Model takes off vertically from central helipad to eye level and stops. Model then flies backwards from central helipad to one of the center flags (2 or 5) and stops. Model then performs a 180 degree tail rotor turn in either direction and stops. Model then climbs backwards at 45 degrees to a point 5 m above eye level and directly over central helipad and stops. Model performs a 360 degree pirouette in either direction and stops again. Model then descends backwards at 45 degrees to eye level directly over the opposite center flag and stops. Model performs a 180 degree tail rotor turn in opposite direction to the first 180 degree turn and stops. Model then flies backwards to central helipad, stops and descends to a landing on the central helipad.
Points will be subtracted for the following reasons:
Ascent and/or descent was not at 45 degrees.
Model rotated during ascent and/or descent.
Model did not maintain lateral position during pirouettes.
180 degree pirouettes were in same direction (score = zero)
B2. CIRCLE WITH 360 DEGREE PIROUETTES
Model takes off vertically from central helipad and stops at eye level. Model then flies backwards to one of the center flags (2 or 5) and stops. Model then flies a circle in either direction while simultaneously rotating twice (relative to the center of the circle) about its yaw axis. The two pirouettes must be executed in the same direction as the circular path and at a constant rate (for a clockwise circle viewed from above, the pirouette must be executed in clockwise direction). Model comes to a stop at 360 degree point. Model flies forward to a point directly over the helipad. Model descends vertically to a landing on the helipad.
Points will be subtracted for the following reasons:
Circle was not round.
Nose and tail were not pointing to center of the circle at appropriate points.
Model failed to fly over square boundary.
Pirouettes in opposite direction (score = zero)
B3. VERTICAL RECTANGLE 2
Model takes off from helipad and ascends vertically to eye level and stops. Model flies backward to outer flag (2 or 5) and stops. Model climbs 4 m above eye level while simultaneously performing a slow 360 degree pirouette in either direction and stops. Model then flies forward 10 m to opposite center flag and stops. Model then descends 4 m to eye level while simultaneously performing a 360 degree pirouette in opposite direction of first pirouette and stops again. Model then flies backwards toward central helipad and stops. Model then descends to a smooth landing on the central helipad.
Points will be subtracted for the following reasons:
Model did not ascend or descend in a straight line in vertical segments.
Model changed lateral position during 360 degree pirouettes.
Pirouettes were not 360 degrees.
Pirouettes were not centred over the flags.
Pirouettes were of same direction (score = zero).
B4. Roll REVERSAL - Downwind/DOWNWIND
Model flies straight and level for a minimum of 10 m. Model executes a roll in either direction followed by a recognisable straight segment, followed by a roll in the opposite direction while maintaining longitudinal axis in the direction of flight. Second roll must be executed at same roll rate. The total duration of the two rolls must be four (4) seconds minimum.
Points will be subtracted for the following reasons:
Duration of manoeuvre was less than 4 seconds.
Upright attitude between rolls was not centred in front of judges.
B5. Pushover WITH 360 DEGREE Pirouette - UPWIND/UPWIND
Model flies straight and level for 10 m minimum and then enters a 90 degree vertical ascent. When model comes to a stop, nose of model is pushed forward 90 degrees to level and upright position and stops. Model then executes a 360 degree pirouette in either direction and stops. This is followed by nose of model pushed over 90 degrees again to vertical (nose down) position followed by vertical descent and 90 degree pullout back to the same altitude and heading as at start of the manoeuvre. Manoeuvre is completed by flying straight and level for 10 m minimum.
Points will be subtracted for the following reasons:
Vertical segments were not parallel.
Model drifted toward or away from the judges.
Pirouette was not 360 degrees.
Pushovers were not 90 degrees.
B6. COBRA ROLL WITH HALF ROLLS - DOWNWIND/DOWNWIND
Model flies straight and level for 10 m and enters the manoeuvre by pulling up into a 45 degree climb. After a 5 m minimum straight segment the model performs a half roll in either direction to the inverted position and continues to climb at 45 degrees for 5 m minimum. At this point the model enters a 45 degree dive and after a 5 m minimum straight segment performs another half roll in either direction. Model continues for 5 m minimum and then recovers at starting altitude in level flight for 10 m to finish manoeuvre.
Points will be subtracted for the following reasons:
Ascending and/or descending segments were not at 45 degrees.
Straight segments before and after half rolls were not recognisable.
B7. 540 DEGREE Stall Turn WITH HALF Roll - UPWIND/UPWIND
Model flies straight and level for a minimum of 10 m, then transitions to a vertical ascent. After the model comes to a stop, model executes a 540 degree pirouette, so that the nose points downward. While descending, model executes a half roll in either direction and transitions back to same altitude and heading as at beginning of manoeuvre.
Points will be subtracted for the following reasons:
Model did not ascend vertically.
Model drifted toward or away from the judges.
Pirouette was not exactly 540 degrees.
