SEN 1953

Table of Contents - SEN 1953

  1. help from Ian
  2.  FFTSC document
  3. UK proposal

Help From Ian



For info my article and list of free flight  proposals which was in FFn is
on FAI web site under free flight documents

The full agenda of proposals is not yet published , when it is it will
appear on the CIAM website under the tabs About Us - Meetings - 2015 -


Also note that the Sporting Code for 2015 has been published at

(go down the page to Sporting Code near the bottom of the list, and get the
general section Volume ABR and the Free Flight part Volume F1)


Ian Kaynes


Thanks for your help.



You can go to the FAI website and download the document is PDF form.  We decided that because of the importance of the documents we would include them here too.  Note that some of the formatting, including capitalization "lost" a bit in the translation.


Model performance and proposals for 2015

By Ian Kaynes, December 2014

The CIAM Free Flight Subcommittee always keeps model performance under review, but this has been brought into particular focus by the performance evident in the 2013 World Championships and 2014 European Championships. There is a mismatch between our model performance and the typical size of fields available and the competition format. This is shown by the 7 round flights leaving half the competitors with a full score, when flights of over 10 minutes are possible in flyoffs, and when timekeeping eyesight becomes a factor in flyoff results when there is any wind. The basic problems are thus the

-          number of flights needed to complete the competition because performance exceeds the maximums required in most rounds

-          the distances model fly are much larger than many flying fields - timekeeper eyesight can be a limiting factor.

The problem is what to do about this and how to reduce performance without immediately making existing models obsolete. A difficulty in making any more fundamental changes is the current CIAM rule change schedule whereby proposals are only accepted for the Plenary meeting in the year in which the World Championships are held and any proposals which are accepted become effective the following January. Thus proposals which have now been submitted will be discussed at the April 2015 Plenary meeting and if accepted become effective in January 2016. There is currently no possibility of delaying implementation in order to give more notice of changes which might make models obsolete.

An apparently simple model change is to increase the minimum weight. However, the effect of this would be reduced by developing new wing sections to suit the faster flight speed and use the additional weight for installing more complexity in the models, again making existing models obsolete in a short time. 

A fundamental option would be to change to the small classes (F1G F1H F1P) but this would represent a considerable break with tradition, render all models obsolete and so probably be even more unpopular than restrictions on the ABC models. Other possibilities for each class include the following.


This is the class which has probably seen the greatest increase in performance in the recent years. The zoom height obtained by LDA or flapper models doubles what used to be achieved as a launch height. Line length could be reduced to scale down the performance, but this is the type of change which expands the gap between expert and average competitor, and makes the zoom launch more important. Changes which reduce the zoom launch height could reduce the recent increase in performance. This might be done by ruling that the line cannot be released when launching, having a line strength limit – having a “fuse” in the line which would break at a specified tension, or increasing line drag via a minimum line diameter or a pennant with increased drag. Larger and nonporous pennants were tested by two members of the FFSC and found to reduce launch height but to make towing much less pleasant.

On the aircraft banning flaps would simplify some models but would not reduce performance significantly, just drive models to use LDA sections. A more fundamental limit would be to ban incidence changes of the tailplane, which would totally change launch concept. 


This is possibly the most difficult class on which to reduce performance, but probably also the class with least need of reduction. To reduce motor weight is the easy way, but this falls into the category of a change which increases the gulf between expert and average flyer. Banning delayed prop release or variable pitch props would simplify models but only reduce performance by a few percent. Flaps have not really demonstrated their value, but banning them now would remove another potential complexity before it has become widespread. Limiting the competitor to using only VIT or rudder – but not both – would reduce performance but would also make trimming harder and possibly less satisfactory.


