British Paragliding Cup 2008

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How do I join a gaggle?

You MUST approach at a tangent. Do not fly in a direct line to the centre of the thermal - this is a problem that has affected us all. If you see a pilot or a gaggle thermalling, dont fly a direct line straight in to join them. It is most disconcerting to be on a potential collision course even if you know the inbound glider is more than likely to make a course correction before contact. But since we are all responsible to avoid mid air collisions we must take avoiding action before its too late to do so. This can upset the dynamics of many gliders all in harmony in the same thermal.
Enter the thermal at a tangent and gradually slot in to place. As the size of the gaggle gets bigger it will naturally have to get larger to maintain separation. When this happens, dont make a bee line for the central core, because this will scare the pants off the pilot on the other side of the circle.

The following is from the FAI.

1 THERMALLING RULES AND TECHNIQUES

It is apparent from the experience of many pilots and officials at events that quite a few pilots do not know how to thermal effectively and safely with a large group of pilots. Despite the CIVL qualification requirements for the entry of these events, not all countries teach proper technique and etiquette, or may not know the universally accepted procedures. In order to enhance the safety of competitions, these rules are presented, which must be read and understood by all pilots entering CIVL sanctioned competitions.
1.1 Aggressiveness

One of the biggest problems in competitions with many pilots is the over-aggressiveness of certain individuals. Over-aggressiveness in crowded skies can lead to mid-air collisions, which can lead to fatalities. Nearly every pilot in a crowded thermal would like to circle tighter to better use the core, but it is impossible to do so without a great disruption of the entire circling group. A pilot that makes close passes to others or avoids clearing all turns endangers everyone, and risks the anger of his fellow pilots which may cause later confrontations. An overly aggressive pilot ultimately hurts his or her own long-term competition results.

Competition directors are required to deal with overly aggressive and unsafe pilots in the following manner: The pilot should be given a warning as soon as a confirmed report of the pilots dangerous behaviour is presented. If the pilot doesnt stop the dangerous behaviour immediately, the pilot must be removed from the competition.

1.2 Entering a thermal

1.2.1 First rule - TURN IN THE SAME DIRECTION AS THE PILOTS ALREADY IN THE THERMAL (either clockwise or counter clockwise).

This rule holds strictly even if the thermal is entered well above or below the previous pilot(s). The reason for this last point is that often, lower gliders will climb more quickly and may eventually be at the same level as the higher gliders. Also, in crowded skies it is common for many pilots to join a thermal and pilots coming in between two pilots turning different directions will not know which way to turn. Often this factor results in several groups of pilots at different levels turning in different directions. When these groups merge, chaos and endangerment occurs.

So it must be stressed: Always enter the thermal in the same direction as a previous pilot no matter what the height separation. Often pilots have a turn direction preference, which induces them to turn opposite to the direction already established. Pilots with such strong preferences should not enter a competition until turning to the undesirable side is practiced to the point that the pilot is able to automatically turn in either direction.

Which way should a pilot turn when entering a thermal in which pilots are turning in opposite directions? This problem is common enough and difficult. If the pilot is closer to one group (above or below), its best to turn in the direction of that group. A pilot approaching a thermal with other pilots at similar height must circle in the same direction as the first pilots that reach the thermal.

In general, if a pilot is midway between an upper and lower group it is best to circle in the same direction as the upper group, as these gliders cannot be seen well. If the lower group climbs more quickly, these gliders can be easily seen and the turn direction reversed if required. Do not wait until they are at your level to reverse, since it may result in a mass confusion as some pilots change direction and others dont. Besides, the reason they are climbing up to you may be that their turn direction is more efficient due to a rotating thermal.

1.2.2 Second rule - APPROACH THE THERMAL TANGENTIALLY TO THE OTHER GLIDER'S CIRCLE ON THE SIDE WHERE HE OR SHE IS FLYING AWAY FROM YOU.

This procedure allows a simple turn to be made to follow the previous pilots circling path even if both pilots are at the same level (see figure 1). Approaching a thermal circle at any point other than the tangent (where the joining pilots flight path just touches the circle diameter) is extremely dangerous. Pilots doing so are guilty of inducing confrontations and possible mid-air collisions.

NEVER FLY THROUGH THE MIDDLE OF A THERMAL CIRCLE.

Thermalling Figure 2 It is ideal to arrive at a thermal circle when the pilot already circling is on the opposite side of the circle. The pilot who has established the circle must be watched to see where the tangent point is on the side of the circle being entered. By watching the pilot for two or more 360-degree turns as the thermal is approached, a suitable entry point can be determined and the entering pilot can safely join the circling pattern.

