2.4 In Stunt ?

[Skip Chernoff]

Are we allowed to use a 2.4 radio  to control retracts and fuel shut off in our C/L stunt ships at an AMA sanctioned meet? Thanks, PhillySkip

[Russell Shaffer]

The AMA stunt regulations permit retract operation and a one time fuel shutoff.  The gear has to be extended for landing and the fuel shutoff has to be "irreversible". 

[Tim Wescott]

The AMA stunt regulations permit retract operation and a one time fuel shutoff.  The gear has to be extended for landing and the fuel shutoff has to be "irreversible". 

I don't know why -- because I have no problems with timers, or with electronics gizmos that sense shutoff loops -- but I just don't like the idea of an RC fuel shutoff.  Even more puzzling, I have no problem with an RC throttle for scale or Carrier.  Keep stunt pure, maybe?

[Russell Shaffer]

2.4 RC, timer, electronic gizmos - all same same.

[Glenn (Gravitywell) Reach]

Personally, I think it would be great to see the landing gear go up and down on any of the semi-scale stunters out there.  Whats the big deal?  If the rules allow for it, go for it!

[Steve Helmick]

I'd bet that the answer is on the AMA website...     Steve

PS: During this weekend's Ring-a-Thon, the subject of T.U.T. came up. We agreed that Tim dropped the ball, and it should have been called "Tim's Ingenious Timer".   

[Tim Wescott]

I'd bet that the answer is on the AMA website...     Steve

PS: During this weekend's Ring-a-Thon, the subject of T.U.T. came up. We agreed that Tim dropped the ball, and it should have been called "Tim's Ingenious Timer".   

But of course.

[Trostle]

From Paragraph 2.6 of the AMA CL Precision Aerobatic rulebook:

"2.4 GHz spread spectrum radio control signals may be used to control
retraction or extension of landing gear and/or a one-time irreversible
engine or motor stop function. Otherwise, all control of the model during
flight shall be through the flying lines. The retraction/extension of the
landing gear and/or motor/engine stop function shall be under the sole
control of the pilot and may not be operated by any other means that direct
pilot control. No other uses or any other means of wireless remote control
are permitted. The burden of proof of compliance with this rule is on the
pilot. If, in the opinion of the CD or designee, the system is not compliant,
the model is disallowed from competition until the system is disabled or
removed."

Keith

[Howard Rush]

During this weekend's Ring-a-Thon, the subject of T.U.T. came up. We agreed that Tim dropped the ball, and it should have been called "Tim's Ingenious Timer".   

The airplanes I dealt with at work typically had one total air temperature (TAT) sensor.  One customer wanted two.  I came up with a box that switched between the two TAT sources.  I named it the Transfer Interface Terminal (TIT for TAT).  I don't think the nomenclature stuck. 

[Brett Buck]

2.4 RC, timer, electronic gizmos - all same same.

      I wrote that rule with the idea that it was either irrelevant (shutoff) or kind of neat but not particularly advantageous (retracts).

      But note the rest of it - this rule eliminated far more things than it added. Before, IR or RC* throttles/shutoffs/retracts/closed loop mixture control/closed-loop tracking with autopilot feedback/anything you can think of was perfectly legal. For example, the ZTron IR control unit that Zigras developed and Windy used was legal at the time, and before and after (and no, there was no conspiracy to ban him, or anyone else afterwards). It became illegal only with this rule change 15 years after the fact.

     Brett

*Note also that 2.4 GHz was made specifically legal in a different proposal to CL General, I think in the same cycle. This change specifically defined what it could be used for and not used for in stunt, knowing that the other proposal would pass.

[Crist Rigotti]

The airplanes I dealt with at work typically had one total air temperature (TAT) sensor.  One customer wanted two.  I came up with a box that switched between the two TAT sources.  I named it the Transfer Interface Terminal (TIT for TAT).  I don't think the nomenclature stuck. 

This made me laugh out loud!  Thanks Howard.

[Skip Chernoff]

Thanks all for jumping in here on my question. I much appreciated the rule book section being posted specifically detailing what is allowed regarding this matter. Thanks Much.....PhillySkip

[Dennis Toth]

Now what we need is a small clicker size device that uses the 2.4 radio spectrum to activate a simple shut off. This would make life in IC land very happy. Being able to shut off when you want allows getting out of the circle faster if you have a bad setting (possibly saving the engine), allows the contest to move quicker and minimizes end of tank issues from not being able to carry enough fuel for a clean last maneuver. Anyone making these?

Best,    DennisT

[Dave_Trible]

Dennis I have a source who made a couple for me.  They are used for free flight dethermalizers and some FAI combat.  I'll dig up the info when I get home.  That's the easy part.  I've found the harder part is building a reliable but powerful enough device to pinch off the fuel line.  It about has to be a spring load affair that a very light duty servo can still trigger.  This unit I have from him actually twists the line closed.  You have to use very soft thin wall tubing AND mount the servo in the line between tank and engine- no small feat in a cowling.

Dave

[Dennis Toth]

Dave,
Sound good, look forward to the information. For the shut off maybe a simple squeeze off arm that the servo closes and some soft thin wall surgical tubing (I think the free flight guys sell this) would work.

Best,   DennisT

[Dave_Trible]

Here is the setup.  About a year and a half ago what's shown would cost about $150.00.  The supplier:
Micro Flier Radio
(Microflierradio.com)
Sarasota, Fl.
(914) 377-9808

A real nice gent runs this business

Dave