There are several features on power model which contribute to performance, complexity, cost of models, and unreliability: .geared motors, flaps, folding wings. Reducing the motor run would be possible immediate change. Reducing motor air intake size with a maximum venture diameter (used in some other model categories) would be simple to implement but would need evaluation for what value of limit to set for F1C. Banning geared motors or the model simplifications would need to be on a longer timescale in view of the investment in current models. Banning folding and flapped wings would have the advantage of improving model reliability and possibly reducing the number of crashes, and that danger part of our consideration for F1C.

Organisation of flying

From a performance standpoint the F1A first round max could be brought into line with the other classes at 4 minutes. 

The concept of a working time could bring added pressure on finding lift during the rounds. At a championship a limit of 10 minutes could be applied from the time you have engaged a timekeeper, if you have not launched by the end of that time it is counted as an attempt. Each flight would thus be similar to a flyoff as regards the preparation and launch time. Easy to apply to F1B and F1C but rather harder for the flyer to know the time in F1A when towing, but similar to a flyoff in that regard.

This could be extended to a group flying concept where groups of competitors fly together in a limited time window, with some form of normalisation to allow for different weather conditions for each group.

If performance could be reduced a little or more extended maximum flights made, it would be possible to reduce the number of flights below seven. This would reduce the current marathon of a very long competition day for competitors and timekeepers.

Proposals for 2015

The following is a summary of the proposals submitted for changes to the Volume F1 of the

Sporting Code. Full details will be contained in the agenda for the April 2015 CIAM Plenary meeting.


Germany propose to ban variable geometry of variable wing area in the specifications of F1A, F1B, F1C, F1G F1H F1K F1P. The reasons are given as:

1       not too complex to build 

2       not too complex to handle

3       not too expensive

4       to give a newcomer a lot of fun and satisfaction from the beginning

5       to keep the gap between a good flyer and a high-end flyer limited

Poland propose reducing the F1A towline length from 50m to 40m in order to reduce the numbers of fly-offs. Austria propose reducing the F1A towline length from 50m to 35m. The reason is given as: “Performance of F1A models is too high for nowadays flying sites under nowadays rules. The reduction of towline length is a good means to reduce performance. “

United Kingdom propose:-

In F1A the towline diameter must be at least 1.75mm and the line must not be released by the competitor until after the model has been launched. 

In F1B the propeller must have been released before the model leaves the competitor’s hands.

In F1C the maximum motor run is reduced from 5 to 4 seconds.

These are one element of a proposed series of restrictions on F1A F1B and F1C postulated for future years. See the UK discussion document. 

Germany propose reducing the maximum weight of an F1B motor from 30g to 25g. This will reduce the height of the climb and it is suggested that glide time after the propeller has folded will be of the order of 200 to 220 seconds. This will reduce the numbers in the flyoff.

Austria propose a requirement that all F1C models must have RDT, in order to reduce the feasibility of accidents with physical injury to minimum. 

Austria also propose that the F1C standard fuel should use ethanol instead on methanol. Thi is said to offer the two advantages that performance is reduced about 20% without any design changes and toxic agents are no longer used. Germany also propose the same change, with similar reasons

Poland propose to reduce the F1C motor run from 5 seconds to 4 seconds, in order to reduce the numbers in the flyoffs.

The FFSC propose to ban flaps on the classes which have not yet started to use them: F1E, F1G, F1H, F1J, F1K , F1P. This is to eliminate the potential for added complexity in these classes. There was not a clear majority in favour of extending the ban to F1B and so that class is not included.

The USA propose to introduce the E36 class as new FAI class F1S, which proposal was made last year by the FFSC but then withdrawn for lack of support.



The FFSC propose to increase the maximum for F1A in the first round to 4 minutes. Poland also propose this change.

As another change of maximum for F1A F1B and F1C, the FFSC propose also using a 4 minute maximum for the last round if conditions allow. In addition the number of flights should be reduced from 7 to 5. This aims to reduce the marathon nature of flying 7 rounds before the flyoff, with this ease of reaching the flyoff offset by the increased difficulty of a second long maximum flight. The maximum duration is still subject to change according to conditions. A number of World Cup events are already flown to a 5 round format without any problems. 

