Links to more information:
Last update: 1/3 2009
Online debat forums:
CL Combat, Combat-1 and CL_Combat_Shutoffs (Yahoo Groups)
Russian Aviamodelny Sports Forum - Translat to English by Google
MACA - F2D
Barton Model Flying Club
f2d.free.fr - Translatet to English by Google
Homepages with shut-off info:
The debate on the Internet:
Shut-off in all classes - 24/2 2008
CIAM and the shut-off debate - 24/2 2008
Shut-off and DQ problem - 28/11 2007
3 and 5 second rules - 19/11 2007
Bill Lee - 27/11 2007
Tactical reflights - 22/2 2006
There has been a big debate on shut-offs and rule changes in a couple of Yahoo Groups.
This page contains some of my contributions to this debate. To avoid any conflicts with copyrights I have chosen only to bring my own comments.
Some of the contributions are comments to the contributions of others and some of my comments have been commented by others.
Please follow the links to the Yahoo Groups to see my comments in the right context.
Shut-off in all classes:
From Yahoo Group: Combat-l - 24/2 2008 - Message 15735
Most people probably think that the new shut-off rules only concern combat.
It is not so. The side effects of this rule are much deeper and wider than most model flyers realize.
Let's take a look into the future and see how the situation will be after shut-offs have been made mandatory in combat.
Now, imagine a situation where somebody has been injured or even killed in an accident with a Speed, TeamRace or Stunt model. How will our positions be and which arguments will be used against us in a lawsuit?
1) We have introduced the mandatory shut-off system in combat because we have considered that a combat model is dangerous in the event of a fly-away.
2) Stunt, Team Race and Speed models do have higher impact energy than combat models. This meaning that these types of models are more dangerous than a combat model.
In court the pilot, contest director and the control line model flying organizations now have to explain why this Speed/TeamRace/Stunt model did not have an anti fly-away device when it is mandatory for the less dangerous combat models! It is hard to find any arguments that justify this and there will be basis for a really huge lawsuit.
The fact that dangerous events are very rare in these classes do not change the situation. There will still be a probability of an accident and a huge lawsuit against all involved. The key point here is to understand the difference between the chance of an event and the consequences of the event. One example: The problem with "Russian Roulette" is not the chance of "winning" but the consequence if you "win". You can not turn Russian Roulette in to good clean family entertainment by changing the odds of winning to, lets say, one in a million. The problem is the fatal consequence if you win, not the odds for winning.
By letting the less dangerous class be the first to introduce the mandatory shut-off we put the other classes in a real bad position.
Competition organizers will be under threat of a huge lawsuit. If nobody dares to run this new risk, the only solution will be also to introduce mandatory shut-offs in these classes.
As you can see the shut-offs rule is not an issue that only concerns combat. Speed, Team Race and Stunt pilots will be highly affected by this new rule. It would therefore be reasonable also to hear their opinion in the discussion.
A reasonable debate on this new subject can not be done before the CIAM meeting.
Regards, Henning Forbech
You will find more on the impact energy calculations here:
CIAM and the shut-off debate:
From Yahoo Group: Combat-l - 24/2 2008 - Message 15734
In a month the CIAM meeting in Lausanne will decide which rules will be effective from January 2009. For combat the most radical change of the rules is the mandatory shut-offs.
Last November there were a lot of discussions about shut-offs in this forum. When I look back I can see that there are two arguments from that discussion that I would like to comment on:
"One accident can kill combat"
"The big lawsuit"
The risk of a lawsuit is a real problem for the American model flyers and they need to find a solution. From my point of view the new shut-off rule is not a solution to this problem. I fact it is going to make things much worse!
Regards, Henning Forbech
See an example of the use of these arguments here:
Shut-off and DQ problem:
From Yahoo Group: Combat-l - 28/11 2007 - Message 15443
Proposals for new rules that have been send forward to the CIAM Control Line Subcommittee meeting this weekend. One rule is concerning disqualification if the shut-off is not working:
4.4.15. Cancellation of the Flight:
This simple rule can lead to some unexpected problems:
Imagine a situation with a DQ rule for a not functioning shut-off and pilots fly with shut-off systems with a success rate of 90 %. (Some pilots will probably even block the shut-off systems because the risk of a DQ is lower than the benefits of avoiding the trouble with unreliable shut-off systems).
If a pilot is about to lose his fight some might be desperate enough to go for there opponent`s lines. If his model flies away and the shut-off doesn't work he will be disqualified and the "desperate pilot" will be declared the winner.
A solution to this problem could be to let both pilots be disqualified in the event of a fly-away.
I see no simple solution to this problem but good and reliable shut-offs would minimize the problem. If the shut-off rule is implemented too early we might end up in a scenario with even more dangerous situations than we see today.
Once again: I recommend that the shut-off rules are postponed for a year !
Regards, Henning Forbech
Re: 3 second shut down problem...........
From Yahoo Group: Combat-l - 19/11 2007 - Message 15355
This commet was a respond too Message 15340
If you read the proposals for new combat rules you will find both a 3 second AND a 5 second rule.
The 3 second rule:
The 5 second rule:
This discussion on the activation time is not new.
PS: Here is some of the old background information to 3 and 5 second rules:
Section 4.4.6: Controls - Technical Verification:
Section 4.4.15: Cancellation of the Flight:
For more information visit:
or find it here:
From Yahoo Group: Combat-l - 27/11 2007 - Message 15427
This commet was a respond too Message 61
I have transferred some of the comment in the "Combat-Shut-Off" group to this group since my response to it is more a general comment than a technical issue.
In a response to Göran Olson's comment on my shut-off project Bill Lee wrote:
Maybe I didn't make my point clear enough on my website so please let me try to explain the idea behind my shut-off project:
First, I didn't give up on my mechanical shut-off because it didn't work. I shut it down because it could not be used as a general shut-off system in F2D-combat !
I was (and still am) looking for a shut-off design that can generally be used in combat. Not just by me and other DIY nerds but a system that will suit all pilots. This ideal system should solve the fly-away problem with minor side effect on rest of the F2D combat as possible and it should be made available to all pilots.
Any shut-off design will have an effect on the whole F2D combat buisness. A very expensive shut-off system would ground those pilots that can't affort them. Self-made shut-offs would ground those who can't produce their own system. Complicated systems will set pilots without a well trained pit crew out of the game. Etc.
If the shut-off rules are introduced before we have a well designed, well tested, available ready-to-use systems and a set of consistent rules there is a high chance of a serious reduction in the combat activity in the next years. I have not yet seen any of these matters been fulfilled but more people are now starting to work with these problems. This is why I recommend that the shut-off rules are postponed for a year. More time is needed to develop the shut-offs and to get the rules ready for this new situation.
From Yahoo Group: cl_combat - 22/2 2006 - Message 433
Flyaways do happen as simple accidents. That's bad enough.
But some flyaways seem to be part of a tactical game where a pilot in a "hopeless" situation sees a flyaway as his chance for a second attempt.
A small change to the rules might prevent pilots from attempting to cut lines as a part of a tactical game:
If a pilot has a flyaway, he can ask for a reflight. But he should only be given the reflight if his score is higher than his opponent!
Well, we might see fewer pilots asking for refligths after "simple" accidents. If the unlucky pilot isn't sure of his position, he will probably let the fight go on instead of risking not getting a reflight.