Timers for F2B ???????/

[Vincent Corwell]

Hola friends

Are timers now allowed in F2B, to stop the engine run???

Vincent

[Paul Smith]

[b]YES, effective 1st January 2007.[/b]

Also, please note that the FAI requires only 1.5, not 2 laps between manouvers.  This makes 7 minutes a bit easier to achieve.   Not on every manonver, just on some: reverse wingover, inside loops, inverted, overhead eight, and cloverleaf, a potential of 25 to 30 seconds here.

[Kim Doherty]

Hola friends

Are timers now allowed in F2B, to stop the engine run???

Vincent

Vincent,


Here is the current FAI F2B rule:

4.2. CLASS F2B - AEROBATIC MODEL AIRCRAFT

4.2.1. Definition of an Aerobatic Model Aircraft
Powered control line aerobatic model aircraft in which all aerodynamic surfaces (except for the propeller
plus that/those surface/s used to control the flight path) remain fixed during flight.


4.2.2. Characteristics of an Aerobatic Model Aircraft

a) Maximum total flying weight (excluding fuel) ... 3.5 kg
b) Maximum wingspan (overall) ........................... 2.0 m
c) Maximum length (overall) ................................ 2.0 m

d) Permitted power sources shall include any power except rocket motors. Piston engine/s shall be
subject to a total swept volume limitation of 15 cm3. Electric power shall be limited to a maximum noload
voltage of 42 volts. Gas turbine engines shall be limited to 10 N static thrust.

i) A suitable silencer must be used on all piston engines.

ii) The noise limit set out at paragraph 4.2.6 c) shall apply to all power sources.

e) Wireless remote control (electrical, optical, or any other) of any control function of, and/or of any
system in the model aircraft shall not be permitted.

f) The following exceptions to rule 1.3.2 of Section 4C of Volume ABR are allowed.

i) Other controls may include, but are not limited to: landing gear operation and built-in engine
starters. Such functions may be controlled by the pilot only via line/lines, or may function
completely automatically. The frequency of any electromagnetic pulses transmitted through
wires/cables to the model aircraft shall not exceed 30 kHz.

ii) For piston engines (including "Wankel" rotary types), no outside control of the engine/s in-flight
power output shall be permitted whether or not such control is direct to the engine/s or via
propeller/s with variable pitch. For the purposes of this paragraph, the term "in-flight" shall mean
the time between the release of the model aircraft for the Take-off Manoeuvre and the end of the
Landing Manoeuvre. Active or dynamic automatic power output control based on flight parameters
such as, but not limited to, shall also not be permitted: model aircraft speed; angular speed;
centrifugal force; line pull; flying height; or any combination or derivation thereof. However, if not
used for the purpose of active power and/or throttle control, the following shall be permitted:

a) Passive or static devices controlling rate of fuel flow or fuel pressure (for example "uniflow" fuel
tanks).

b) Passive or static exhaust systems (for example tuned-length exhaust pipes to control engine
rpm).

c) Provided they are used only to end a flight, the use of engine/s shut-off systems, either
operated by the pilot or functioning fully automatically, shall be permitted, subject to the
restriction at paragraph e) above.

g) For power sources other than piston engines, engine power controlling systems, whether pilot operated
or automatic, shall be permitted.




Kim Doherty
Member,
FAI F2 Subcommittee

[Alan Hahn]

If I understand that last rule (under "g"), it sounds like governor mode (or almost any other mode you could thing of) is allowed on electrics. Seems to give some advantage to an electric setup

[Paul Smith]

If I understand that last rule (under "g"), it sounds like governor mode (or almost any other mode you could thing of) is allowed on electrics. Seems to give some advantage to an electric setup

Very true,,, the rules are skewed in favor of electrics.

On the other hand, they still let liquid-fueled models be weighed, and calculate pull test, dry.   Clearly both unsafe and prejudiced against battery-powered toys.

[Trostle]

[b]YES, effective 1st January 2007.[/b]

Also, please note that the FAI requires only 1.5, not 2 laps between manouvers.  This makes 7 minutes a bit easier to achieve.   Not on every manonver, just on some: reverse wingover, inside loops, inverted, overhead eight, and cloverleaf, a potential of 25 to 30 seconds here.

