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    Austin

    By Austin, in BARCS,

    Our praise and thanks goes to Gary Binnie who undertaking the task of digitalizing the Soarer Magazines we used to send out to members on a monthly basis.
    If you click here you will be redirected to all the available issues so far. Feel free to view or download them.

    By Gary B, in Articles,

    It has been a while since I wrote an article for the website and I’m in the mood so here goes!
    Although I’m not a BMFA instructor I do teach club members occasionally using a buddy lead and give a limited amount of theory to help them understand how models fly (too much glazes their eyes over!).
    It is understandable that beginners have very little knowledge of the theory of flight but it is sometimes surprising that experienced model flyers also have a limited knowledge.
    In a former life I was a full-time gliding instructor as part of the Joint Services Adventurous Training organisation, we took soldiers, sailors and airmen with no prior flying experience and aimed to send them solo on aerotow after four or five days intensive coaching.

    If I was instructing (as opposed to running the course or flying the tugs and motor-gliders) I would be given a group of four people and ‘nurture’ them through the week. On the first day of the course they would all be flown in the motor-glider (Grob 109B) and given an hour instruction purely on the effects of controls with most of the course members being able to fly straight and level and carry out medium banked turns by the end of the lesson.
    The motor-glider lesson was often preceded by a short blackboard briefing and use of the hands to simulate aircraft movements!
    What we taught was quite basic but fundamental, particularly the standard terminology that we used, it also applies to model aircraft.
    So…what did we talk about? The very first lesson was ‘effects of controls’, quite simple and most people got this straight away. Text in speech marks was the standard ‘patter’ (in-flight commentary) that we used, key words are in bold.

    Primary effects:
    Elevator
    ‘The effect of the elevator is to control the aircraft in pitch, it pitches the nose up or down, it changes the attitude and the speed.’ Demonstrated by moving the stick forward and seeing the horizon position change and the speed increasing then stick back to slow down to the stall which involved a ‘nose drop’ showing that the elevator won’t always raise the nose.
    Ailerons
    ‘The primary effect of the ailerons is to roll the aircraft to a bank angle’. Demonstrated by moving the stick to left or right and seeing the response.
    Rudder
    ‘The primary effect of rudder is to yaw the aircraft’. Demonstrated by applying rudder one way or the other and seeing the response.
    Secondary effects:
    There were always a few puzzled looks when we explained that two of the controls had secondary effects!
     Ailerons
    ‘The secondary effect of ailerons is to yaw the aircraft’. Demonstrated by holding the rudder central and moving the stick from side to side which produced a yaw in the opposite direction to the roll (adverse yaw). Explained very briefly by stating that the down going aileron produces more lift but also more drag, like having a little man on the wing tip pulling it back! We cheated in the first aileron demo by applying rudder to mask the effect.
    Rudder
    ‘The secondary effect of rudder is to roll the aircraft.’ Demonstrated by holding the stick central and applying rudder, the glider would yaw then roll. Again we cheated in the first rudder demo by using opposite aileron to stop the roll. Some students did notice this cheating going on!
    By the end of the first day the ‘studes’ had a good grounding of the effects of controls and the standard terminology (pitch, roll and yaw).
    Stability
    On these basic courses we did not go much further with theory but for advanced courses (Bronze ‘C’ badge level) the knowledge requirement was more in depth but still simple enough to understand.
    The axes were introduced (normal, lateral and longitudinal) and stability features were explained. Other concepts such as differential aileron design and washout were also taught.
    The answers were often squeezed out of the students by firing questions at them, i.e. ‘what gives stability in pitch?’
    We would fill out a table on the blackboard which I have reproduced below:
    table.tableizer-table { border: 1px solid #CCC; font-family: Arial, Helvetica, sans-serif; font-size: 12px; } .tableizer-table td { padding: 4px; margin: 3px; border: 1px solid #ccc; } .tableizer-table th { background-color: #4297C9; color: #FFF; font-weight: bold; }
    Control Axis Primary Effect Secondary Effect Stability Elevator Lateral Pitch None Tailplane Ailerons Longitudinal Roll Yaw Dihedral Rudder Normal Yaw Roll Fin I always thought that time spent on this subject was important, it can certainly help us modellers to understand how our gliders behave.
    The ultimate use of this is understanding what is happening in a side slip manoeuvre, yaw is applied with the rudder to change the angle of the fuselage for more drag, opposite aileron is applied to stop the secondary effect (roll) of the rudder to keep the wings level  and elevator is used to maintain a constant pitch attitude. I've always wanted to try this with a radio-controlled model but I would have the disadvantage of not sitting in the cockpit to see what is going on!
    Cheers
    Gary Binnie

