Peter Jenkins

Posted by Phil 9 on 10/09/2017 00:38:48: F3a models plans seem to be thin on the ground. The are classics designs available but can anyone point me in the direction of some modern designs. It is not for completion so does not have to be sate of the art Phil, try posting on the GBR/CAA forum. That is an F3A specialist area and you might get some help on there. I know of at least 2 own built current F3A designs that are being flown in competition today.

Posted by Rob Buckley on 30/08/2017 21:37:18: Don't forget, it's not just the BMFA doing the lobbying. True, but it's usually the BMFA, the largest of the model flying groups, that get's the blame for not doing this or that. Incidentally, the BMFA is the largest of the Air Sports groups in the Royal Aero Club. The next largest is the para gliding movement I believe with some 7,000 members vs the 36,000 in the BMFA. It will not surprise you, Erfolg, that I disagree with your view that this initiative by EASA will sound the death of model flying in the medium to long term. I think there is a far higher likelihood that the demographic make up of our hobby is likely to be a much greater threat. There are 3 salaried employees in the BMFA who could reasonably be expected to carry out Erfolg's suggestion that the BMFA should provide us with a pro-former to guide us all in the production of an effective response as part of the consultation process. The rest are volunteers some of whom are still involved in full time employment. So, be like BEB and look in the mirror and stop expecting someone else to do what you could, with a little bit of effort, do yourself. BEB has given us the location to visit to send in our views. Don't keep expecting someone else to do what you cannot be bothered to do. Edited By Peter Jenkins on 30/08/2017 23:01:58

I do a lot of trimming of F3A aerobatic models and I never use the dive test as I'd rather be going away from "terror firmer" when checking CG position. Rather just roll inverted and check how much down elevator is needed to maintain level flight or, pull to 45 degrees and roll inverted and check again. The other issue is to sort the engine/motor thrust line. Trim for cruising power and then apply full power. If the model climbs then add down thrust but if it dives add upthrust. I won't go into side thrust but that is just as important to get right. What you are aiming for is as little interaction from the application or reduction of power on the aircraft's flight path. That means you can open or close the throttle and know that the aircraft will continue on its existing flight path until speeding up or slowing down changes the aerodynamic loads on the airframe. For some, and I stress some, aerobatic aircraft, the other check that the CG is in the right place is if there is no control movement required when in knife edge - but that is for well designed aerobatic aircraft. The vertical dive in aerobatics is another way of tweaking CG but once the aircraft feels right as regards CG then I usually mix enough down elevator to come in at fully closed throttle to give a vertical down line - in still air! In the real world with wind you usually need to adjust the flight line with a tad of up or down elevator to achieve a vertical downline. Just my way of doing things.

Best to use Gorilla glue or other similar foaming glues for fitting pin hinges (Robart type). The hole doesn't need to be a tight fit as the glue expands to fill the void. Never had a Gorilla glued pin hinge come out! Getting them aligned both in the vertical and horizontal is vital smooth movement. If you glue the hinges into either the fixed or moving surface first and then check alignment you can correct by cutting the offending hinge, re drilling and re-fixing. Once one lot are fixed then offer up the other surface and when satisfied, apply the Gorilla glue - sparingly!

I remember reading somewhere that most noise generated in model aircraft - metal to metal connectors, ignition systems, electric motors and many others - all ceased having any effect above 300 mHz. That would put both 27 and 35 mHz at risk but not 2.4 gHz. This fact is what drove the take up of electric powered bnf aircraft as well, of course, of vastly improved battery technology.