Yes, the FAI rules require only 1.5 laps between maneuvers.  The wording from the F2B rules:

"Every competitior shall leave at least 1 1/2 laps plus the recommended entry and exit procedure detailed for each manoeuvre to create a pause periord between the end of one manoeuvre and the start of the next."  Essentially, the only times that the 1 1/2 lap allowance applies is between the Hourglass and the Overhead Eights and possibly the start of the Reverse Wing-over depending on where the Take-off is started.  Following the wording in the rules, when performing the "recommended entry and exit procedure detailed for each manoeuvre", there will be essentially two laps between each manoeuvre except between the Hourglass and the Overhead Eights and possibly between the judged Take-off/level flight and the Rreverse Wing-over (again, the start of the Reverse Wing-over depends on the location where the Take-off begins).

Now, there will be people who can develop scenarios or even fly a pattern where "maneuvres" are flown in peculiar locations in the hemisphere or initiate "manoeuvres" to actually perform only 1 1/2 laps between those "maneuvres".  This will normally result in at least some of those "manoeuvres" being flown in a location to give the judges a less than optimum vantage point to accurately score the "manoeuvre" and the score would likely suffer as judges normally do not give a good score for something they cannot see.  Furthermore, if peculiar entries for certain maneuvers that are essentially outside the "norm" of what a judge expects to see, the flyer is showing more how clever he is rather than trying to demostrate to the judge how well he can fly the pattern.  Some judges may resent that and the score might reflect that resentment.

There may be people here that might want to argue this, but I can assure you that at the World Championships, if the letter of this rule is not followed, even for the suggested "inside loops, inverted, and cloverleaf" and the requisite number of laps are not flown prior to the start of a "manoeuvre", as defined above, the "judges shall award a mark 0 (zero)..." for that "manoeuvre".   And there is little need to even make the judges wonder about the appropriate number of laps between Level Flight and the Reverse Wing-over.

Unless an extremely slow lap time of more than 6.5 seconds is flown throughout the pattern, the 7 minute limit for F2B is plenty of time to complete the pattern.  If a pilot chooses to fly such a slow pattern, there is still time to complete the pattern in 7 minutes, but a timer to shut the motor down within the limit might be desirable.

Keith Trostle

[Trostle]

If I understand that last rule (under "g"), it sounds like governor mode (or almost any other mode you could thing of) is allowed on electrics. Seems to give some advantage to an electric setup

As Paul Smith indicated, active motor controls are allowed for electrics in F2B but are not allowed for piston engines other than the use of tank plumbing and/or tuned pipes to affect how the engine runs.

The F2B rules makers are very much aware that this situation gives an advantage to the electrics.  It will be interesting to see how long it will take for the electrics to have a practical and decided advantage over piston engines because of the way the rules are now written.

One thing that operators of electrics in F2B will need to employ are prop brakes.  These are necessary so that judges will know that the motor has stopped prior to judging the one full lap from the start of the landing at the height of 1.5 meters.  Operation of the brake can be initiated at the time the motor is shut down.

The technology is available.  The FF guys use brakes to stop the prop in less than a second after their engines are turning more than 30,000 rpm.

A solution to this matter would be to eliminate or revise the "1 full-gliding lap (power off condition)" rule.

Keith Trostle

[Kim Doherty]

Very true,,, the rules are skewed in favor of electrics.

On the other hand, they still let liquid-fueled models be weighed, and calculate pull test, dry.   Clearly both unsafe and prejudiced against battery-powered toys.

Paul, Alan,

The rules are most definitely skewed in favour of electric power and perhaps rightly so. Losing flying sites is an issue. Transport of flammable goods is an issue. Safety and ease of use is an issue. Other model aviation categories were passing us by. The technology employed in Control line was getting stale. Electric power provides a whole new world of opportunities for those that fly control line.

