Peter Jenkins

I am pleased to announce Edition 3 of my book, Model Aircraft Precision Aerobatics. Edition 3 of this book introduces the new UKF3A Entry Level Schedule as well as describing how to fly the UKF3A Association Clubman and Intermediate Schedules. This Edition also includes a new section on RC Transmitters and the functions that are particularly useful for precision aerobatics. This book is a guide both for beginners as well as improvers to model aircraft precision aerobatics, or F3A, competition focused on UK schedules. However, it is just as relevant anywhere else in the world as the issue of how to control an aerobatic model aircraft is not limited to a single geography! If you are not interested in entering competitions, this book will bring you some of the knowledge and techniques that you would only pick up by attending them. If you are sufficiently disciplined in your flying, there is no reason why you should not reach a good aerobatic standard after following the advice and guidance contained in this book. The book is available from Amazon in Kindle (£8.99 ), Paperback (£31.82) or Hardback (£35.79) versions as at Jan 2025. Forum members can PM me and I can supply the books including 1st class post and packing (within the UK) for: Paperback £24 and Hardback £28, as at Jan 2025. I will send to addresses outside the UK but will have to add the additional postal costs involved.

Kevin Caton and I are pleased to announce Edition 2 of our book Advanced Precision Aerobatics. Edition 2 of this book updates the practical advice on how to fly the A and P FAI schedules based on Kevin Caton's experiences during 2024 which includes flying in the European FAI F3A Championships. The book also provides information on how to use the Flight Coach system during practice in order to identify what you are doing wrong when flying manoeuvres. This book is for those who are new to or attempting to improve their performance of the FAI Model Aircraft Aerobatic Schedules A25 and P25. The book covers the topics of trimming, transmitter setup, aircraft and control setup, how to practice effectively, countering wind effects and what is involved in competition flying. The FAI P25 or Preliminary Schedule is flown in all Continental and World Championships and is usually used in National Competitions. The FAI A25 or Advanced Schedule, is the precursor to the P25 and has the same manoeuvre geometry but with fewer in-manoeuvre elements. The objecting of flying A25 is that it enables an easier transition to P25 as the overall geometry remains the same. In the UK, both A25 and P25 are used in the National League competitions. The book is available from Amazon in Kindle (£9.49 ), Paperback (£26.99) and Hardback versions (£31.20) as at Jan 2025. Forum members can PM me and I can supply the books including 1st class post and packing (within the UK) for: Paperback £20 and Hardback £25, as at Jan 2025. I also have some remaining copies of Edition 1 of this book at £14 including P&P (within the UK). I will send to addresses outside the UK but will have to add the additional postal costs involved.

A full size powerful aerobatic aircraft has about 315 bhp/ton. An F3A aerobatic aircraft has almost 800 bhp/ton! That's so you can fly at a constant speed around a loop. Watch a full size and they can't do that. It's a bit like a fighter. As any fighter pilot if they'd like more power and they'll say "YES"! 👍

