The Mystery Of The OLC Triangle

[youngbl...@gmail.com]

As you all know I am a big advocate of the triangle flight, mostly all types except equilateral triangles here in the soaring community. I often look at the FAI triangle distance to determine the complexity of the flight which I look at things like terrain covered, and distance along with triangle speed. To me those are the big factors in the quality of a flight.
Yes, I could run up and down the sea breeze front all day long and I would feel like I was not accomplishing anything other than having a fun flight. I could run up and down HWY27 and consider that a fun flight.
When I look at some of the FAI triangle or distance scores they are somewhat confusing, I guess that I am not the only one to wonder just how OLC determines their triangles. Maybe instead of six types there should be adding another called the OLC. Old Bob, The Purist

[John Godfrey]

This is what the OLC rules say (maybe they have a bug?)
https://www.onlinecontest.org/olc-3.0/segelflugszene/cms.html?url=rules_overview/b2_en

4.3.2 FAI OLC Course (based on the FAI)

If possible, three turn points are chosen on the recorded, closed flight path such that they define an FAI triangle with the greatest possible circumference, whereby

- the shortest leg must be at least 28% of the FAI distance
- if the FAI distance is 500 km or more, the shortest leg must be at least 25% and the longest leg at most 45% of the FAI distance.

The departure point can be between two turn points of the triangle. The flight path is considered to be closed if the finish point is within 1 km of the start point, and the departure altitude is not more that 1000 m above the finish altitude. (Tip: If an FAI triangle is planned, a departure point should be defined before the flight, which can then be approached on the return flight.)

[Mark Mocho]

Another thing to remember is that "OLC-Plus" scoring takes the optimized straight distance over the six allowed OLC legs of the flight and adds 30% of the optimized triangle distance. This was adopted around 2011 to encourage triangle flights as opposed to straight runs up and down a ridge, cloud street or other energy line.

[Moshe Braner]

On 3/23/2023 9:26 AM, John Godfrey wrote:
> ...

>
> 4.3.2 FAI OLC Course (based on the FAI)
>
> If possible, three turn points are chosen on the recorded, closed flight path such that they define an FAI triangle with the greatest possible circumference, whereby
>
> - the shortest leg must be at least 28% of the FAI distance
> - if the FAI distance is 500 km or more, the shortest leg must be at least 25% and the longest leg at most 45% of the FAI distance.

I wonder why the rules are set up differently for distances above 500
km. Why not keep the 28% rule for all distances? 25% is not very
different. Was this designed to accommodate the shape of some island
nations?

[Mark Mocho]

Was this designed to accommodate the shape of some island
> nations?

No, it is simply to allow for a slightly longer leg that corresponds to common flying conditions that allow for a longer run along either a mountain ridge, cloud street or other energy line. If you sketch out a 25% minimum 45% maximum triangle, you will see that it is a bit "flatter" than the 28% minimum triangle, which becomes closer to the "ideal" equilateral triangle. Thus, a slight advantage is given for triangles over 500 km, which by their very nature, are more difficult to achieve. It also forces pilots to not rely on a ridge run with a slight lateral deviation to make the "triangle."

[youngbl...@gmail.com]

Actually triangles by definition are much more difficult that the OLC triangle. Whether it be Isosceles, Scalene, Equilateral, Acute, Right Angle, or Obtuse, they are much more difficult that the FAI definition of a triangle. Sure you can make a T and get triangle points under FAI rules, but by definition the actual triangle flown does not exist. I have yet to see an Equilateral triangle posted, most of the triangles posted are Scalene, Obtuse or Obtuse, then you have the OLC, FAI version. Old Bob, The Purist

[youngbl...@gmail.com]

Standby, something good is coming. OBTP

[youngbl...@gmail.com]

Now guys, this is about the real triangle, Price , go back to Georgia with your tail between your legs, and OBTP has yet to fly. That up and down flight does not compare to the real triangles of TCSC. Maybe I should say TSTC, Treasure Coast Triangle Club. Todd. good flight and great tow, OBTP. I think that next year we will have the Florida triangle challenge, inviting the top 10 Florida triangle fliers to compete in the TCTC, Treasure Coast Triangle Club.

[John Godfrey]

As to how OBTP determines a real triangle - "I can't define it, but I know it when I see it."

[youngbl...@gmail.com]

I guess the geometry books will have to be changes by adding a new chapter called, "If It Looks Like A Straight Line It Must Be A Triangle" as says FAI. OBTP

[youngbl...@gmail.com]

As if you guys didn't notice there were some more real triangles hung on the scoreboard today. One of the real triangles was 500k plus that took Nelson deep into the unforgiving Everglades swamp to a place called Dade Collier. and back around the West side of Lake O and back across to the Treasure Coast.
I also saw those Big Bogs posting those straight line flights following HWY 27 except to make a dash like the Little Dipper. Anyway, Jared had a nice flight down toward Montgomery Ranch and back up Hwy 27 to the hovel, I must give Jared the PURIST flight of the day. OBTP