The FFSC propose that the maximum first flyoff be increased to 6 minutes. The 5 minute flyoff represents only a small increase over the rounds and is often rather easy to achieve.

The FFSC propose a system for splitting flyoffs with 12 or more competitors into 2 groups. This would ease the organisational difficulty of large flyoffs which are always possible in good weather. These stretch the facilities to the extreme both in terms of the number of timekeepers and the number of starting positions required. The proposed scheme, a simplification of a system used in Finland, endeavours to balance the potential unfairness of different flying conditions for the two groups. It is possible that on some occasions (item 7) there may be another flyoff required which might not have happened without the group flyoff system. However, this is considered worthwhile for avoiding a final choice of winner based on the results within the different conditions of 2 group flyoffs. The flight times are used directly for ordering the people eliminating the people in the group flyoff irrespective of the different flying conditions. With another flyoff guaranteed by (7) this ordering will not determine the winners but just the lower places. The chance element of being in a group with good or bad air is no different to the starting position draw for F1B and F1C when good air goes past only one end of the starting line.

The proposal requests adding a new item (f) to the bottom of paragraph 3.1.8:-

If the number of competitors in a flyoff is 12 or more and is greater than 25% of the number of competitors in the competition, then the flyoff shall be split into two groups 

1)       The number of competitors in each group will be as closely as possible equal 

2)       Competitors are allocated a group and starting position by a single draw

3)       A flyoff is flown for each group according to the other regulations of 3.1.8

4)       The second group flyoff must be flown as soon as possible after the first group.

5)       From both groups all flyers who achieve the maximum duration proceed to the next round

6)       An equal number of flyers from each group may proceed to the next round by including competitors from one group those with the best flights below the maximum time, providing the flight times are at least 75% of the maximum.

7)       If the selections (5) and (6) result in fewer than 4 competitors proceeding to the next round, then the two competitors with the highest flight times in each of the groups will proceed to the next round.

8)       Competitors eliminated in group flyoffs will be classified with final placing according to time achieved in the group flyoff

UK Proposal



Lots of you will have seen the discussions on e-mail, chat rooms and social media about the proposals that the BMFA (the UK's NAC) has put up for presentation at the 2015 CIAM Plenary.


Many will say they're ridiculous but they've missed the point we need to be talking not about what we do next season but the season 5 years on from now. In other words we need a long-term plan.


When you see these proposals (there's a summary further on) you'll realise that they contain the ideas for a proper future - not yet another 'reactive' quick fix.  


The aim is to get more people involved in flying models in the FAI Free Flight Classes that aren't too complex or too expensive or beyond their building skills. What will still be needed from those people, whatever they fly, there will still be a lot of commitment. 


We’ve been thinking of a way to do all this without creating a new set of classes, but at the same time gradually reducing the impact of current technology. 


Some people have wondered whether a lot of today’s flyers would give up if there was a "ban" on current advanced technology models and of course the last thing we want is for any of today’s flyers to give up; we think there’s a way of having our cake and eating it.


We need to reduce the technology - content and impact - gradually. Not in a knee jerk one-season effort but over a five-year thought through plan that gives FAI model flying an assured future. What we need is more people flying and that flying needs to be more accessible. 


We need to remember all the factors that impact on our activity and take account of the real World.


The aim of the BMFA proposal is to begin this process. We believe that CIAM as a whole (a lot of this applies to all the disciplines - not just Free Flight) needs to consider the long term future for the FAI classes and this may well mean altering CIAM's legislative process to allow this to happen.



The premise for the rule changes

The UK holds it to be self-evident that the performance of F1 class Free Flight models has reached a level at which now exceeds sensible limits.


We believe CIAM should commit to a planned step change in performance reduction over a period of five years. The CIAM bureau should mandate the free flight subcommittee to take the appropriate action to create and implement the necessary changes.