    By Gary B, in Articles,

    Hi folks, I was asked to write an article on a method of weighing large model gliders after I wrote a short ‘how to’ on RC Groups, so here it is!!
    Introduction:
    My background is 20 plus years service in the Royal Air Force as an airframe engineer and a lifelong aeromodeller, I currently work in Formula 1 aerodynamics. During my military service I took up full-size gliding as a hobby, became an instructor and tug pilot but perhaps more relevant to this article I applied my aircraft engineering knowledge to maintaining club gliders as a volunteer inspector. Later I took up a full time post as a gliding instructor/tug pilot/engineer for four years (it got me away from the ‘fast jets’ and there are worse jobs!!).
    I have a couple of 4 metre span model gliders and recently I refitted one with new radio gear and battery. Realising that I needed to check the centre of gravity (abbreviated to c.g. from now on) I had two choices, lift it on my finger tips in the traditional way or buy one of those neat but relatively expensive balancing rigs.
    A third choice came to me, why not try and weigh it like I used to weigh the full-size gliders? It was a wet afternoon so I tried it and it worked!!
    The importance of the centre of gravity position:
    I would think that model pilots and builders reading this will already know about the importance of the c.g. (some people call it the ‘balance point’ and they are technically correct) and may have found out the hard way but others may not so I thought I would add a few words on the importance of the c.g..
    All full-size gliders have a range of the c.g. for flight to allow for different weight pilots and the addition of water ballast in the wings and tail fin (vertical stabilizer) where it is used.
    Model kit manufacturers usually give a set position or also a range, like the full-size.
    Let’s look at the effects in flight of various positions of the c.g., they are the same for both models and full-size (ever seen ‘Flight of the Phoenix?!!).
    Forward c.g.:
    A c.g. close to the forward limit (or beyond it!) i.e. nose heavy will have the following main effects:
    Ineffective elevator with slow control response in pitch, may not ‘flare’ out after the landing approach unless carrying extra speed! Reluctance to stall or spin (you may be looking for this characteristic though). Difficult to slow down and trim to a normal gliding speed. Aft or rearwards c.g.:
    A c.g. close to the rear limit (or beyond it!) i.e. tail heavy will have the following main effects:
    Very effective elevator, ‘twitchy’ or uncontrollable in pitch. Worse at higher speeds on aerotow. Prone to stalling/spinning. Unable to trim for higher speeds. Gary waiting to be aerotowed.
    Full-size glider weight and balance:
    It is obviously important that full-size gliders are weighed accurately to determine the empty c.g. (calculations are done afterwards to determine the minimum and maximum cockpit weight) and, not so obviously, to determine the weight of ‘non-lifting’ parts for structural strength/load factor reasons (wing bending loads).
    Gliders are generally weighed when they are new and after repairs/repainting. National regulations apply. They are also sometimes weighed with the pilots on competition grids to make sure that they are not overloaded!! Once they are weighed a sheet is completed for the logbook and a placard fitted in the cockpit with the loading limitations.
    The process of weighing a full-size glider involves weighing all the components separately (fuselage, wings and tailplane) then rigging it and weighing it as a complete machine.
    Before the advent of electronic scales large spring balances were used (and probably still might be at some establishments!), the difference being the accuracy and ease of weighing a glider on top of scales rather than slinging it from above by the hangar roof beams or small cranes. Modern glider factories have load cells set into the floor, even easier.
    The glider is placed in the flying attitude using an inclinometer, datum lines are drawn using chalk on the floor and distance measurements are taken (or are sometimes given by the manufacturer). These distances (the ‘moment arms’) are combined with the measured weights to work out the c.g..
    For more on the subject of full-size glider weighing here is a link to the British Gliding Association procedure:
    Gary enjoying some full size Gliding
    Garry Binnie
    By Mike O'Neill
    Way back in the early 1980’s, and for a brief time only, I rubbed shoulders with some of the (then) notable names in r/c gliding: Sean Bannister, Chris Foss, George Stringwell, Chas Gardiner, Alan Head, Nick Wright, Colin Paddon, Bill Dulson, John Goldsmith, Steve Mettam, John Shaw, Dick Edmunds, Graham James(?) etc. etc. etc.