BEB I take your point. However, let's look at the existing wording in EASA's proposal: In some MSs (Member States), model aircraft operations are clearly defined and regulated by established model clubs and associations, in accordance with the regulatory framework of their NAA (CAA in the UK). These national regulations are mostly considered to be fit for purpose by both the remote pilots and their NAA. And: The main consequence of this issue is the barrier to the market. If model aircraft would be required to comply with the same requirements mandated for UAS, they could be even prohibited or at least a disproportionate burden could be imposed on them. For this reason, some special alleviations need to be identified for this aircraft category. (My emphasis) EASA is clearly flagging up that they think that the current situation in some Member States is perfectly adequate. They go on to say that allowing a fragmented approach to legislation i.e. left to the Member States' NAAs, there might be some who would impose disproportionate burdens on the model flying world. I'm with you if your point is that we, the model flying fraternity in the UK, and I hope across Europe, need to write in to EASA to say that we agree with their approach that the UK CAA's approach to regulating model flying is "fit for purpose". We should seek to have the issue of allowing new Clubs to be formed that would not be prohibited by legislation focused on "Grand father" rights. Not to do so would ossify the model flying fraternity in the state it is in at the point legislation is enacted. EASA in their document pays tribute to the impact of model flying on the greater good of the aviation industry and that is something that they see continuing. The issue of the lone flyer is going to be difficult to deal with but we should look at ensuring this can be dealt with by allowing new "Clubs" to be formed and old ones to be dissolved as may sometimes be the case - for example when a flying site it lost because of noise or other considerations. I think it behoves us all to take a positive approach and to go back to EASA with specific points that we wish to see identified as necessary and sufficient to enable model flying to continue along its existing course where we have many years of established operation and a good safety record. We should recognise, however, that there is a limit to the freedom we all want with the need to ensure safety of full size aircraft and indeed of ourselves from operators who masquerade as model flyers while failing to live by the standards of the established model flying community. To fight against such "infringement" of our rights would not be helpful for 99% of model flyers. I asked specifically what we should be drawing EASA's attention to and you have identified one. As regards one I can think of it is the potential height limitation of 120 mtrs. I fly F3A aerobatics where the top of the box is 260 mtrs. This is an international standard set out by the FAI and reading the story so far, this seems to have been taken on board by EASA. Clearly, thermal soarers will exceed this height quite handsomely so that is another point that needs to be flagged up although I can see that even today having a large model glider well into full size power flying territory can lead to problems although I've not heard of any to date. Full size gliders are notoriously difficult to see from other powered aircraft especially end on where they have a very low cross sectional area and are predominantly white - model gliders being significantly smaller will pose even greater problems. As ever, it requires us to exercise our judgement as to when to use our freedoms and when to defer to our full size brethren. I am quite certain that the BMFA and Dave Phipps has made all of these points. Remember that Dave has also been helping to represent the FAI and Europe Air Sports. We also have the 500,000 modellers in the EU forming into a pan-European movement where Dave is also active. I guess my point is that rather than just posting gloom and doom views which are not always based on what has actually been published and not insisting that EASA is staffed by a bunch of incompetents, it would be a better to think about specific issues and raise real points rather than vague comments along the lines of "we're all doomed". What precisely are the points that we need to make to EASA based on real issues. Condense those into concise arguments and send them to EASA.

BEB, having re-read NPA 2017-05 (B), it is quite clear that the lobbying from the model aircraft world has been recognised. Section 1.2.4.7.3. deals specifically with model aircraft. The introduction to the section states: In some MSs (Member States), model aircraft operations are clearly defined and regulated by established model clubs and associations, in accordance with the regulatory framework of their NAA (CAA in the UK). These national regulations are mostly considered to be fit for purpose by both the remote pilots and their NAA. Based on the replies provided by model aircraft associations, a total number of 1.5 million model aircraft across the EU could be estimated. The text continues under the Consequences heading as follows: The main consequence of this issue is the barrier to the market. If model aircraft would be required to comply with the same requirements mandated for UAS, they could be even prohibited or at least a disproportionate burden could be imposed on them. For this reason, some special alleviations need to be identified for this aircraft category. (My emphasis) The document continues with the view that if there is no EU-wide legislation on this topic then National Aviation Authorities (NAAs) would continue to implement rules that would be different and, in some cases, overly restrictive. In our case this is referring to the status quo with which both we and the CAA appear to be quite content. Please explain why a further response to EASA is likely to result in any further relaxation in the proposed rule making at this stage?

Erfolg, why do you quote selectively from Dave Phipps' news flash? The detail you omit to quote from I reproduce below, again from the very same article that Steve J referred to above, namely: The DfT proposals generally align with those developed by the European Aviation Safety Agency (EASA). The general principle is that (for those operating outside the framework of an established model flying association) the regulations for unmanned aircraft will be more restrictive than those currently in place with additional requirements for training, registration and a 400ft/120m height limit. This is comparable with the ‘Open Category’ requirements proposed by EASA. Within the EASA proposals, established model flying associations would operate within the ‘Specific Category’ under an authorisation granted by the Civil Aviation Authority (CAA) which would essentially allow us to operate as we do today. The DfT’s proposals do not change this. Essentially, the CAA would issue us with an authorisation (or exemption) defining our agreed operating parameters which would reflect how we operate today (including operations above 400ft/120m). I hardly think that your claim that no one is doing anything holds water but no doubt you will seek to split a few more hairs to explain to us why this is the case. Peter

If you are interested in flying at the new National Centre and in getting coaching in how to fly precision aerobatic manoeuvres correctly, you can kill 2 birds with one stone on Sep 6th. The GBR/CAA is running an Introduction to Aerobatics Course at the National Centre. Cost will be £12 per head and will include refreshments and sandwich lunch. Full details are here.

