Legal control lines.

[Ty Marcucci]

 

[Paul Smith]

You are correct.  Steel lines are a known commodity with constant and predictible strength.

Plastic and other syntheic fish lines are a bowl of jelly that defies safe measurement.  Thus, any contest organizer who values his personal survival will stay with what has been proven to work.

Of course sport flyers can do anything they want at theit own risk.

[Randy Cuberly]

I think there was an effort to legitimize some type of fishing line (the exact name escapes me at the moment), but as far as I know, it failed.

Randy Cuberly

[Tim Wescott]

When in doubt, read the rules.  It's not hard, they're posted on the AMA web site, and no one is going to demand a quart of blood for the privilege of looking.

This from my copy of the 2013-2014 Control Line General rules:

2. General. A Control Line model is flown on one or more' steel or GSUMP, commonly referred to as
Spectra or Dyneema, lines' steel wire line(s) or metal line(s) of equivalent strength, attached to the model in
a manner providing aerodynamic control of the model’s elevation through manipulation of the control
surfaces during flight.

If you doubt me you're welcome to go look on the AMA web site and read the rules fresh from there.

As far as I know the only competition class where Spectra lines are allowed is combat.  This makes sense because combat lines take a beating, and Spectra lines seem to be better able to handle that than steel lines do.  Moreover, combat planes often suffer from line breakage, and the combat community has the safety issues relating to that figured out.

[dave siegler]

read control line general section 5.3.5.1


5.3.5.1 Spectra Lines.
Lines made of Spectra fiber, made of gel spun ultra high molecular weight polyethylene are
permitted for sport flying and demonstration purposes. Spectra lines are not permitted in competition
unless the specific rules for the event flown expressly permit such use. The use of high visibility yellow
lines is recommended, but not required.

Each SIG had the option to approve them or not,  combat did a lot of work to certify them. 


Combat allows them everyone else does not. 

I have used them for sport flying and love them.

Note  I don't think Dacron lines were ever specified for 1/2a.

[Trostle]

Each SIG had the option to approve them or not......

Just for the record ---

Special Interest Groups (SIG's) do not approve rules changes.  SIG's can certainly make recommendations to their appropriate Contest Boards.  The  Contest Boards approve rules changes for their respective events.

Keith

[Tim Wescott]

Thanks for those ruels Tim. I can not get into the AMA site. Seems it no longer accepts my password, so had to get a new one. Still waiting. My rules are for 2011-2012. 

Hey Ty:

I've never had to log in to the site to get to the rules -- those are out in the public part.

Bummer about your password, I hope HQ gets you going again.

[Trostle]

Thanks for those ruels Tim. I can not get into the AMA site. Seems it no longer accepts my password, so had to get a new one. Still waiting. My rules are for 2011-2012. 

As far as I can tell, anyone can have access to the AMA site.  No password is needed to look at the rules section.  Somebody correct me if I am wrong.

http://www.modelaircraft.org/

Keith

[dave siegler]

Just for the record ---

Special Interest Groups (SIG's) do not approve rules changes.  SIG's can certainly make recommendations to their appropriate Contest Boards.  The  Contest Boards approve rules changes for their respective events.

Keith

opps I knew that sorry.

[howard shenton]

Spectra lines ARE legal for combat as stated above.
Phil Cartier has been using them at our contests (Metrolina Control Line Society) since they became legal and had been experimenting with them before they became legal.
Never had any problem with his lines.
I think they started out yellow but bleached out to white.

Howard Shenton

[john e. holliday]

This guy must be from the era when the Kevlar lines were put on the market.   I remember one of the guys in the club tried them as he thought they might be better  for maintenance and usage.   One flight was enough to convince him they were trash.   Oh they stood the pull test for the combat model.   But, the lines at that time were not round.  They had kind of a squarish look to them.   Not only did they ossilate, but they hung up after a half dozen loops.