At some point I think an intelligent man would consider the safety margin. Our club once contacted AMA for guidance on some high performance unofficial events we were running and they were very helpful. I would guess they might tell you to use modern combat specs.
126 mph on .015 stranded? AMA slow rat is about that fast on .016 solids or .018" stranded. Early 70's when I was in combat we were on lighter stranded lines and high nitro fuel. Don't know when they changed those things but, they were changed for a reason I'm sure.
I think AMA Speed has some kind of speed/weight formula for line size. If I were making a speed type event I would have a look at those calculations.
If I get my plane done for the contest it will be on .018" stranded and 10% nitro but I don't expect to set any speed records, just have fun.
Motorman
120 days who cares. Good topic to revive.
The question was line sizes. The AMA made a fiat change(well maybe somebody did propose it) after the 1976 NATS. There were multiple flyaways, both double flyaways with line wraps and single flyaways from broken lines, in both Fast and Slow.
The next year 0.018 lines were mandated for anything over a 15, and safety thongs were required on every flight.
In 76 a LOT of pilots were flying with a loose, open finger-tip hand grip. Any kind of hard tug could pull the plane out of the pilot's hand.
0.015 lines were just too fragile for 100+mph line tangles. They either popped easily, or both pilots let go and there was a line tangle/flyaway. There were several of these in the first three rounds(double elim first round?). Something similar happened in Fast but not as many. Most of the Fast flyers had flown it for at least 5-6 years at some big contests and got more combat flying time and learned more tricks to survive.
I think Howard CD'd this event. He may have better memories or maybe even some notes.
Phil C