Words of wisdom I was in the six item express lane at the store quietly fuming. Completely ignoring the sign, the woman ahead of me had slipped into the check-out line pushing a cart piled high with groceries. Imagine my delight when the cashier beckoned the woman to come forward looked into the cart and asked sweetly, "So which six items would you like to buy?" (Wouldn't it be great if that happened more often?) ------------------------------------------------------------ Because they had no reservations at a busy restaurant, my elderly neighbor and his wife were told there would be a 45 minute wait for a table. "Young man, we're both 90 years old," the husband said. "We may not have 45 minutes." They were seated immediately. ------------------------------------------------------ The reason Politicians try so hard to get re-elected is that they would "hate" to have to make a living under the laws they have just passed. ------------------------------------------------------ All eyes were on the radiant bride as her father escorted her down the aisle. They reached the altar and the waiting groom. The bride kissed her father and placed something in his hand. The guests in the front pews responded with ripples of laughter. Even the priest smiled broadly. As her father gave her away in marriage, the bride gave him back his credit card. ------------------------------------------------------ Women and cats will do as they please, and men and dogs should relax and get used to the idea. ------------------------------------------------------ Three friends from the local congregation were asked, "When you're in your casket, and friends and congregation members are mourning over you, what would you like them to say?" Artie said, "I would like them to say I was a wonderful husband, a fine spiritual leader, and a great family man." Eugene commented, "I would like them to say I was a wonderful teacher and servant of God who made a huge difference in people's lives.." Al said, "I'd like them to say, 'Look, he's moving!'" ------------------------------------------------------------ Smith climbs to the top of Mt. Sinai to get close enough to talk to God. Looking up, he asks the Lord. "God, what does a million years mean to you?" The Lord replies, "A minute." Smith asks, "And what does a million dollars mean to you?" The Lord replies, "A penny." Smith asks, "Can I have a penny?" The Lord replies, "In a minute." ------------------------------------------------- A man goes to a shrink and says, "Doctor, my wife is unfaithful to me. Every evening, she goes to Larry's bar and picks up men. In fact, she sleeps with anybody who asks her! I'm going crazy. What do you think I should do?" "Relax," says the Doctor, "take a deep breath and calm down. Now, tell me, exactly where is Larry's bar?" ------------------------------------------------- John was on his deathbed and gasped pitifully, "Give me one last request, dear," he said. "Of course, John," his wife said softly. "Six months after I die," John said, "I want you to marry Bob." "But I thought you hated Bob," she said.. With his last breath John said, "I do!" -------------------------------------- A man goes to see the Rabbi. "Rabbi, something terrible is happening and I have to talk to you about it." The Rabbi asked, "What's wrong?" The man replied, "My wife is going to poison me." The Rabbi, very surprised by this, asks, "How can that be?" The man then pleads, "I'm telling you, I'm certain she's going to poison me. What should I do?" The Rabbi then offers, "Tell you what. Let me talk to her, I'll see what I can find out and I'll let you know." A week later the Rabbi calls the man. He says, "I spoke to your wife on the phone for three hours. You want my advice?" The man said, "Yes" and the Rabbi replied, "Take the poison." ------------------------------- I was always taught to respect my elders, but it keeps getting harder to find one.

"If we can manage to convince the Chinese that Jihadists' testicles are aphrodisiacs, within ten years they'll have disappeared..."

The Washington Post’s Mensa Invitational once again invited readers to take any word from the dictionary, alter it by adding, subtracting, or changing one letter, and supply a new definition. Here are the winners: 1. Cashtration (n.): The act of buying a house, which renders the subject financially impotent for an indefinite period of time 2. Ignoranus: A person who's both stupid and an asshole. 3. Intaxicaton: Euphoria at getting a tax refund, which lasts until you realize it was your money to start with. 4. Reintarnation: Coming back to life as a hillbilly. 5. Bozone (n.): The substance surrounding stupid people that stops bright ideas from penetrating. The bozone layer, unfortunately, shows little sign of breaking down in the near future. 6. Foreploy: Any misrepresentation about yourself for the purpose of getting laid 7. Giraffiti: Vandalism spray-painted very, very high. 8. Sarchasm: The gulf between the author of sarcastic wit and the person who doesn't get it. 9. Inoculatte: To take coffee intravenously when you are running late. 10. Osteopornosis: A degenerate disease. (This one got extra credit) 11. Karmageddon: It's like, when everybody is sending off all these really bad vibes, right? And then, like, the Earth explodes and it's like, a serious bummer.

Hi Frank My understanding is that with the alarm set at, say 3,600 mAh, there will be no voice alarm till that limit is reached. The alarm would probably say Bingo 1, and a second alarm when I reach 4,000 mAh of Bingo 2. I'm not interested in getting the system to tell me how much is remaining just those words that tell me "fuel" is low and "extremely low" so time to land! If I've been struggling with an aerobatic schedule in very windy conditions I don't want to have numbers suddenly announce themselves those words will be sufficient.

You'll find Flight Coach here. As I say, it's primarily designed for F3A Aerobatics but can be used for anything provided you develop the necessary analysis software. It uses an Arduino flight control board and GPS sensor and the link gives you all the details you need to set up the hardware. The display software is all bespoke as far as I can tell. As it's a standalone system, you don't get any in-flight guidance and currently the FAI does not allow FC to be used in any FAI competitions. The originator of FC is working diligently to try and get it adopted as a judging system and the first attempt at this was recently launched called FCScore. I have run a few of my flights through it but I am not sure what the analysis of the score is telling me other than I need to buck up my ideas!