    I designed a big V-Tail open class model based on the E193 airfoil, with aileron control and half span, quarter chord flaps to assist rapid (and safe) launching, improved thermalling and offering phenomenal landing performance when the flaps were lowered to 90 degrees.  With virtually no experience of competition flying, I took this glider up to Radioglide 84 in Scotland and, by a combination of radical/original design and incredible good fortune, scored three perfect scores in the rounds over the unsuspecting competitors, and a perfect score in the first fly-off. Nobody expected what this plane could do: in particular (as George Stringwell wrote at the time) “...the approach and landing was a joy to behold, since the plane appeared capable of maintaining a 70 degree dive with no increase in airspeed”. I was unlucky in the second fly-off in that an aggressive and well known pilot flew into me as I approached the landing circle, taking the tail off  his plane and depriving mine of the energy to make the landing circle. I placed 9th instead of somewhat higher, but I did win a special design award that I cherish to this day. And me and Colin Sparrow came 3rd in the team trophy.
    Fast forward 30 years, one marriage and three grown up kids later (jeebers, where does the time fly) and I still liked to think I had  r/c planes to fly even though I’d not had time to do it.  But as I reached for my r/c stuff to do a bit of flying in my rediscovered leisure time, I realised just how much time had ravaged my ambition. My old Futaba Gold and Sanwa Black Custom sets were – apart from having duff batteries – severely short on functionality compared with the now prevalent 2.4Gz radio control equipment. And my planes hadn’t fared much better. The veneer had started to de-bond from the cores of the foam winged models, the dope and spray paint was cracked and crazed from wooden fuselages carved originally to look like sleek fibreglass moulded efforts, and the solarfilm coverings were looking decidedly dog-eared.  What is more, I’m still working and I have a house to run on my own and many other commitments and I don’t have the kind of time needed to restore my old stuff right now. But I do have enough time to nip out and fly briefly and, as if to taunt me, my new house is one minutes drive from the lovely and peaceful field where the Timperley Model Club do their flying. Something had to be done.
    Happily, oh so happily, we now live in the age of the internet, so that I could start researching and reading up on what the modern model flyer was getting up to.  Much as I drooled over the state of the art hand built Czech competition models and what they might do in the air, I didn’t want to spend that kind of money (I’d been fullsize gliding in the intervening years and a ¼ share in a fullsize K6 cost me less than one of these things would have!). But I did want if possible to find something that would fully engage my interest in soaring in the way that fullsize gliding had done.
    From my researches, I became aware that lithium polymer batteries were now becoming safe enough for ‘normal’ use by modellers. This opened up the possibility of an electric glider whose soaring ability would not be unduly compromised by battery weight. The idea was attractive as it would dispense with time wasting bungee deployment and allow me to set up and pack up much more quickly. And for any after work flying sessions, the sooner I could get airborne the greater my chances of catching the last of the day’s thermals before they disappeared. I really didn’t want one of the foam moulded toys (as I saw them) but began to change my view when I visited the Timperley MFC field and saw the Parkzone Radian in action. Several people had one and they all recommended it as the best option for me.  I had to concede it was a pleasant, impressive and forgiving thermalling machine for light wind conditions: the electric motor simply substituted for the bungee that a pure glider would have needed. But I just fancied something a bit more challenging and potent, more able to handle windier days, and preferably larger so I could fly higher and further and still see it.
    And so I started searching to find out what ready to fly electric gliders people had been opting for, and what they thought of them.  Nothing apart from the Radian really jumped off the pages of the various internet blogs and forums, until I came across the Art-Tech Diamond 2500.  This was one of only two suitably featured RTF electric gliders I came across with a span as big as 2.5m (the other being the same design, but branded and marketed by Multiplex). And it was offered absolutely ready to go including 2.4Gz transmitter, motor, speed controller, 6 servos (2 aileron / 2 flap / 1 elevator / 1 rudder)  and 4 cell LiPo battery pack, all for a little over £200: an incredible deal.  It got good flight reviews and it looked great, with a cavernous fuselage (should I want to install telemetry gear, FPV , whatever) and landing wheel. There was some suggestion that the component quality was not all it could be, but it seemed to me – reading between the lines – that none of this was a deal breaker.  And so I bought one, in the summer of 2014. It took a little doing, as everyone was out of stock. But my local model shop – Steve Webb Models in Frodsham – reckoned they could order one in within a week, and their price was the best I’d found also.