Thanks for your virtual support Phil. Just need some actual entries now otherwise with only 3 signed up we may have to cancel this due to lack of interest. In previous years, we've never had fewer than 9 entrants. I hope there will be some take up soon.

Gary, this may be of no use to you given you'd need to buy a JR XG11 Tx and Rx. The XG11 Tx has a 4 aileron setup that, once selected, just works a treat. It may be that the DSX11 or 12 have this function as well. Perhaps a DSX 11/12 owner could chip in on whether these Tx have a 4 aileron wing as a selectable setting.

I will be running a New (to aerobatics) Pilot Open Day on Sat 23rd September at the Bury Model Flying Club (near Bury St Edmunds not the Bury in the north). The aim is to help pilots interested in improving their aerobatics by coaching them to fly the GRR/CAA Clubman Schedule. We try to fly 4 rounds with the final round being a low key competition which is judged. If you don't want to be judged then you can just fly the 4th round as a coached session. Thanks to the BMFA and Bondaero, we are offering a prize of a Skylark S (EPP foam aerobatic machine) which just needs your Rx and a 3S 1800 mah flight pack to be ready to go. Currently, there are some 9 places still available. If you would like to take part or to know more about the event then PM me with your email address and I'll send you the briefing note and entry form. The cost is the princely sum of £5. Peter

Posted by Martin McIntosh on 09/04/2017 20:38:42: Peter J., How does that motor compare with say a YS? Martin Apologies - I forgot to bookmark this thread and have only just come across your post. I've never flown a YS powered bird (shame) but I would say, that the YS may just have the edge but then again, the DLE is still quite new. On the other hand, the DLE is a lot cheaper to buy and run. The YS does sound better although with a JMB canister, the DLE is quite acceptable. Peter

I have checked this on several occasions with checking the charge going back into my Rx battery which is a 2 cell LiPo of 800 mah capacity run through a voltage rectifier to give either 5.9 or 6.1 v to the Rx and servos.. I fly F3A and the current FAI P schedule results in a consumption of 85 mAh per 8 min flight. I used to fly 3 flights and change the Rx battery but I am now confident enough to fly 4 (occasionally 5 flights if not flying a schedule) with the same Rx battery. That equates to around half the available capacity of the pack. I use 5 digital servos in the model which is a 2 mtr class model weighing 5 Kg. There is very little stick banging but a lot of small movements most of the time during manoeuvres. There are 17 manoeuvres plus landing and take off per flight. On a petrol model I have now standardised on using 2500 mAh LiFe batteries for Rx (and servos) and the ignition. I feed this directly to the Rx and to my JR servos which are perfectly happy with the top voltage of, usually, 6.6. The JR servos are not happy with a 5 cell NiMh as their voltage fully charged takes them over 7 v. Hope that helps.

Hi Adrian, well done on a successful maiden. You say that when inverted there was a slight tendency to pitch nose upwards. That's caused by your CG being behind the stable point. You also say that KE does not require any corrective aileron. I would ask if the aircraft pulls to the canopy or to the u/c. Moving the CG will affect this issue but if you are focusing on precision aeros and not 3D, you would do better to move the CG forward (shifting the flight pack is all that's needed) a little at a time until you need to maintain a little forward pressure on the stick when inverted. You could also investigate what effect moving the CG even further forward has - does it improve the handling or does it make it worse. The other indicators of an aft CG is a slight delay in spin recovery or, if you use opposite rudder to stop the spin, the potential for a spin in the opposite direction. CG position is the single most important trimming tool we have at our disposal. Every trim step after that needs to be repeated after moving the CG as this affects everything else. If you have not seen it, the GBR/CAA trim chart gives some useful advice on trimming. You will find it here. That also goes into how to ensure a vertical downline as well as a vertical upline. It generally takes about 20-50 flights with an aerobatic aircraft before the trim is sorted and it flies like it's on rails. It's worth the effort and don't forget to return to it if the aircraft starts to misbehave at any time. Have fun and enjoy your new aerobat.

