Triangular flight
As triangle flight a rating category in the haul flight referred to in which the pilot of a glider , hang glider or paraglider returns over two turning points to the starting point.
For a valid triangle flight, the triangle cannot be too narrow (i.e. the shortest side must exceed a certain percentage of the other routes). Triangle flights place the highest demands on planning and implementation and are considered the supreme discipline.
The route flown - especially at the turning points - is checked by recording the GPS route , historically also by means of barograms in connection with aerial photographs of the turning points.
Record lengths and requirements
The record distances in triangular flight with gliders have been well over 1000 km since the 1970s and over 300 km for paragliders since the 2010s. The greatest difficulty is usually the correct assessment of the weather conditions and the updrafts required for a long cross-country flight , as well as fatigue.
In order to make good use of the thermal and slope updrafts, the pilot must be physically fit and able to concentrate fully . Before the start, the weather and flight planning must be carried out. Depending on the rating category, the planned turning points can be reported in advance via a sports witness, which is rather unusual for paragliders. To cover these intermediate distances, a compromise is usually chosen between maximum speed (with expected downwinds) and the best gliding .
During the flight it is necessary to constantly navigate , especially at the turning points and before landing , and the weather must also be closely monitored. Because the return often brings completely different wind and updraft conditions, the achievable distances in triangular flight are "only" about half of the distances achievable in straight cross-country flights (here the world record has been over 3,000 km or 500 km for paragliders for several years). The speed record in long-distance triangular flight with a glider is 169.7 km / h (92 kn ) over a 1,000 km triangle, set up by the German Helmut Fischer on January 5, 1995 in South Africa.
Weather and Risks
Cross-country flights of up to 10 hours mean high demands on body and mind as well as high mental stress, because successes and failures follow each other and you have to deal well with the resulting emotions .
Even more than in a straight cross-country flight, the pilot has to make a multitude of decisions during a triangular flight . They include in addition to the principal, but the move eventually variable choice of route monitoring and evaluation of terrain (cartography) , regional and local weather, the scheduling , the "emergency program" (ultimately possible locations for field landings ) and dealing with only vague information. The choice of updraft zones and the duration of the “ cranking ” in them have the greatest effect . The shape and type of clouds are an important indicator of this - especially cumuli and leeward clouds . The cloud base is also an essential and easily ascertainable variable for the state of the atmosphere.
Individual differences in the degree of caution and foresight have the second strongest influence on success and the possible flight duration. A more cautious pilot prefers to fly out every “beard” (thermal tube) up to a great height - because only a sufficient height difference can be converted into the route to the next updraft. This behavior, which is common among beginners, serves safety and prevents time-consuming and costly landings for gliders, but it stands in the way of record distances.
For record distances, on the other hand, you have to reach the strongest updraft and fly the long stretches in between at top speed. The triangle flight has a small advantage over the classic cross-country flight, because you already know parts of the flight route and their slope inclinations on the return flight, as well as the possible outside landing areas. However, it is usually best to find a compromise between caution and risk . In the evening you often have to fly through wide areas with a light or stronger downdraft , or the route is partially covered by terrain-related shields. A sufficient reserve of altitude must always be planned here, as well as when flying over watersheds and passes .
Web links
- LSV Osterode, "cross-country flight" (with map, wind and barogram )
- Detlev Hoppenrath on his 50 km test flight
- Triangle flight with prototypical model gliders
Individual evidence
- ↑ Honorin Hamard (FRA) (17 894). October 10, 2017, accessed May 9, 2019 .