    One week later and the Diamond was in my hands. I opted to buy a decent new transmitter and receiver (Spektrum DX9) as I wanted to do some fancy mixing of flaps and aileron surfaces to replicate the equivalent functions in a fullsize flapped glider. This was not possible with the cheap Tx and Rx that came with the plane, but they could be reassigned for use with my old simple gliders (Graupner Amigo, wooden Chris Foss Centiphase, 1948 Thermalist, Algebra Open Class etc.), so they wouldn’t be wasted.  It took no time to fettle the Diamond ready for flying. I put a strip of fibreglass adhesive tape along the underside of the fuselage and wing tips to protect them against abrasion, and I worked all the control surfaces to remove stiffness before putting the servos to work, in order to avoid undue strain on them. I also replaced some of the cheap tape covering the wing servo wire channels. I mastered the mixing (on the DX9) of flaps and ailerons, how to mix in elevator trim compensation, plus switchable coupled aileron and rudder, aileron differential, switchable motor disabling, and how to start timers from key controls (e.g. throttle up).  And the DX9 had voice options too, which I made good use of. I set the wing surfaces up for launch, speed, cruise, thermal and landing configurations. In the last case, the flaps move down to their 45 degree limit and the ailerons move about half that in order to ensure good control response etc. though I’ll experiment with the settings in time.  I removed the supplied metal weights embedded in the wingtips in order to lighten the plane. These weights are interesting. Some owners think they are there to dampen roll sensitivity and make the plane easier to fly. This may be true, but I wondered if they might also be there to reduce overloading that part of the wing where the long aluminium tube wing joiner ends and the wing becomes pure unreinforced foam. By fitting weights out near the tips, the outer panels are forced down by centripetal force when the plane is pulled out of a dive. This reduces the strain on the vulnerable section where the joiner ends.  Anyway, I removed them, and I’ve flown a few loops since with no ill effect, though I have a mental note that I should be careful with all this.
    The plane flew really well from the word go, and all the various flying settings worked a treat.  A few things though were still left to address.  First, I’d read that the plastic folding prop was prone to shedding a blade due to the power being put through it. A consequence of this could be to rip the motor out of its mount. Second, there was a very audible whistling sound as the plane flew overhead and close. Lastly, the aluminium spar/joiner was very long and weighed a bit, and might also be prone to bending.  I had read that a carbon fibre spar could be got that would fit perfectly and that it would save yet more weight.
    So I bought a decent prop and fitted it. And because I suspected the extremely blunt trailing edges to the control surfaces was the cause of the whistling, I decided to address this and to increase the wing area and control response of the plane in one move by glassfibre taping balsa trailing edge stock to wings, elevator and rudder. By doing this I added about 10% to the wing chord and aimed to reduce the drag caused by poor airflow separation at the trailing edges. The next flight proved the worth of all of this. The new prop gave a much crisper climb to height (near vertical climb out to 500 feet in just a few seconds).  The whistling noise vanished, and the plane was altogether more capable when it came to slow circling flight. It seemed to fly quicker too when flaps were set at a negative (speed configuration) angle. And obviously the braking effect of flaps improved, and the elevator and rudder controls became more efficient as smaller deflections were needed to achieve the required degree of control.  This was now a really capable sports glider. It was easy to thermal and was very stable in the turn (I have a set up for coupled aileron / rudder if I’m feeling especially lazy, though it barely needs it and will almost turn rudder only due to the curved up outer wing panels ).  It moved across the sky very respectably and handled loops and rolls, the latter despite me opting for a 2:1 differential on the ailerons (this is primarily a soaring machine after all). It managed about a dozen bungee height climbs on a battery pack. And it could be landed at very slow speed, with a steep approach, into a confined space, and under good control.  It wouldn’t compete with serious competition machines obviously, but then it was probably much easier to fly than they are (and a lot cheaper too). And it looked great, resembling a fullsize design with its generously proportioned fuselage and pleasant lines. All in all, the Diamond 2.5m gave  me a plane that I could just go out and fly if I wanted, but that I could fiddle around with and fettle, should I choose too. Looking ahead, I might for example decide to make it some fancy sectioned, properly sparred longer wings for extended thermalling and distance flying.  And as soon as I can source that carbon fibre tube for use as a wing joiner, I’ll definitely try out that mod.
    It’s good to be back flying. And it’s amazing (but not surprising) that the (flapped) features I had no option but to spend a lot of time designing and building for myself all those years ago have now become a readily available feature on an RTF plane costing so little to buy, and taking no time to make.
    Mike O’Neill