Keith Said: "The F2B rules makers are very much aware that this situation gives an advantage to the electrics.  It will be interesting to see how long it will take for the electrics to have a practical and decided advantage over piston engines because of the way the rules are now written."

I think we may already be at that point. We just did not know enough about how to use them properly this past summer. Look for some interesting results at the U.S. Nats this summer!

As to pull tests, electric planes are weighed without the battery. My plane was the first electric to be processed at the W/C's last summer and there was no question about whether the battery should be included or not. The only thing I was asked to do was to prove that my battery packs were not more than 42 volts. A quick demonstration with the Fluke meter and that was that.

Electric power is not just a blip on the radar screen. It is a fully loaded freight train comming at you with no brakes!

Kim.
 

[PatRobinson]

I went to the PAMP site and read the FAI rules several months ago and when I read this section I had several questions occur to me so I thought I would ask here.  The obvious effect of these rules is to suppress inovation in stunt
but organizations like the FAI have a train of logic and organizational goals that propel them to shape their rules.

My question is "What was the thinking that moved the FAI to enact these rules?"   Guys. this is an honest inquiry for information so p-lease  don't
make this political in any way at all.  Please don't do that. This question is
about logic & not feelings. For example, if it is the FAI's "goal" is to keep stunt a more traditional event then that is a legitimate objective for an organization and its members to pursue. "Sparky" works hard to keep us free
of all that nonsense and this site has many bright  guys who are fully capable of having a logical exchange of ideas.  I really just want to understand.
                                                                       Respectfully,
                                                                        Pat Robinson
a logical exchange of ideas

[Paul Smith]

In any motor sport, innovation needs to be "suppressed" to a certain point, otherwise it will evolve into something completely different. 

They put lids on both NASCAR and USAC racing, otherwise people would be getting killed every race. Fans and owners understand that.

Cars and motorcycles are faster than horses, but they still have horse racing.

In model airplane events, technology needs to be contained to point where cost and performance don't go beyond people's means.  We've had a "200 MPH speed limit" in CL speed for 40 years, enforced by automatic increases in line size.

Numerous modeling events have failed to contain technology, and now they're preserved by 3 or 4 flyers.   Stunt's success is largely due to it's ablity to keep game the same. 

[Kim Doherty]

I went to the PAMP site and read the FAI rules several months ago and when I read this section I had several questions occur to me so I thought I would ask here.  The obvious effect of these rules is to suppress inovation in stunt but organizations like the FAI have a train of logic and organizational goals that propel them to shape their rules.

My question is "What was the thinking that moved the FAI to enact these rules?"    For example, if it is the FAI's "goal" is to keep stunt a more traditional event then that is a legitimate objective for an organization and its members to pursue.                                              Respectfully,
                                                                        Pat Robinson

Pat,

As someone who has flown under FAI rules for a long time let me assure you that the new rule amendments do not in any way "suppress innovation". Quite the contrary, IMHO the rule changes foster better contest formats (multiple circles - fewer judges per circle), more creative power trains (electric) and equalize power advantages for IC engines (4 stroke displ= 2 stroke displ). Very few of the rules that you have read are new as a whole. They have simply been tweaked from their former wording. The FAI in no way wishes to keep stunt as a traditional event however as Paul rightly states, there must be controls on just how far you can go or there would be no purpose in holding a contest. Perhaps if you could be more specific with respect to which rules you are refering to and share your views as to why you feel innovation is being suppressed and just how these rules are keeping stunt in a traditional rut I and others could try to address your concerns.

Kim.

[Mike Palko]

As to pull tests, electric planes are weighed without the battery. My plane was the first electric to be processed at the W/C's last summer and there was no question about whether the battery should be included or not. The only thing I was asked to do was to prove that my battery packs were not more than 42 volts. A quick demonstration with the Fluke meter and that was that.

Electric power is not just a blip on the radar screen. It is a fully loaded freight train comming at you with no brakes!

Kim.
 

 

Kim that is interesting that they weigh the model w/o the battery. Is it the same for determining line diameter? .015 for models less than 48oz and .018 for models more than 48oz. I always assumed it included the battery.