Current F1 class models have become extremely effective in achieving the maximum times and Championships are now decided on the fly off. The numbers reaching the fly off are far too high a proportion of the entry. In the last two events some 50% of the entry made the cut. In addition to the management of the numbers we have the situation of models out flying the sites available to us, especially at fly off time when flights of 10 minutes may be required to achieve a result. We need a long-term plan to reduce performance, and hence flight times, without emasculating the event.


In addition we should seek to reduce complexity and thus the cost. The models should be brought closer to the reach of the competent and ambitious sportsman and reduce the need for commercial involvement.


The levels of performance reduction needed are in the order of 50%, to enable a meaningful competition with a round maximum of 2.30 and maximum model performance of no more than 4 minutes.


The change process will require firm management but must avoid the danger of killing enthusiasm for the discipline. We suggest that a programme of change should be staged over 5 years with final complete replacement of models at the end of that time.


The structure of CIAM has meant that in the past changes have been made to model specifications and organisation on a reactive rather than a proactive basis. The effect of this has been to drive the models into ever-greater complexity. Rather than being driven by events we believe that CIAM should change this approach and adopt a proactive plan in order to tackle the current issues. The suggestions are as follows:

The staging of change

Stage 1 - Reductions in performance without model changes – with effect from 2016.

These changes are to show that CIAM is serious in its ambition to take proactive control. Stage 2 - Elimination of devices/technologies that may require re-trimming of models but will not make complete airframes redundant – effective from 2018

Stage 3 - Changes that that will require completely new airframes and will deliver still-air times of no more than 4.0 minutes and enable round maximums to be reduced to 2.30. - Effective from 2020


In order to comply with CIAM procedures only stage 1 changes are tabled as specific proposals at this time. This paper is appended in order to show their position within the phasing of the overall plan.

Detailed rule changes
Stage 1 rule changes

This stage is for simple ideas that will limit the existing performance without a wholesale change to the specification. The existing models can still be flown but there are some limitations placed upon their performance.

        F1A. The diameter of the towline to be increased (specified as 1.75mm diameter) the drag will reduce the launch speed. The towline is not to be released on launch. The launcher final contact point to be within one metre of the end of the line. This will cut the launch impetus and thus the altitude gain.

        F1B. DPR prohibited – A two handed launching is required. This will cut the launch impetus and thus climb height.

        F1C. Cut the engine run to 4 seconds.

Stage 2 rule changes

This stage starts the changes to the model specification. The following “devices” to be prohibited and restrictions introduced. This would be in 3 years (January 2018) these changes can be made without making total model fleets immediately redundant.


o   Flaps to wings banned

o   Restrict tow movement to three functions being straight, circle and launch.

o   Release functions restrict to only launch and glide settings.


o   VP props banned

o   Flaps to wings banned

o   DPR prop start banned

o   Only a single timer function other than DT

o   Limit prop diameter to 500mm.

o   Discus launch banned


o   Geared engines banned

o   Flapped wings banned

o   Folding wings banned

o   VP props banned

Stage 3 rule changes

In 5 years (January 2020) further stages that will mean totally new aircraft. The limitations in stages 1 and 2 would be retained but in addition

Span limitation for all classesF1A 1.90 metres

        F1B 1.30 metres

        F1C 2.10 metres

Management of the event

        Reduce rounds to 5. The consistency of models means that in good conditions models will still max, the number of flights has a minimal impact. This change allows more time to organise the eventual fly off.

        Within rounds allow a 10-minute working time to launch after the commitment to fly.

        At final stage a reduction of the max to 150 seconds. There will be a sufficient reduction in performance from all the changes to make this a suitable challenge and reduce the size of the flying site size required.

The effect

We believe that the above will start the debate and bring the performance of the F1 classes under control. The changes will still provide exciting models.


Roger Morrell