In my experience, a light landing that causes significant damage has usually been preceded by a number of "arrivals" that did the real damage. The structure finally gives up the ghost when a slightly less than perfect landing is made and everyone is amazed at the amount of damage from a very slightly heavy landing. Same applies to full size when the guy who failed to own up to doing damage to the aircraft, because it isn't visible on the walkround, passes the price of his misdemeanours onto the next unsuspecting pilot!

I'm sure you won't need luck for the maiden. Maidens with these birds are, provided the CG is there or thereabouts, usually pretty straight forward. The fun starts after that with getting to the optimum CG before moving on to the other trimming points.

One needs to differentiate JR 2.4 radio from the Spectrum technology and JRs own DMSS or XG range of radio. I started as a Futaba person but when 2.4 appeared, a month after buying a FF9 (argh!) I waited, and waited and waited for Futaba to produce a 2.4 mHz module. In the end, I went for a JR DSX9 set on the basis I could buy cheaper Spektrum Rxs as well. That resulted in me losing 2 models due to brown out - it took almost 3 secs for the Rx to come back on line with the then technology. When JR launched the XG series I went for the XG11 and have been extremely satisfied with it. What I did notice moving from Futaba to JR was that programming the Tx, for me, was a darn sight easier with JR. True you couldn't use any switch for any function but then I've never found that to be a problem. Others might value this flexibility but I found it confusing and difficult to use. I find that the Tx mixing capabilities are fine for all the flying I do including flying F3A competitively. As ever, one has to ask on fora for advice on how to achieve the really useful mixes since the JR instruction manual is like most others in being useless for anything other than the basics. If JR decide to leave the model world, which I guess is looking that way, I will not feel I need to change until things start to break. At that point I think the Jeti radios will have another customer especially given the level of telemetry you get using a Jeti Mezon ESC. Oh, I should say I started by building a valve carrier wave MacGregor radio. The Rx battery was huge but nothing like the Tx battery! Then progressed to building my own Remcon Quantum 6 - but only one servo amplifier as I found it very fiddly going. My Quantum 6 was a disaster as far as range went and despite taking it back to the Remcon I was told it was fine. I never flew it. Finally, I bought a Futaba M series. Lovely piece of kit back in those days but sadly I'd moved on to full size flying my then and never used the Futaba although I still have it. Edited By Peter Jenkins on 02/08/2017 23:51:35

The wiring setup for the ESC to battery connection is below. The ESC is a Jeti Spin 99 Opto with no BEC output. It is almost universally used in F3A as you can programme in the amount of braking in the downline using the Jeti Box to set up the parameters. For powering the Rx and servos I use a 2S LiPo of 800 mah which is good for 3 flights - usually more than 50% remaining at that point. The battery is plugged into a Powerbox Digiswitch which provides a regulated 5.9 volts to the Rx and servos. I have 3 standard BLS servos (rudder and 2 ailerons) and 2 mini servos (elevators). In my biplane I have the same set up but with 6 mini digital BLS (one per aileron and elevator) and one standard BLS (rudder). The standard servos are 11 Kgcm while the minis are 5 Kg cm. Again, a standard set up in F3A, The aircraft are 2 mtr standard F3A weighing in at 5 Kg with batteries. The photo below shows the Rx battery setup. Hope that helps.

Hi Adrian, Here's what I use for connectors. They are HXT 4mm bullet connectors which I separate into 2 separate connectors by cutting through the plastic joiner. That allows them to be used to plug together in series for flight and in allows them to be charged in parallel. You can buy them here.  They, the wiring and ESC are good for 90 amps. The batteries connected in series look like this. I just plug the anti spark lead into the battery positive plug and then the ESC +ve plugs into the spark arrestor itself.   Edited By Peter Jenkins on 02/08/2017 23:33:59

I'm with Steve on the UBEC. No one I know of in F3A uses anything other than a battery and switch to power the Rx and servos. The most popular switches are the Powerbox ones which provide a regulated voltage output between 5.5 v and 5.9 volts. That means you can use a 2 cell Lipo. I use an 800 mah 2S LiPo and that's good for 4 x 8 min flights, although I usually change batteries after 3 flights. The Emotec magnetic switch is also a popular choice. Not many use mechanical switches. There is also the Optiguard back up battery which some are now using to guard against Rx battery failure. I have to say that I don't use that particular back up. Keep the component count down and the wires as short as possible. I can only speak for F3A models but I've always seen short battery leads and standard length ESC leads used. If the model has been designed for electric power then the battery position will have been chosen with lead length in mind. Hope that helps.