Electric may present an advantage, but pilot skill is the ultimate advantage!! IC isn't going away any time soon. If electric does nothing for the hobby other than saving a few flying fields it is fine by me. My club field is in jeopardy for several reasons, noise being one of them. 

I am also looking forward to the NATS this year!!! Tradition does get old after a while, we can fly OTS or Classic if we like tradition. I think we should be able to push precision aerobatics to new limits each year (within reason). I don't necessarily mean power systems either. It's what keeps the sport interesting!!

I do agree with cost being a big problem and in turn limiting the number of people who can compete. Rules changes may have to be made more often to help prevent this.

[Trostle]

 

Kim that is interesting that they weigh the model w/o the battery. Is it the same for determining line diameter? .015 for models less than 48oz and .018 for models more than 48oz. I always assumed it included the battery.

(clip)

Mike,

There are several things here that might need some clarification.

First, the FAI F2B rules that Kim refers to do not specify line diameters.  The FAI pull test is 10 times the model weight, whether electric or IC.

Second, our AMA rules have been changed to be effective as of this January 1.  As before, the pull test for electrics will be based on model weight.  However, the line sizes have been changed to be more in line with "equivalent" size/weight IC models.  Before this change, the electrics were at a disadvantage when compared to similar size and power IC models except for heavier electric models where anything more than three pounds could be flown on any .018 lines.  (There are a couple of people in Texas who do not fly electrics, but feel these changes were not good.)

Up to 24 ounces, electrics can use .008 solids, .008 cables
24 to 40 ounces, electrics can use .010 solids, .012 cables.
40 to 64 ounces, electrics can use .012 solids, .015 cables.
64 to 75 ounces, electrics can use .014 solids, .018 cables
75 to 123 ounces, electrics can use .018 solids, .021 cables.

The way the revised AMA rules read is that the "Electric powered measured model weight includes weight of batteries."

Since electrics are now allowed in our AMA CLPA event, there is no longer a separate electric  CLPA event #608.  The AMA CLPA rules incorporate the new line sizes for electrics in line size and pull test chart

Keith Trostle

[Peter Germann]

I went to the PAMP site and read the FAI rules several months ago and when I read this section I had several questions occur to me so I thought I would ask here.  The obvious effect of these rules is to suppress inovation in stunt
but organizations like the FAI have a train of logic and organizational goals that propel them to shape their rules.

My question is "What was the thinking that moved the FAI to enact these rules?"   Guys. this is an honest inquiry for information so p-lease  don't
make this political in any way at all.  Please don't do that. This question is
about logic & not feelings. For example, if it is the FAI's "goal" is to keep stunt a more traditional event then that is a legitimate objective for an organization and its members to pursue. "Sparky" works hard to keep us free
of all that nonsense and this site has many bright  guys who are fully capable of having a logical exchange of ideas.  I really just want to understand.
                                                                       Respectfully,
                                                                        Pat Robinson
a logical exchange of ideas

F2B; Electric advantage over IC?

As mentioned in this forum before, the F2B rule makers are in fact aware of the technical advantage eventually resulting from the use of electric power in control line stunt.

In-flight adaptive (automatic and situation depending) power control for electric motors is probably a prerequisite for successful competition flying on top level. Once demonstrated as being competitive, or even superior, by the “opinion leaders” over a certain time and in various parts of the world, this technology will become available. As “winner” technology always filters down rather quickly, flying electric stunt may well become the generally adopted State-of-the-Art within just a couple of years. It is the purpose of the current F2B rule to promote and support electric stunters, which will play an important role when it comes to keep flying sites or to open now ones.

We, the F2B Work Group, do believe that the potential disadvantage of IC power is an affordable price to pay for to increase the public visibility and awareness of control line flying in general. Our  community now has a chance to bring c/l back from the remote sites to where it came from. This is a unique opportunity, definitely worthwhile an extraordinary effort.

The F2B Work Group takes full responsibility for the set of rules and observes the evolution very carefully. It will not hesitate to correct unfair situations, should they arrive.