Sometimes the circle is reached when the circling pilot is on the entry side of the thermal. In this case, the approaching pilot should circle on the normal side, but further out from the centre to give the other pilot room to continue to circle with no variation in the established pattern. The entering pilot should then start circling in the same direction with a bigger radius as shown in figure 2, which will soon allow room behind the other pilot so that the ideal path can be joined by tightening up the turn. Naturally, the pilot already circling should maintain a regular circle, both so the other pilot can judge where to be, and to maintain the core position. Cooperating in this manner is what the top pilots do in order to fly more efficiently and assure safety.

1.3 Multiple Cores

Quite often multiple thermal cores exist in close proximity to one another. This feature presents a real problem in crowded skies, because these cores often merge as the thermal rises higher. In this instance, when a good core is encountered as a thermal climb is approached, which way is it best to turn? There are benefits and problems relating to turning in either direction. If the turn direction of the nearby circling pilot is adopted, it is possible to enter the established circle simply by making a wider turn as the other core comes closer. On the other hand, the turning gliders will be approaching head-on at the near part of the circle as the cores merge (see figure 3).

Thermalling Figure 3 If the approaching pilot chooses to circle in the opposite direction, there is not as much head-on confrontation, but the pilot must do a full turn reversal to join the other circle as the cores merge. If other pilots have joined the new circle, this turn reversal can create great confusion and potential conflicts. For the latter reason it is recommended to turn in the same direction as other pilots in a nearby core.

Often thermals can be broken with light multiple cores appearing for a few turns then disappearing. This situation may be a result of weak heating, wind or an inversion layer. When a group of pilots are trying to work such conditions, conflicts can result. Generally, the only safe policy is to use common courtesy and good airmanship. If the cores are short-lived, it doesnt make sense to rush around like crazy towards each pilot that tightens up in a better core. All this does is create conflict with other gliders and the erratic pilot will usually miss the core while knocking out the original pilot or lower ones coming up.

The best policy is to wait until the climbing pilot is clear and enter the core without conflict. That way the entering pilot can tighten up successfully and gain the best climb. Blundering through the group trying to grab everything that is marked will just anger the other pilots who then wont cooperate and will do everything they can to block youre the offending pilots progress. Remember, overly aggressive pilots ultimately hurt themselves psychologically.

In broken thermals, all pilots should orbit in the lifting area and allow a pilot that hits a surge of lift to tighten up and climb above. That way the crowding becomes less and everyone will have a better chance of getting up. Remember, in such conditions all pilots are your helpers, at least until you get close to goal. The weaker and more rare the lift, the more you need other gliders around to cover more area to find thermals. If you play the game of forcing others out of the lift you find yourself alone in an often fruitless hunt for lift.

1.4 General Rules

1.4.1 MAINTAIN CONSTANT AWARENESS

That means looking around continuously to avoid conflicts. You must look to the outside of your turn as well as inside, for often gliders outside of you get forced inward or circling path get offset. Do not get confused by the mass of gliders above or below you. Focus on the ones at your level and a bit above and below.

1.4.2 MAINTAIN A REGULAR, PREDICTABLE TURNING CIRCLE

Try to keep the same radius turn without varying it so other pilots know where you are going to be as they come around each time. Some pilots get fearful as the crowd increases and they flatten out their turns. This results in a reduce climb rate for everyone and even more crowding as more pilots end up at the same level. Maintain as tight a turn in the core as possible for maximum climb so pilots get spread out vertically, not horizontally.
Two pilots on the same level can work together very nicely at quite steep banks. To do this, maintain a constant bank and remember, as long as you cant see the other pilot he or she has either climbed above you or is on the exact opposite side of the circle and you will not hit. If you flatten out you may end up with a conflict. Three pilots can also work together in this manner if each pilot is very careful to keep a regular circle and the lift is smooth. Four pilots at the same level are too many for the efficient use of most cores.
Be aware of the fact that it always appears that the other pilot is going around your circle. This visual mirage makes you think that the other pilot is turning flatter than you. Dont make this perception error and flatten out or youll cause conflicts. The only way to tell who is turning flatter is to see who catches up to whom. If you are catching up to the other pilots, you are turning more steeply, and vice versa.
Many pilots use techniques of quickly altering their turns when surges of lift pass through. This practice is overly aggressive in very crowded situations and will eventually get reported with a subsequent penalty. No pilot has the right to endanger others for his or her gain. Pilots should study available publications regarding thermal techniques and thermal procedures.