6^th June 2001

 

Please find attached the first issue(s) to be dealt within the F2B Rules Rewrite.

Results need to be collated and returned to Andy Sweetland  by early July, so if you would like to contribute any comments / opinions/ suggestions etc could you please return these  to me as early as possible. 

Many thanks,

Joan McIntyre.

 

E-mail your response to:  [email protected]

 

 ( My apologies to those of you who did not receive the background notes. We are endeavoring to circulate the proposed changes as widely as possible and to have as much input from the Stunt community as we can.).

 

The next topic will relate to:-

(i) Contest use of grass circles and associated changes ( minor ) in two manoeuvres ( Take Off and Landing.)

(ii) Contest weather and safety.

(iii) Scoring zero in an official flight.

(iv) Reflights.

 

TOPICS GROUP ONE – JUNE 2001

1.       REFERENCES AND SOURCES:

1.       RESPONSE DEADLINE:

ALL ANSWERS BY 7^th JULY PLEASE

(You don’t need to answer if you and your contacts have no comments and/or suggestions – for any nation not answering we‘ll just assume that no answer means "we agree")

2.       TOPICS IN THIS GROUP:

A) New general definition of C/L models; B) New definition and specification of F2B models; C) New pull test; D) New noise limit and testing procedure; E) Use of electric, etc motor starting equipment.

4.       THE TOPICS, A through E:

Below you will find introductory info from Peter and I (the reasoning, etc) for each topic, followed by our proposals for fixing "the problem". Usually these proposals are shown by including an extract from our "1st Draft New F2B Rules & JG" document:

A.       New model definition for all C/L (F2):

When you read the current FAI Sporting Code (Section IV, Section 4C, Model Aircraft, Part One, "General Regulations for Model Aircraft", General Section, para 1.3.2) you will see a somewhat out-dated definition that apparently should still apply to all FAI C/L contest models today. Not only does that definition not reflect current FAI contest practice in a number of areas, but also, as presently written, it would prevent us making the changes that we think are needed in the F2B model definition and specification. But to change that general model definition will obviously need approval by all F2 people, not just us "Stunt grunts". For this reason, Peter and I have prepared a special single page paper. It is copied below for your comment. After we have had your comments, and when the Final Draft New F2B Rules" is finished, we will circulate that paper to all the CIAM F2 Subcommittee members for their comments and agreement. But first come your comments. Please read the short paper below, then move straight on to item B) below that (they are linked in terms of subject matter).

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The following extract from the FAI Sporting Code Section IV, Section 4C, Model Aircraft, Part One, "General Regulations for Model Aircraft" should also considered when re-writing the F2B rules themselves:

QUOTE:

1.3.2 Category F2 - Control Line Circular Flight

This is a flight during which the model aircraft is manoeuvred by control surfaces in attitude and altitude by the pilot on the ground by means of one or more inextensible wires or cables directly connected to the model aircraft. Devices in which the control wires or cables are held in the hand or connected to a central pivot may be used. No other means of controlling the model or the engine may be employed during take off and flight except that exercised by the pilot through the line or lines.

UNQUOTE:

As one of the goals of the F2B rules re-write is to allow for future technical development (to give just 2 possible examples: i) the use of electric power; ii) "opening" the rules to allow for the use of throttles, thereby making it possible to use more commonly available RC motors - which are often cheaper and sometimes quieter than specialist F2B motors), we recommend the following revisions to 1.3.2:

Suggested Revision For 1.3.2 Category F2 - Control Line Circular Flight

Control Line circular flight uses powered model aircraft which must be permanently attached to two or more non-extensible wires or cables during flight. Primary control functions (that is: controlling the height and attitude of the model’s flight) must be performed by the manual manipulation of a control handle held by a pilot located on the ground at the centre of the model's Flight Circle.

Control of secondary functions (which may include, but which are not limited to, control of engine/s, landing gear, landing flaps), may be accomplished by mechanical, electrical, or optical means activated by the pilot through the wires/cables, or may function completely automatically. No wireless remote control of either primary or secondary control functions is permitted.