Hi Adrian I can't remember if I pointed you at the SM Modelbau UnisensE package. That takes a lot of beating given its price and what it covers. You get: RPM, drive voltage, drive current, drive power (OK that's just multiplying the first two together), capacity remaining (you have to enter the flight pack capacity for that to work properly but you can do that on your Tx), height, and rate of climb/descent for gliders. Not bad for around Euro 65.90 plus postage. I would have thought it shouldn't get caught by the VAT/duty police for that amount. There is a small utililty program to download to your PC that allows you to upgrade the firmware and set up the UnisensE. It worked fine on my JR and even better on the Jeti as the Jeti records all the data in the Tx and you can review it after landing and shutting down. With JR, you only got max/min and real time. I expect your Futaba will be like the Jeti but I don't know.

Hi Dick, if you take a look at my post here at 14:48, you will see the type of trace that I use. The guys driving Flight Coach have been developing it for 10 years and are now moving to trying to judge aerobatics using various mathematical techniques that are beyond me. It requires a decent size screen to view the flight and look at all aspects of the aircraft's orientation. You can twist the picture so you can view it from the judges/pilots view, from the top, from each side and from an infinitely variable viewing angle. So, it's a bit more than just looking at a ground track although it also covers that. I am perfectly happy to drag the laptop along when the weather isn't freezing cold though.

Hi Dick I've only really explored Jeti Studio for the Tx and Rx firmware updates. I should have said that the main reason I look at the telemetry logs after flight is to check the opening height - aiming for between 850-900 ft and whether there were any other spikes that went beyond 900 ft. After that, I use the Flight Coach system that gives a trace of the flight giving each manoeuvre showing its geometry, size and positioning in all 3 directions something that the Jeti telemetry cannot help with. Height plus capacity used, which I record and then compare when I recharge the pack, are what are primarily of use to me. Thanks for pointing out the option of using a mobile phone but that's not a great help in the circumstances. Others who don't have my specific requirements might find that suggestion of great use though.

Good to know Paul. Same as the Jeti then. Adrian, although there are 4 switches on each side of both the JR and Jeti Tx, the JR had all 3 position switches bar one 2 position switch. The Jeti came with mostly 2 position switches. I only use 3 switches on the left side and one on the right hand side. I use colour plastic sleeves to denote their function. Red is the Kill switch, with blue being flight modes, black being the ground handling and yellow the mixes. As it happens, I had been thinking of incorporating the downline mix switch into the main flight mode switch and now I've also moved the KE mix switch to the aero flight mode switch as I've now sorted out that mix so the yellow switch is now redundant. The photo below shows what I mean. Oh, I do use one of the rotary switches to adjust the volume of the alarms/voices from the Tx. Low at home and turned up at the field. The only spoken "guidance" is the lady announcing the time to run every minute. I found that a bit distracting to begin with but quite like it now. I will set a capacity alarm at 3,500 mAh used and a final one at 3,800 mAh used - I'm using a mix of 4,800, 5,000 and 5,200 mAh packs. If all goes well, I use between 2,900 and 3,300 mAh per flight.

I have always kept a paper log of every flight I have made from the time I re-started RC flying in 2000! A hang over from full size aviation. I will write down any specific information especially when trimming aircraft. I've only just become a Jeti user with my first Jeti flight on the 28th Dec '24. I also use a system called Flight Coach that requires some hardware in the aircraft (arduino autopilot and a GPS) that captures the aircraft's flight and allows you to replay your flight. However, this is specifically for F3A aerobatics with a schedule being flown and the data analysis is all linked to the specific FAI schedule manoeuvres so not a lot of use if you're doing other flying. I do download the flight data from the micro SD card at the end of every flying session and do a review of the flights. You get some quite helpful information particularly regarding whether you had wings level as you enter and leave manoeuvres as this is easily displayed. I use a 3rd party onboard telemetry device (SM Modelbau UnisensE) that gives a wide range of parameters and can be made to speak almost any radio brand dialog including Jeti. I do find being able to review the Jeti logs after each flight, particularly on the height trace very helpful. If I really want to review the flight I have to take my laptop with me and plug in the FC memory card to get the full flight debrief. I have done that but it does rather interrupt proceedings if you are short of time for the flying side!

One thing I did find with the Jeti was that you can buy additional switches (2 position, 3 position, long, short, spring loaded, locking etc) and they are very easy to replace as they just need to be unscrewed (special tool needed) and unplugged and the new one plugged in and screwed into place. That having been said, the switches don't feel as silky smooth as those on the JR. Does Futaba provide for that?