Half roll was not exactly 180 degrees.
B8. CUBAN EIGHT - DOWNWIND/DOWNWIND
Model flies straight and level and executes a 5/8 inside loop. When the model is in 45 degree descent and inverted it executes a 1/2 roll in either direction to upright and enters a 3/4 inside loop. When the model is again in 45 degree descent and inverted it executes a second 1/2 roll in either direction and finishes the first partial loop in upright attitude.
Points will be subtracted for the following reasons:
Half rolls were not 180 degrees.
Model drifted toward or away from the judges.
B9. STALL WITH PULLBACK RECOVERY - UPWIND/UPWIND
Model flies straight and level for 10 m and enters the manoeuvre by pulling up into a vertical ascent after passing the center line. After the model comes to a complete stop the model transitions to fast backward flight and must be in level flight when it crosses the center line. Model continues to a point that is at the same altitude and the same distance from the centreline but in the opposite direction and comes to a quick stop with nose pointing down. The model then continues by descending a path that mirrors the entry path. After the descent model transitions to same heading and altitude as at the start of the manoeuvre. Model continues for 10 m to finish manoeuvre.
Points will be subtracted for the following reasons:
Ascending and descending segments were not parallel.
Model did not come to a complete stop.
B10. AUTOROTATION WITH 180 DEGREE TURN - DOWNWIND/UPWIND
Model flies at a minimum altitude of 20 m. Manoeuvre begins when model crosses an imaginary plane that extends vertically upward from a line drawn from the center judge out through the central helipad. Model must be in the autorotative state when it cuts this plane, the engine must be off at this point and the model must be descending. The 180 degree turn must start at this point and the turning and descending rate must be constant from this point to a point just before touchdown on the helipad. The flight path of the model must appear as a semi-circle when viewed from above, starting at the vertical plane and ending at a line drawn from the center judge through the central helipad. The model's flight path must never be parallel to the ground or judge's line.
Scoring criteria:
The maximum score of 10 points can only be achieved when the model makes a smooth touchdown on the central helipad with the skids or landing gear completely inside the 1,2 m circle and parallel to the judge's line. A maximum score of 9 points can be obtained with a perfect landing inside the 1,2 m circle but with part of the landing gear touching the circle (rotor shaft must point to inside of circle when viewed from above). If the model makes a perfect landing inside the 10 m square the manoeuvre can achieve a maximum score of 8 points. If the model makes a perfect landing outside the 10 m square a maximum score of 5 points can be awarded. If the flight path is stretched (flying parallel to the ground and/or judge's line) to reach the square, line or helipad, the manoeuvre will be severely downgraded. If the 180 degree turn is completed outside the 10 m square the maximum score can only be 5 points.
Points will be subtracted for the following reasons:
Model made a hard landing.
Model landed while it still had forward speed.
Model did not perform an exact 180 degree turn.
Model did not maintain a constant rate of descent during 180 degree turn.
Model did not maintain a constant turning rate during 180 degree turn.
Flight path was stretched to reach helipad or square.
If engine was still running during manoeuvre, score will be zero.
F3C JUDGES' GUIDE
5E.1 PURPOSE
The purpose of the F3C Judges' Guide is to provide an accurate description of the major judging criteria to serve as a reference for use in developing a uniformly high standard of judging.
5E.2 PRINCIPLES
The principles of judging a radio controlled model helicopter should be based on the perfection with which the model executes each manoeuvre as described in Annex 5D.
The main principles used to judge the degree of perfection are:
Precision of the manoeuvre.
Smoothness and gracefulness of the manoeuvre.
Positioning or display of the manoeuvre.
Size of the manoeuvres relative to each other.
The requirements are listed in order of importance, however, all of them must be met for a manoeuvre to receive a high score.
5E.3 ACCURATE AND CONSISTENT JUDGING
The most important aspect of judging is consistency. Each judge must establish his standard and then maintain that standard throughout the competition. It is recommended that the contest director or Organizer hold a conference prior to the start of competition to discuss judging so that the standards are as uniform as possible. This can be accomplished with demonstration flights which all judges score simultaneously and privately. After these flights, the defects in each manoeuvre should be discussed by all judges and agreement reached about the severity of the defects. After the competition is started, the individual judges should not alter their standard. Judging accuracy is also very important. Being consistent, whether high or low, is not sufficient if the scores awarded do not fairly reflect the performed manoeuvre.
5E.4 CRITERIA FOR JUDGING MANOEUVRES
A description of each manoeuvre is provided in Annex 5D along with a partial list of possible downgrades. Each manoeuvre should be downgraded according to:
The type of defect.
The severity of the defect.
The number of times a defect occurs.
The positioning of the manoeuvre.
The size of the manoeuvre relative to other manoeuvres.
A high score should be given only if no major defects are noted and the manoeuvre is accurately positioned. Whenever there is doubt a lower score should be given.