Any additional provisions detailed within the regulations specific to each class for Control Line model aircraft (F2A, F2B, F2C, F2D, F4B) shall also be permitted.

Reasons for the proposed changes:

1.        The current FAI rule 1.3.2 is not entirely clear and definitive in relation to actual C/L practice when considering all 5 FAI classes as they are actually flown today. Examples of lack of clarity when considered against present F2B practice are the common use of uniflow fuel tanks (to "regulate" fuel pressure); or tuned-length exhaust pipes (to govern engine rpm). These could be regarded as "illegal" under the present rules (QUOTE from the present 1.3.2: No other means of controlling the model or the engine may be employed during take off and flight except that exercised by the pilot through the line or lines. UNQUOTE).

2.        Regarding future technical development, all 5 FAI C/L contest classes may be considered as being relatively "simple and un-complicated" (at least as far as primary control is concerned). This is something which many active contestants applaud, but which some do decry as stifling technical development. Levels of participation in all FAI C/L classes today are generally such that it is essential to retain the interest of both groups, so the wording above has been deliberately framed to cater for both groups, but without forcing change/more complexity as the only possible route to future contest success.

3.        It should also be noted that the reason for specifically prohibiting "wireless control" above is to prevent C/L being faced with the frequency clashes/transmitter control requirements experienced by the RC classes. It should be added that the term "wireless control" rather than "radio control " is used above quite deliberately. This is because systems using optical or sound impulses (for example) also exist, and such systems can also suffer from similar frequency conflict and jamming problems to those affecting RC.

Overall, the above should ensure continued FAI C/L contest participation by both the "keep it simple" and the "complexity is more interesting" groups, and we feel that the proposed re-wording of 1.3.2 above, when read in conjunction with the proposed revision to 4.2.2 (the F2B Model Definition & Specification), does meet all the goals set out above.

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A.       A new F2B model definition and specification:

The reasons for a new Stunt model definition and specification for FAI contests are, 1^st, we don’t want to prevent progress (electric power, and large, slow-turning, quiet i/c engines are 2 examples). That means having a new approach (no engine capacity limit), i.e. no more of the FAI 10cc limit, and the future limit would be "only" the overall FAI Model Aircraft limit (250cc). That may seem "extreme" at first sight, but why should F2B be different to all the other classes, it’s not a performance event like F2A or F2C is it? So as above, we can now "open" the way for big, slow-revving motors, but the effect of the new model weight limit we propose (3.5 Kgs), and the use of the existing FAI 21.5 metres line length limit would both actually insert a practical ceiling onto how big F2B engines would be in future – but without restricting those who wish to experiment. Not only would that bring the above benefits for F2B itself, but it would also considerably simplify Model Processing at World and Continental Championships. Below is an extract from "1^st Draft New F2B Rules & JG" where the proposed new F2B model definition and specification is detailed in full:

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1.       Model Definition and Specification

Powered Control Line model aircraft in which all aerodynamic surfaces except the control surface/s and propeller/s remain fixed in flight (refer to the FAI Sporting Code Section IV, Section 4C Model Aircraft, Part One, General Regulations, paragraph 1.3.2). The following specification limits shall apply:

a.        Maximum total flying weight (excluding fuel) 3.5 kg (7lbs 11ozs), plus/minus 1%

b.       Maximum wingspan overall 2.0 metres (6ft 6ins)

c.        Maximum length overall 2.0 metres (6ft 6ins)

d.       Permitted power source/s shall include any suitable powerplant/s except rocket motors which require solid or gaseous or liquefied fuels. Piston engine/s shall be subject to the same total swept volume limitation as per the FAI Sporting Code Section IV, Volume 4BR, Section 4C, Part One, rule 1.2, page 41, 5^th paragraph (maximum 250 cm³ - 15³/₄ ins³). Electric motors shall also be limited as per the above reference, rule 1.2, 6^th paragraph (maximum no-load voltage 42 volts).

e.        A noise limit of not exceeding 94 dB(A) shall apply to all types of motors. The noise level shall be checked in accordance with the procedure set out at 4.2.4.2.8.

f.         Minimum length of control line/s shall be 15.0 metres (49ft), maximum length 21.5 metres (70ft 6ins), to be measured from the centre-line of the grip of the control handle to the centre-line of the propeller. Where multiple propellers are employed, their axis of symmetry shall be taken as the reference for measurement.

g.       Models must Take-off from and land on the Flight Circles provided by contest organisers.

h.       Paragraph B3.1 of the FAI Sporting Code Section IV, Volume 4BR, Section 4B, page 28 (the builder of the model rule) shall not apply to Class F2B.