Well done. Like everything, easy when you know how! Biggest problem is forgetting what you did so that the next time it's like starting from scratch - almost. I write down the process and put an insert in the Tx manual.

Didn't they sell rocking horse poo as well?

Like Adrian I was suffering withdrawal symptoms. I'd had 2 abortive visits to my No 1 field - fog/low cloud did for the first one and a cockup on our booking system the 2nd. So, at the No 2 site and it was glorious this afternoon. Probably less than 10 mph at around 15 deg to the display line. Got in 4 flights and the Jeti Tx went from 92% to 82% on the battery indicator. At this rate it probably be OK to have 4 sessions from fully charged before re-charging. As ever, the Anthem flew well, but its pilot not so! I've decided that the snap speed needs to be a bit faster but not too much faster as it then gets more difficult to stop it at exactly the right place. The ability to review the Jeti telemetry recording is a great help when I look at the height trace to see that I am still not regaining the initial entry height for my opening manoeuvre - that's a triangle loop entry at the top and inverted and exit tends to be about 100 ft lower as you can see from this Flight Coach Plotter screen grab. I'm also flying too steep an initial 45 down line and not using enough rudder to maintain the flight path in the 2 x 1/4 rolls on down leg. Also, the bottom line is not level, even though it looked it! Lots to work on there! The 2nd last flight had the best triangle shape but still a lot of tidying up to do.

Coefficient of lift. Normally written as C and little L. It's fellow non-dimensional number is the coefficent of drag written C and a small D A Clark Y wing section will have a Cl ofaround 1.5.. Total lift is given by the equation: L= Cl x 1/2 (air density) x velocity squared x wing area.

I don't know your particular issue with the CAA but it seems to involve full size flying and from that you are attempting to draw a parallel to the model aircraft world. I have dealt with the CAA when I used to fly full size and didn't have a problem with anything. So, that's a counter to your issue. I've been flying model aircraft since 1963 starting with C/L in the local park. I can say with complete sincerity that the actions of the BMFA, the CEO in particular, has meant that the rules we now fly under mean that, apart from having to pay around £10 for a OP ID, we can carry on as we did before. All of those who whinge and moan about the CAA cannot spend much time flying model aircraft is all I can think of. So, it's a great pity that while you followed this thread it never occurred to you to post on something that was relevant to the thread instead of a generalised gripe about something that happened to you in full size flying. As for gold plated rules, there are no gold plated rules that apply to the flying of model aircraft under the BMFA's auspices. Perhaps you should try reading them before you throw your toys out of your pram?

and they've both recommended that the other department should be cut!

Whilst I don't claim to be an expert aerodynamicist, I did work with some exceptional ones when I worked in a company called QinetiQ. This was 75% of the MoD's Defence Research Labs that was privatised. It included the Farnborough and Bedford aerodyamics groups and one of only 3 large pressurised wind tunnels in the world. Boeing has used this wind tunnel for all its low speed aerodynamics work since the original 747. The group also worked with Airbus on a number of aerodynamic projects including winglets. The team came to see me to say that they felt there was a business opportunity to retro fit the 777 which didn't have winglets as you point out. Their theoretical work indicated that the drag saving in cruise, a relatively low Cl, would be of the order of 8%. On a trans-Atlantic sector that's a significant cost saving. The guys wanted to test their design in the 5 Mtr tunnel and as the tunnel had to be run after a major refurbishment to re-calibrate it they thought adding in the winglet test would cost around £50k. On the basis that the design was not beholden to any work we'd done for Airbus and the team's expertise in CFD to arrive at this unique shape, I signed off the expenditure. The wind tunnel test showed that the drag saving was almost 9% and so that was very encouraging until the team said that sadly they had made a mistake and the shape they were proposing had indeed been part of the work they did for Airbus. Clearly, we couldn't offer this to Boeing but did offer it to Airbus. The latter had decided that using a raked wing tip produced very similar drag reduction to a winglet at less cost so that was the route Airbus took. None of this is perspective. It is all hard fact and has stayed vividly in my mind given the £50k loss to the bottom line that year! I should also say that the then team of aerodynamicists were, and for all I know might still be, world class. Otherwise, they wouldn't have been engaged by Airbus to help them with their designs or on other military programmes.