Peter D. Germann
CIAM F2 Subcommittee
F2B Work Group Coordinator

[Paul Smith]

I just downloaded and printed a copy of the latest FAI Rules, took half an ink cartridge.

It says: Maximum weight 3.5 kilos (excluding fuel), in 4.2.2

Line Test 4.4.4: ,,,"weight of the model without fuel.."

It never actually says, without batteries.

An Internal Combustion model has a fuel tank, into which liquid fuel is added.
An Electric model has has a battery pack (which includes wires, plugs, insulation, and storage media) into which is an electric charge is stored.

If I were the judge, I would allow models to be weighed without the fuel, either liquid or electric, but include the fuel storage device.

To do otherwise would understate the mass of an IC model by 5% and an electric model by 50%.

[Kim Doherty]

It never actually says, without batteries.

An Internal Combustion model has a fuel tank, into which liquid fuel is added.
An Electric model has has a battery pack (which includes wires, plugs, insulation, and storage media) into which is an electric charge is stored.

If I were the judge, I would allow models to be weighed without the fuel, either liquid or electric, but include the fuel storage device.

To do otherwise would understate the mass of an IC model by 5% and an electric model by 50%.

Paul,

As a modeler flying under AMA rules, I would expect that you would weigh the plane with the battery since this is what your rule book requires.

As a modeler flying under FAI rules at a World Championship with more than thirty countries present, (including the U.S.A) I flew an electric powered model and was not required to include the battery for weighing. No protests were filed. It was public knowledge and obviously benefited one pilot from your own country.

If you think that the FAI is asleep at the switch, you would be dead wrong. The discussions revolving around the logistics involved in permitting electric powered models to compete in FAI competition were extensive.

Your stated figures of understating the mass of an IC model by 5% and an electric model by 50% are simply not even close. In a 57 ounce IC powered model with 7 ounces of fuel, the fuel represents 12% of the mass. In an electric model the battery would likely account for about 23% of the total mass.

As has been stated several times in this thread, there are some small intentional advantages to embracing electric flight designed to encourage modelers to adopt this technology. Better to go now willingly than to be forced by edict to do so later. Also better to have a place to fly than not!

Kim.

[PatRobinson]

Guys I want to thank you for your thoughtful answers and input to my question.    Kim, to specifically answer your question about what I mean't
by suppress inovation i will provide a couple of examples :
1.A flier is experimenting with a high aspect wing on a larger modern size airplane and he may end up exceeding 2 meters in span.
2. A flier is trying out a heavier than usual engine in pursuit of a certain performance goal and even after he shortening the nose he may need to lengthen the fuselage to balance this engine without adding a lot of lead in the tail  but he may exceed the rule book  fuselage length.
3. "Windy U" brought infra-red controls to stunt to control the engine and/or
control retracts. I liked the idea because you could save your engines from
lean runs if nothing else.  The FAI ban seems to have squashed acceptance
from flyers who might have tried it out.

I think Peter's explanation about encouraging electric airplanes in order to open up more flying sites and hopefully recruit more particpants because
they were exposed to the hobby at these added flying sites is a perfectly
logical and legitimate goal for an organization like the FAI. It is also logical
and valid to provide disincentives to IC powered airplanes in pursuit of those organizational goals. I also clearly understand airplane weight limits
because it is a safety issue but I'm not sure of the reasons for wingspan and fuselage length limitations but I'm sure there is a train of logic that I can't see. If anyone can clarify it for me I would appreciate it.

In regards to my use of an hypothetical example of "keeping stunt more traditional" it was not my intent to say that I think that this is the reason
for the rules but it was only a "made-up example"of how to keep the discussion logical and to not devolve into something less than a valid discussion of ideas. Sorry if I wasn't clear about this point.