    By Sydney Lenssen, in BARCS,

    By Sydney Lenssen.
    As newly anointed president of the British Association of Radio Control Soarers, I should like to join with chairman Robin Sleight and members of the committee to wish all Barcs members, and indeed all soarers, a very happy Christmas and successful New Year, with plenty of thermals at the right time.
    As we approach the New Year, many of us make resolutions. Some do not last for very long. Allow me to suggest a special set worth keeping for the whole year.
    The internet has made a fantastic difference over the past few years to competition flying and especially the organisation of contests. One of the less fortunate aspects of the widespread use of computers is that securing entries into the various events is left until the very last moment. Often the matrix is being juggled late into the night before the event. Early in the morning, whatever the weather, the same dedicated handful of people set out the field and assemble the equipment. And most times, it is the same few people who clear up the field and load all the bits and pieces to take home for the next time.
    My simple suggestions, if we want make sure that competitions thrive, are these:
    As soon as you have decided to enter, then let the organiser know as early as possible, preferably two or three weeks beforehand. Unless you have a 200 mile drive or more to get to the site, then please turn up at least 30 minutes before you start assembling your models and setting out winches, and help. Finally, and perhaps most importantly, stay behind after the prize giving until the field is packed up and clear. That will make everyone much happier. Please, let us do it!
    Sydney Lenssen

    By Robin Sleight, in News & Information,

    Keith Miller’s recent passing is a sad loss to the sport and soaring activities in particular. A detailed obituary is now posted on the BMFA web site but, in many ways it does not do full justice to Keith’s contribution to thermal soaring, especially in the South East where he ran the Tonbridge Open for many years and was a key person in the establishment of the series of events run by Kent Clubs. Keith was truly one of the world’s gentlemen always cheerful and available and willing to help. In addition to the BMFA obituary the following comments from his club-mate Keith Fisher sum up for many of us the contributions which Keith made.
    “I knew Keith since I was first dragged screaming and kicking to a thermal flying comp around 1988, I had come from tearing around slopes with as much lead as the plane could possible take. Keith taught me to slow down and look for this magical but invisible thing called a thermal, we would meet up on a Sunday morning, usually in the mud at Leigh park, where his patience would be tested with me going up a bungee, and landing at the same as the parachute. Perseverance was rewarded and soon was taken to my first comp at Wrotham, representing the club in the Ron finnis from there the bug had bittern, and along with Rob Love we would travel to Essex, and Sussex with Keith, where all the journey he would tell stories of his early car racing with a riley or his flying days in the RAF. I was lucky enough to see Keith recently at Leigh trimming out a free flight rubber powered plane, where the usual me taking the mickey out of" spending all that time building a plane just to let it fly where it wants" was rewarded with a smile, Keith will be sadly missed at the club, in life and as a friend”.
    I too value the help and support which Keith so frequently and so willingly always provided.
    Robin Sleight, BARCS Chairman
    More on Keith from the BMFA website
    Link to Forum topic.

    By Austin, in BARCS,

    BARCS Soaring Market 7th December
    Time to mark the date in your diary for the annual Soaring Market and Bring & Buy.
    The event will be held at the usual venue Oadby Leisure Centre, Parklands, Wigston Road, Washbrook Lane, Oadby, Leicestershire LE2 5QG  (See map below). Entrance from 9am closing around 1pm.
    Traders already confirmed are
    Deluxe Materials have joined the list of traders attending. They are also offering a show discount as detailed below
    Follow our catalogue  download link http://www.deluxematerials.com/download/Brochure.pdf
    If people want to order in advance they can with the order form attached. If they do this and order £30 or more a 10% discount applies for collection  only at this show . They should add what they want to order on Column D and email it to Deluxe Materials john@deluxematerials.com  by Wed 3rd Dec and if its 30 or more we will discount by 10%.
    Oadby Deluxe Materials order for collection
    BOWINGS Leading F3K pilot Richard Swindells will be displaying the new all composite Stream DLG – http://www.bowings.co.uk
    eSOARING GADGETS Bernie Jones is fast gaining a reputation for his fast and friendly service as one of the leading suppliers of electric gliders, radios and electric flight equipment being agents for Valenta Models, Jeti Radio, Overlander, RC Electronics – http://www.esoaringgadgets.co.uk
    FLYING DOG Stockists of Blejzyk Gliders as well as a wide range of kits, materials and accessories aimed at the indoor market – http://www.flyingdog.co.uk
    INWOOD MODELS Need a new radio, servos, kit, materials, Dave Handley and his team will be on hand to meet your – http://www.inwoodmodels.com
    As well as BOB MOSELEY (formerly Fine Flight) with his usual range of kits and unusual items.
    Why not order your goods in advance.
    Many more have been invited, look out for updated bulletins in the weeks to come.
    There will also be displays of F5B and other soaring disciplines with people on hand to give impartial advice on how to get into the sport.
    And don’t forget the Bring and Buy. There will be tables available to display your unwanted modelling gear FOR FREE. All you need to do is bring it along, marked with a price and contact mobile should you wish to wander round the hall.