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SPACE FOR YOUR NATION’S COMMENTS ON TOPICS A AND B: (write as much – or as little - as you like, this box will expand to suit)

 

A.       The new pull test:

This is needed for 2 reasons. 1^st, it is arguable on "good scientific grounds" that the present pull test is not a safety check but could be a safety hazard. 2^nd, the above new F2B model definition and specification leads to a new pull test requirement, but this should be based on practical limits – i.e. model weight only, with no model size or engine displacement considerations. Here is the relevant extract from "1st Draft New F2B Rules & JG":

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6.       Testing of Control Lines at Contests

The 15 to 21.5 metre (49ft to 70ft 6ins) length of control lines of each contestant shall be checked at least once during every contest, as specified at 4.2.2, paragraph f). In addition, before every Attempt (refer 4.2.11) by every contestant, a test load of 10 times the total weight of the model without fuel shall be evenly and smoothly applied once only to the assembled control handle, lines, and model. The load used in this test shall be accurate within plus 0%/minus 10%.

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SPACE FOR YOUR NATION’S COMMENTS ON TOPIC C: (write as much – or as little - as you like, this box will expand to suit)

 

A.       New noise limit (and test):

All aeromodelling (and aeromodellers) face increasingly stringent noise restrictions. It is therefore simple good sense from the viewpoint of keeping existing flying sites, not to mention simply "good neighbour" relationships to make sure that we take the chance to move forward with other classes of aeromodelling in the area of noise. (This is another good reason for "opening" the new model specification to include electric power by the way). In addition, F2 generally is sometimes criticised by other modelling classes for having nil (or limited) noise restrictions. We all know that those criticisms don’t really apply to Stunt (or not often anyway), but in preparing the new rules we saw a good opportunity to apply the latest approach of some of the other aeromodelling classes. Here is the relevant extract from "1st Draft New F2B Rules & JG":

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8.       Noise Checking at Contests

a.        The noise level of any contestant’s model shall be measured by the contest organiser if the F2B CD, the Head Judge, or any other contest official or FAI jury member so requests. Such requests shall only be made if in the opinion of the person requesting the check the model concerned seems to be emitting a noise level higher than 94 dB(A), as specified at 4.2.2, paragraph e).

b.       If a noise measurement test is requested, the contest organiser shall use a calibrated noise meter positioned at 3.0 metres (10ft) from the centre line of the model, with the model placed on the ground over a concrete or tarmacadam surface immediately adjacent to the Flight Circle. With the motor running at full power, measurement shall be taken at 90 degrees to the flight path of the model, on the side of the model which is on the outside of the Flight Circle, at a position downwind from the model, with the noise meter microphone placed on a stand 30 cm (1ft) above the ground and in line with the motor/s. No noise reflecting object shall be nearer than 3.0 metres (10ft) from the model or from the noise meter microphone when measurement is taking place. If a concrete or tarmacadam surface is not available then the measurement may be taken over bare earth or very short grass, in which case the maximum noise level allowed shall be 92 dB(A).

c.        The noise test shall be carried out immediately after the last manoeuvre in the Official Flight (refer 4.2.10) during which the request for noise check was made, and apart from refuelling, no adjustment or modification of any kind shall be made to the model.

d.       If the model fails the noise test the contestant shall be informed immediately and the model shall be impounded by the contest organiser until a second official equipped with a second calibrated noise meter is brought to the Flight Circle area. The model shall then be re-tested by the second official using the second noise meter, as set out at paragraphs b) and c) above. If the model fails this second noise test then the contestant shall be scored 0 (zero) points for the Official Flight which preceded the noise tests.

e.        If failing the second noise test the model shall then be released to the contestant for modification and/or adjustment, but immediately upon completing the next Official Flight the contest organiser shall automatically subject the respective model to further noise test/s in accordance with the procedures set out at paragraphs b) through d) inclusive above.

f.         If passing the second noise test the model shall be considered to have passed the noise test.