Gentlemen, this thread is the way net discussions should be handled.
There is no negativity that distracts from a clear exchange of ideas and that negative stuff is just tiring and boring.  My compliments to you all and I thank you for helping me understand the thought processes more clearly.
                                                                     Respectfully.
                                                                      Pat Robinson

not devolve  

[Kim Doherty]

Guys I want to thank you for your thoughtful answers and input to my question.    Kim, to specifically answer your question about what I mean't
by suppress inovation i will provide a couple of examples :
1.A flier is experimenting with a high aspect wing on a larger modern size airplane and he may end up exceeding 2 meters in span.
2. A flier is trying out a heavier than usual engine in pursuit of a certain performance goal and even after he shortening the nose he may need to lengthen the fuselage to balance this engine without adding a lot of lead in the tail  but he may exceed the rule book  fuselage length.
3. "Windy U" brought infra-red controls to stunt to control the engine and/or
control retracts. I liked the idea because you could save your engines from
lean runs if nothing else.  The FAI ban seems to have squashed acceptance
from flyers who might have tried it out.

I also clearly understand airplane weight limits
because it is a safety issue but I'm not sure of the reasons for wingspan and fuselage length limitations but I'm sure there is a train of logic that I can't see. If anyone can clarify it for me I would appreciate it.

Pat,

No one and certainly not the FAI has ever tried to suppress ANY type of innovation related to control line model flying. I have seen Windy fly his Z-tron controlled plane and it was amazing! If a person wants to experiment with 4 metre wings and can do so safely and not void his associations insurance policy or code of conduct then go for it.

What we are talking about here is the administration of contests up to and including a World Championship. Without controls (rules) we would simply have a technology demonstration and not an equitable contest. As Paul has stated above:

"In model airplane events, technology needs to be contained to the point where cost and performance don't go beyond people's means.  We've had a "200 MPH speed limit" in CL speed for 40 years, enforced by automatic increases in line size.

Numerous modeling events have failed to contain technology, and now they're preserved by 3 or 4 flyers.   Stunt's success is largely due to it's ability to keep game the same. "

While we could certainly throw the rules wide open our flying sites may not be able to accommodate the new models. No one is building new control line flying sites anymore. We must operate within the physical limitations of what we have. Some sites are enclosed by wire fences (Kiev), some require temporary safety fencing to separate two circles thus limiting the absolute flying diameter (Sebnitz -  ask Dave Fitz.). If the organizers of World competitions had to accommodate all models without restriction, no one would volunteer to host the contest.

Would one hundred people spend thousands of dollars each to travel half way around the world to compete in a contest where the only rule was that there really are no rules? I doubt it. I wouldn't.

Should someone want to organize a contest where unlimited span wings with unlimited length fuselages and Ztron IR controls were permitted, there is nothing stopping them. I would even encourage it. Were it to gain the stature of the FAI F2B World Champs I would stand and applaud their efforts.

Kim.

[PatRobinson]

Kim,
I started this inquiry because I just wanted to understand the logic behind these few points of the FAI rules and you and Peter have done an outstanding job of bringing clarity and understanding and I thank you.

I want to apologize if the word "suppress" seemed to be a negative critcism of FAI because that was not my intent, I'm not sure which word to substitute.
I'm not advocating a point of view, just seeking understanding.

I fully agree with your concerns about flying site limits and in fact I would think that it would be the responsibility of a flier of a longer wing to shorten
his lines to conform to the flying site and not the flying site conforming to an out of the norm airplane.  Your concerns are well taken.

I also fully agree with your concerns to avoid a "technlogical race" in stunt
that has harmed other events.  Changes should evolve at a measured pace that are inclusive to most participants and avoids excluding people simply because their hobby budget can't afford the latest and greatest "thing" that you must have to stay competitive.   This point of concern is also well taken.
I think responsible evolved change does allow progress but you must also protect the well being of the event while you do it. The rules makers are faced with balancing these concerns and also other goals like encouraging electric flight that Peter discussed. I can clearly understand this point.

Kim, I would like to reassure you that I would never advocate having a contest without rules. That would be unthinkable and unworkable.
I have helped run contests for 30 years which is a  demanding enough endeavor with clear rules and it is simply unthinkable without them.
My inquiry was limited to the narrow focus of 1. limits on airplane size and
2. limits on timers and infrared controls and etc. and that is all. I now have a much clearer understanding of the logic involved in these rules.

