Southampton Model Aeroplane Club

Established 1932

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F3A Flying - what’s it all about ?

F3A is the special interest section of the Flying Code for AEROBATICS, specifically aerobatics outdoors, with fixed wing planes.  (There are separate categories for aerobatics indoors, F3P, and aerobatics with helicopters, F3H, but we will not deal with them here).

So the idea is to fly specific manouevres which look as good as possible, and a judging panel will score the contestants, the highest score winning.

Now, obviously, big planes fly better than small planes, so there has to be a class definition, which  is that planes should be no larger than 2m in any direction, and should not weigh more than 5 Kg.  If electric they should not use a battery with more than 42 volts.

The result is that a Sebart 125 Wind S, as shown in the picture, is an ideal entry model.  It can be purchased and set up for about £1200 and is good enough to compete (but unlikely to win). The top fliers are using more advanced models which cost £5000 to £10000 so are only for the serious.    

So what aerobatics are we going to fly ?

The world of aerobatics (fullsize and model) uses a special notation, called the Aresti code, to write down what aeros are needed in what order.  The whole sequence is called an Aresti-diagram and an example is given here.

It may seem a bit obscure at first, but you soon get the hang of it - the plane flies along a line, solid for upright, dashed for inverted flight.  A loop is notated by a circle, a roll by an arrow.  Dashed and dotted denotes knife-edge flight.  

The aeros are carried out in front of the judges (in 2D) and the items are linked in the diagram by dotted lines, which take no space in real flight.  The rest you can guess.

Items are scored out of 10, multiplied by the difficulty factor (some are harder than others) and the whole added to the score.  Now to fly… see if you can do it !

F3A Competition News - Richard Sharman-20/09/17

As some of you will know I have been competing in the national aerobatic competitions for radio-controlled models for a few years.  The object is to make the plane perform accurate 2-dimensional patterns in the sky according to a pre-defined schedule.  It is a challenging aspect of model flying which requires a high degree of control, a steady nerve, and of course some occasional luck.  The plane I have been flying this year has been a BJ Etude, electric powered, model designed specifically for aerobatics (as in the picture).

Before we go too far, I should just mention that the competitions are rune by the GBR/CAA which is the specialist body of the BMFA for this activity.  They apply the rules defined by the international authority on flying competitions, the FAI.  There are a number of different levels: Clubman, Intermediate, Masters and International which you can work up through according to ability.  I am at the Masters level although there are two people who regularly fly at Beaulieu who are at international level.

In order to create a level playing field it is specified that the model must be less than 2 metres long and wide, and must weigh less that 5 Kg on take off.  If anything happens in the flight (such as a wheel falls off) the score is set to zero.  

The sequence of items to be flown at Masters level comprises 20 items, 17 of which are scored out of 10 by a panel of judges..  An item may be fairly simple (such as a loop, or a roll) or may be complex (such as a combination manoeuvre involving loops, rolls, snaps, stalls, spins and other factors).  Each item is rated according to difficulty by a K factor of 1 to 5 which multiplies the score to get a final score.  A typical schedule could add up to 500 points for a perfect flight.  The pilot with the highest score wins.  It's actually a lot more complicated in detail, but you get the general idea.

The first competition this year was on 23rd April at Stanstead where I came second in my class.  The second competition was on 14th May at Birmingham where I came first.  The third competition was on 11th June at Derby which I withdrew from as the forecast winds were 20mph gusting to 30mph. Some people did fly, but all had some difficulty in the blustery conditions.  The fourth competition was on 23rd July at Mansfield which I was not allowed to compete in as extra time was devoted to the question of the GB team selection for the forthcoming world championships in November which will be held in Argentina.

However, I did compete in the GBR/CAA national championships which were held at the new BMFA location of Buckminster on the 5th and 6th of August, again coming second as shown in the picture.

For a variety of reasons I was not able to go to the BMFA National championships which were held at RAF Barkston Heath on the 26/27/28th of August.

Finally, we were privileged to run a GBR/CAA meeting at Beaulieu on the 9th September, and it was pleasing to see some top fliers come to our local area and show everybody how it is really done.  The visitors were very complimentary about our flying site, albeit that there are no modern facilities available (bar, restaurant, casino, etc).  

You get an indication of the flight line from the picture here.  The meeting went very well, but owing to an unfortunate incident I was not able to score any points here.  

All the points scored go together to count towards a league table for each class, and generally those who took part in the most events do well in the league.  All the scores are normalised to make each event could equally.

A novelty this year was the introduction of an electronic scoring system.  In the past the judges called the scores as the planes flew, which were then written down by scribes, handed in to the context director who tabulated the results and posted a list of rankings.  This year the whole process was automated with scores being entered on tablets connected to a central scoring system so that rankings come up in real time on a large TV screen.  This certainly looked a lot more professional, although as with any new system there were a few teething problems at times.  The system was also used in the UK round of the World Cup which was held in Kent.