From a theoretical standpoint, a 2 D wing, that is one of infinite span, doesn't suffer any tip losses as there are not wing tips to generate vortices that increase aerodynamic drag. What the winglet does is to try and make a 3 D wing i.e. one of finite length as opposed to 3D aerobatics(!), approximate to a 2D wing. The greatest savings are in the cruise mode. Typically, winglets on airliners made a reduction of around 5% which will result in a 5% reduction in fuel burn which is a sizeable figure on a long flight given the price of aviation fuel today - remember that for international flights that ICAO agreement is that no government will charge tax on fuel as otherwise you end up with airliners flying around full of fuel from the cheapest source. For full size high performance gliders, the advent of fibre glass construction meant that for the first time it became realistic to use winglets to try and reduce the strength of the trailing vortex and a 5%+ reduction in drag on a final glide made a noticeable difference since skin friction and airfoil accuracy were greatly improved over the traditional wood with fabric covering. Thus glide angles of better than 1:50 were achievable. On full size you will not find winglets on low aspect ratio wings as their cost outweighs their benefits. On a model aerobatic aircraft, using wing tip plates will provide extra yaw stability or instability depending on how much of the plate is in front of or behind the CG. You tend not to see wing tip plates on precision aerobatic aircraft but are more likely to see wing fences employed where there is a change in wing taper. What a wing fence does is to reduce the span wise airflow that both increases the wing's lift as spanwise flow does not generate lift. It will also tend to improve aileron effectiveness although this is probably only noticeable to a really expert pilot. For the average club pilot the use of winglets is pure fashion since they are unlikely to be able to tell the difference between having the winglet on or off. The overall design of the aircraft which comes will such wing tip plates will probably be so much better even without the winglets compared with a standard club model. The true comparison comes with flying said winglet equipped aircraft with and without the winglets and seeing if you can tell the difference. It might be that the winglet helps in snaps or spin entry but again individual pilot skill is the dominating factor.

Toto, isn't it time to change the heading to fifth (at least) taste of the sky? It's stretching advertising standards! 🤣🤣

Sadly Cuban 8, and all those who share your views, you have missed one vital point. The airspace is owned by the Government. This is quite separate from land and sea where the Government doesn't automatically own all the land and sea. Many people are unaware that they don't even own the airspace directly above their house. Furthermore, there was a decision taken by the EU back in 2014 or so (I forget exactly when but it was a long time ago) where they saw that the use of unmanned aerial systems provided a great way in for a new industry that could avoid getting tangled up with the usual aviation procedures and allow a lower barrier of entry for a large number of companies. The idea being that a lot of new businesses would be enabled by using unmanned systems. Of course, the regulators were put in charge of making this happen which is why it is taking so long. The biggest impetus to unmanned systems, actually any new systems, is, sadly, war. As we have seen in the many wars that have been going for the past 30 years, there has been a growing use of unmanned systems (air land and sea) to keep humans out of dull, dangerous or dirty environments. The war in Ukraine has catapulted hobby drones and the use of FPV techniques to conduct a new type of warfare. This has both reduced the cost of these weapons systems and allowed huge advances in capabilities and methods of use that, sadly, only wars allow. We can expect that the fall out from the use of drones (land, sea and air) will be greatly increased by militaries around the world. What happens in in the military world derisks civil use of these vehicles. You are making the classic mistake of thinking about drones from a model aircraft viewpoint. You need to look far wider and realise that there are real economic advantages to the use of unmanned systems in everyday life. I give as an example the use of drones to check crop health in arable farms. This can be used to determine whether the crop is diseased, the extent of the problem and how well the remedial action has resolved the problem. That, of course, puts drones next door to many of our flying sites. Transmission line inspection is another huge money spinner as it avoids the use of expensive rotary or fixed wing assets. I hope that helps those who are stuck down the "I just want to fly my model aeroplane without outside interference" view. It's about a far bigger picture. On that note, I shall disconnect from this thread as I'm wasting too much of my time fighting past battles.

Since no Government has ever managed to do that and they have thousands of civil servants to draft legislation why make such a song and dance over a relatively minor issue. There are 3 full time staff in the BMFA and only 1 who is responsible for dealing with this matter. He's already explained that he made an error. It amazes me that all those who complain can even manage to put a radio controlled model aircraft together let alone fly it yet can't manage to take either the RCC or DMARES test without making a great song and dance about it. Just get on with it and stop being so precious please!