5E.5 ATTITUDE AND FLIGHT PATH
The flight path of the model is the trajectory of its center of gravity. The attitude is the direction of the fuselage (canopy, boom, etc.) centreline in relation to the flight path. All judging should be based on flight path.
5E.6 GRADING CRITERIA FOR MANOEUVRE SEGMENTS
The following criteria are furnished to provide the judge with a guide for downgrading deviations from the defined manoeuvre segments. The segments are: Takeoffs, landings, stops, lines, rotations, loops, rolls and stall turns.
5E.6.1. TAKEOFFS
Takeoffs must start from the center of the 1,2 metre circle to obtain maximum score. Takeoffs must be smooth and the model must ascend vertically to eye level. Takeoffs from the edge of the helipad (but with rotor shaft pointing to inside
of circle when viewed from above) result in a downgrade of 1 point. Non-vertical ascents where the model moves forward or backward by half a fuselage length result in a downgrade of half a point.
5E.6.2. LANDINGS
Landings must be centred in the 1,2 metre circle (helipad) to obtain a maximum score. If a portion of the skids or landing gear is outside of the circle (but rotor shaft points to inside of circle when viewed from above), the downgrade is one point for that and the following manoeuvre. A landing outside of the circle (rotor shaft points to outside of circle when viewed from above) results in a downgrade of 2 points for that and the following manoeuvre. Non-vertical descents where the model moves forward or backward by half a fuselage length result in a downgrade of half a point. The landings must be smooth and re-positioning of the model between manoeuvres is not allowed. If the model is re-positioned the next manoeuvre will be scored zero points.
5E.6.3 STOPS
For the hovering manoeuvres the stops must be equal to or greater than 2 seconds in duration. All stops must be of the same duration. If a stop is less than 2 seconds long, a downgrade of half a point should be made. If a stop is greater than 2 seconds, no downgrade should result as long as the model does not move.
5E.6.4. LINES
For the hovering manoeuvres the lengths of the lines are for the most part defined by the 10 metre square. However, the aerobatic manoeuvres must be started and ended by horizontal lines of minimum length 10 metres. A greater length of a vertical or climbing line, resulting from the performance of the model, must not be allowed to influence a judge's score. The length of a line before and after a manoeuvre must be equal. One point should be subtracted for a recognisable difference. If there is a complete absence of a line, before or after a manoeuvre, 2 points should be subtracted.
5E.6.5. ROTATIONS
During a rotation (stationary tail rotor turn), if the model moves vertically or laterally by a noticeable amount, 1 point should be subtracted. If the vertical or lateral movement of the helicopter is significant (more than 25 cm), 2 or more points should be subtracted. During a rotation after a climb, if the model moves laterally by a noticeable amount, 1 point should be subtracted. If the model’s movement is greater than 25 cm, 2 or more points should be subtracted.
5E.6.6. LOOPS
A loop must, by definition, have a constant radius, and must be flown in a vertical plane. It starts and ends with a well-defined line, which for a complete loop, will be horizontal. Every loop must be flown without segmentation. Every clearly seen segment should result in a downgrade of 1 point. If a loop is not flown entirely in a vertical plane, a minor drift should be downgraded by 1 point, while a more severe drift should be downgraded by several points.
5E.6.7. ROLLS
The roll rate must be constant. Small variations in roll rate should be downgraded by 1 point while more severe variations receive larger downgrades. Rolls (including partial rolls) must have crisp and well-defined starts and stops. If a start or stop is badly defined, 1 point is subtracted for each.
5E.6.8. STALL TURNS
The lines during this segment must describe vertical and horizontal flight paths. The model must come to a complete stop before a tail rotor turn is initiated. The tail rotor turn must be around the main rotor shaft. If there is significant horizontal displacement, 1 point should be subtracted. If the model shows a pendulum movement after the rotation, it should result in a downgrade of 1 point. The entry and exit must consist of partial loops with constant and equal radii. Partial rolls must be placed in the middle of the lines. The lines must be recognisable with the lengths at least one times the fuselage length.
5E.7 WIND CORRECTION
All manoeuvres are required to be wind corrected in such a way that the shape of the manoeuvre as described in Annex 5D is preserved in the model's flight path.
5E.8 POSITIONING
All aerobatic manoeuvres must be performed within the 60 degree vertical and 120 degree horizontal viewing angle. Manoeuvres that are flown off center will be downgraded according to the displacement. The downgrade may be in the range of 1 to 4 points. If a portion of a manoeuvre is flown outside of this air space a severe downgrade will occur. If the entire manoeuvre including entry and exit is flown outside of the window it must be scored zero points. Flying so far out as to make the evaluation of a manoeuvre difficult should also be severely downgraded. The main criteria here is visibility. Manoeuvres performed on a line further out than 100 metres away but in front of the judges should be downgraded in any case because even the keenest eye begins to lose perspective at that distance.