Kim. I live in the southern US and I will probably never be directly effected by FAI rules so I don't have any vested interest or agenda and I am not even advocating that anyone do anything,in fact I didn't even have a clear point of
view until I asked this question and you gentlemen were kind enough to answer it and enhance my understanding. 

Kim I would like to personally thank you and Peter and everyone else who have been gracious enough to share their perspective and knowledge with me.
                                                             Thankfully,
                                                           Pat Robinson

[Trostle]

(clip)

My inquiry was limited to the narrow focus of 1. limits on airplane size and
2. limits on timers and infrared controls and etc. and that is all. I now have a much clearer understanding of the logic involved in these rules.

(clip)
                                                             Thankfully,
                                                           Pat Robinson

Pat,

I think you are to be commended for the manner you asked your questions and to how you have expressed yourself after Kim and Peter provided their informative responses to your questions.

As to your comments above, I do not know if you feel that these two items remain answered or not.

I think Peter and Kim both explained the situation regarding the need to limit the size of the F2B models.  Many venues used world-wide are very restricted regarding space.  There becomes a safety factor at many of these locations if the model has a span in excess of 2 meters (over 78 inches).  There has been an increase in the size of our stunt models over the years, but there is very little evidence of models that start even approaching this limit.  As has been suggested, it is possible to experiment with really long span models, just not at a contest if the span/length exceeds those limits.  Besides, there really becomes a practical limit to the size of a model that can be flown and and presented as a competitive pattern when limited to the 70.8 f00t wire length (F2B rules).  Maybe there is an idea somewhere that might work very well for a model using something approaching these limits, but it has not surfaced to receive any attention.  There have been some very high aspect ratio designs appear from time to time, but my experience has been that such designs do not do well in turbulent and high wind conditions. 

The real purpose of my post here is to respond to your comment about limits on timers and infrared systems.  The comments below apply to the F2B rules.

First, there is currently no restriction on the use of timers.  Timers can be used to shut down the engine/motor and/or operate the landing gear or initiate an engine/motor starter.

Second, as you probably have already read, "Wireless remote control (electrical, optical or any other) of any control function of, and/or of any system in the model aircraft shall not be permitted."  This restriction is to eliminate the need for frequency control at a control line contest and to prevent the possibility of inadvertent signals, unintentional or otherwise, interrupting any official flight.  Now, I think an argument could be made in the future to allow an optical system (infrared or visible light) that is coded in a way such that there would be an almost statistical impossibility that interference or inadvertent signals could ever disrupt the flight of a model and that transmitters would not have to be impounded.  This is something for the rules makers to consider in the future. 

Keith Trostle

[PatRobinson]

Thank you Keith,
As usual, you are one very clear, precise ,cogent and informative gentleman and your input is welcome and helpful.  I guess the only thing I'm uncertain
of is the issue of fuselage length. The trend to bigger 2 stroke and 4 stroke
engines also means heavier engines that may at some point need a longer fuselage to balance them without using a bunch of lead in the tail. Sometimes
only a couple inches is enough to do the job. Now most of us aren't going to
to use a 78" fuselage but with bigger engines the prospect of a"Sweeper" size
really big plane becomes more feasible and then the 2 meter limit might come into play.  We Americans have an affinity for "bigger is better" so who knows what might turn up at a future flying circle. I guess we will  just have to cross that bridge when we come to it.  Any new big airplane would have to prove it's worth in competition before it it involved FAI rules. The use of
multiple engines could also lead to longer wingspans like the "L.A.Heat" which I think slightly exceeds rule limits but it would seem likely that a multiple engine plane would probably not exceed fuselage length with judicious engine selection that considers weight.
  Anyway Keith I want to thank you very much for your input it has been very helpful and informative it meets your usual high standard of excellence that you provide in all your posts. 
                                                            Thankfully,
                                                            Pat Robinson

[Dean Pappas]

Hello All,
It is so good to see F2 committee members involved in these forum discussions.
I wish to applaud the F2 committe for its clear thinking and visionary sense, in regard to the rules changes that facilitate electric Stunt. The event will benefit in both the short and long term.

Thank You,
Dean Pappas