@Doug Holverson S8 is flown a couple of ways. The vanilla S8x event is flown in 3 rounds with a max time each round based on the motor class.
There is a chart in the FAI Spacemodeling rules that shows the minimum wingspan, maximum launch mass, and max time per impulse class.
CLASS | TOTAL IMPULSE Newton-seconds | MAX WEIGHT g | MIN WING SPAN mm | MAX FLIGHT TIME sec |
S8A | 0.00-2.50 | 60 | 500 | 180 |
S8B | 2.51-5.00 | 90 | 650 | 240 |
S8C | 5.01-10.00 | 120 | 800 | 300 |
S8D | 10.01-20.00 | 300 | 950 | 360 |
S8E & S8P | 20.01-40.00 | 300 | 1100 | 360 |
S8F | 40.01-80.00 | 500 | 1250 | 360 |
So for S8D you build (or convert) a model with a minimum span of 950mm that weighs less than 300g (ready to fly), and you fly it 3 times trying to achieve a max time of 6 minutes. You can earn 60 bonus points if you land any part of the model within a 15m square box on the ground. The time in seconds is converted into points, and your landing bonus is added so the maximum score in a round could be 420. You fly 3 times, add up all the scores, and if there are any ties there is a flyoff round.
The P version of S8 has been flown at the E impulse level (and size/mass limits) and adds a precision task. During a 12 minute working time window, you need to launch, fly a 6 minute flight, and land at a designated landing spot. Each second you are timed is a point. If you go over 360sec you start losing points for each second. If you land on your spot, you get 100 extra points. For every 10cm away from the spot the nose of your model lands, your landing bonus goes down by 1 point. All the scores are normalized so the highest score gets a 1000, and the rest are assigned relative to that score.
S8EP pilots at the WSMC flew in 4 rounds, the top 5 pilots at the end of those rounds were advanced into 2 final rounds where they flew head to head. The combined scores from those 2 rounds determined the top 5 places.
There was a rules change for the S8P version that keeps the size and mass limits of the E class event, but lowers the impulse to a D (20 Newton-seconds max). Planes that were good at E impulse (1.5m DLG converts) will not be as good in the event going forward.
If you are looking to get into the event, converting a small, cheap 1m DLG is a good way to go, you will need to add some span for the P event. There are some inexpensive ones out there (See the Big Vick from Hyperflight in the UK
https://www.hyperflight.co.uk/products.asp?code=BIG-VICK&name=big-vick-1m-dlg for $55, but you can also go out an buy very expensive molded planes too ($400-$700). Either way, you will need to add a motor mount (18mm for D reloads from Aerotech) but the beauty of converting a DLG is you can always fly it as a DLG for practice.
kj