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SPACE FOR YOUR NATION’S COMMENTS ON TOPIC D: (write as much – or as little - as you like, this box will expand to suit)

 

A.       Motor starting:

At least 2 attempts have been made in recent years to get the present F2B rules changed to allow the use of "non-manual" motor starting. These were based on safety considerations, but on each occasion the proposals have failed because some people were of the opinion that the safety case for using equipment such as electric starters was not sufficiently well-proven with today’s F2B motors – there are other reasons for getting fingers in props, and on at least some occasions, electric starting could make the problem worse. We feel that the proposed increase to engines of, potentially at least, quite a bit larger displacement than the present 10cc limit (that’s 0.61 cu ins) immediately negates any such arguments in future – we suspect that not many would still argue that starting, say, a 30cc petrol engine by hand was a safe proposition. Also, with today’s modern engines (which generally start much more readily than those of 50 years ago), it’s fair to say that today’s F2B event is no longer an engine starting competition, and there are other ways of defining the quality of each F2B contestant than just making him start his engine by hand. As a further point, we feel that the "mystique" of hand starting already tends to discourage some beginners who may be future F2B entrants.

There is no text extract to add here – this change was simply a matter of taking the existing rule and deleting the words "by hand" from the rule about starting the engine within 1 minute. Incidentally, we have retained the 1 minute rule within the new draft rules, because we see a need to continue to "encourage" the smooth flow of contestants, especially at major (Championship) contests and others with a large number of entries.

SPACE FOR YOUR NATION’S COMMENTS ON TOPIC E: (write as much – or as little - as you like, this box will expand to suit)

 

5.        ANSWERING PROCEDURES:

PLEASE REPLY TO: [email protected] 1.        Save this file under a new name by adding your country 3 letter FAI code at the front of the file name (e.g. for France, add "FRA" to the existing file name to get "FRATpcsGrp1.doc"). 2.        Distribute/copy/print the original file amongst your Stunt contacts as much as you wish. 3.        Collect and summarise the resulting inputs, adding them to your new (re-named) file copy in the relevant topic boxes as you see them above. (I have already set the "Track Changes" and colour commands in this file, and those commands should transfer when you save your new copy. That means that your changes will be marked in a different colour in the boxes when you return the new file to me). 4.        Return your re-named file comments to me by the date shown at 2. above. THANKS FOR YOUR CO-OPERATION, IT WILL MAKE MY PART OF THE JOB MUCH EASIER. Andy Sweetland, Zürich, 7th June 2001

 

 

(FAI web site downloading info below for those that need help)

 

 

 

 

 

 

 

 

 

DOWNLOADING DOCUMENTS FROM THE FAI WEB SITE For those not familiar with this, click on the http address shown in the box at the top of page 1, item a). From there scroll down the page until you come to the box section marked "DOWNLOAD SECTION 4 FROM THE WEB". Within that box, scroll on further down until you come to "Control Line Competitions", it’s the 3rd item down, listed under the Activity heading/"F2, 2035k" under the Volume heading. Then just click on either the blue "FAI" or "Belgium" links, and within a short you will see the download dialogue box appear on your screen. Simply enter the address within your own PC that you wish to store the document and within about 5 minutes the complete document will be on your own PC hard disk. Follow a similar procedure to the above for the document called "General rules for CIAM activities, Competitions and records, Volume ABR". The other document you will need, called "General Section" can be found by following the link to be found right at the top of the page you first entered (it’s called "General Section" and is marked in red).   If you do not already have the "Acrobat Reader" software installed on your PC, you will need it to read all the FAI rule book files. This is available as a free download – amongst other sources, you’ll find a link to get this download on the FAI web site itself. You’ll find the link on the page "Sporting Code Section 4" mentioned above (it’s the 1st item under the heading "Information & Guidelines" on that page). Just follow the instructions there.