John Bisset

Very nice. Piers - I recall them being called the 'de Havilland Ground Gripper' too ! I believe it was one of the very few aircraft certified for selection of reverse thrust in the air. On approach to Dyce after they selected reverse thrust on short finals to 36 there was no 'go around' option after that, which is partially why one ended up slightly over-running onto the grass. A very solid and well engineered piece of kit. Pity BEA's insistence meant it was smaller than first planned. John

Posted by kc on 24/06/2017 16:44:52: Digital trims are horrible things! Manual trims are much more controllable ...... I reckon many people would pay to have manual trims on a 2.4ghz set at extra cost! I am glad I'm not the only one who thinks that!

Glad all is now well. The wee beats does fly nicely, though I haven't yet played much with aerobatics, something the full size was particularly very good at. I have sometimes used my thumbs too - strangely that occasionally feels more like flying full size to me. I wonder too about first flight losses - personally I tended to fly any new model (in the old days with simple Futaba txs) using high throws with the option to flick down to half throw later. That helped cover the occasional CG error requiring lots of elevator and usually meant I could get to height quickly to allow me time to sort out my reactions and decide on throws. Incidentally I find trimming on modern radio systems awkward and not intuitive. Without any feel for how far the trim has travelled I have no 'feel' for what is happening. Glancing at the tx screen is NOT a good idea- loss of visual picture is bad news. This is an example where 'advanced' technology works against us humans. Same is true on some modern aircraft power levers, which in some modes do not move when the ECU adjust power. Aargh - engineering; sometimes two steps forward but one back ?.

Hi Peter, I have been flying the ST Salto using a Spektrum DX6 with the throws as recommended by ST. It is very maneouvrable like that - I like to use my thumb and forefinger on the stick and fairly gentle movements. Take-off and climb is OK on full throw. I did set up my transmitter so that I could switch in half rate for elevator and aileron. The aileron half setting is fine for smooth easy rolling maneouvres and balances well with rudder. Using the half elevator setting works fine for gentle flying but I find it better to take it out for landing, to give me more elevator authority. That said, my approaches are apt to PIO a bit because of the sensitivity. The Salto tends to mush a bit at the stall, so approaches on the slow side don't work too well. I haven't got the hang of that yet - like the real thing she also glides well, so my approaches are on the shallow side. Hanging the motor out, but not running, adds drag - just like the real thing ! - which helps. Airbrakes would be nice; maybe when I get clever with the machine I could split the ailerons four ways for some crow braking! I hope that helps. John

Excellent stuff - lots to think about. Thanks all. Martin, I understand and agree. We have some fun playing with different prop types and pitches in full size as well. It is more of an art than a science at times, though 'cheating' with a VP prop helps ! Sometimes changing the prop to reduce noise level is worth a small sacrifice in climb rate. The 'scream around the sky' types are always with us. Personally I like a more relaxed style, both for model and full size. - and Col Aresti never meant people to fly his diagrams as drawn, with square corners. He flew a lovely aeroplane, gracefully. I admire the Extra 300s and similar machines with their extraordinary capability and gut-wrenching maneouvres, but for me 'LAROSA' sums up my aspirations well. Cheers, John

Very true Allan, though that is as much to do with insurance outfits trying to find ways to avoid payment than safety, necessarily. The risk averse society? If the BMFA wanted to be really clear or definitive about that, they'd have worded it differently and/or added explanation/justification to add emphasis. Plus there is the small matter of how and where the speed is measured, by whom etc. ! Personally I am cautious at these speeds when flying full size light aircraft (something I should be doing this weekend), and my models would have a hard job getting back upwind at that speed. Flying a pattern would be - um - challenging. On the plus side, think what the downwind passes would look like ! John B

Thanks Frank, John and Pete for the latest thoughts. I shall try the step down to 2S Frank - I want to get some smaller, lighter batteries and motors for later projects. Good point John - handy the efficiency just evens up the conversion! Useful. Pete - that will help when checking alternative prices. As a Scot I do like a bargain ! John

Thanks Ray. Some good information there. I am pleased to see that my thinking about my conversion of an old Wot4 is mostly confirmed by the author. Those servos look rather familiar too ! Regards, John

It's the likely strong gusts which would worry me more than the base wind speed. I suspect the microlight folk will be reluctant to fly the full size if the gusting is more than 25 knots. Certainly at 30 knot gusts I'd stop, even if there was excellent wave above! The risk is mostly of wrecking beautifully built models. Like John, I wasn't aware of any rule or law which specifies a wind speed. It is normally up to the judgment of the pilot as to when he/she calls it quits. (Always remembering the old saw: "It is better to be down here wishing you were up there, than up there, wishing you were down here". True for full size, and for much loved models too) The forecast may prove pessimistic, of course. Only one way to find out... Cheers, John B

Thanks all. I realise I should not have posted late at night without further thought and mulling. I was aware of the effect of prop match and should as a minimum have allowed a factor for prop efficiency. Tsk. I suspected that a poor prop match was part of why my previous Nicad and 540 motor combo was so marginal. BEB – I shall have a look for your article. Which issue was it in? I don’t get every issue, partially due to my rather random bookshop visits. (Yes, should subscribe!) Somewhere I have an old strobe light, which could be modified for checking prop rpm. Another little project beckons… Frank – I hadn’t heard of Drivecalc. I shall try it first since it looks more approachable. Maybe Ecalc later. Pete – Yes, the beast is well overpowered. I am running her around at less than half power, except for the take-off zoom climb. Happy with that, since it eases strain on the system, but I want to get a better handle on all this for later work. I fly full size motor-gliders, some of which have marginal take-off climb rates, so having handfuls of excess power instantly available is a pleasure, as wellas being useful when shaking off years of rust in my model flying. Which wattmeter do you recommend? I mentioned the Turnigy because I thought 180A would give plenty scope, and it seems readily available. I have a number of i/c models which I may convert to electric, plus some kits to build or complete. Whee. Those are old style builds and will be heavy compared to much modern stuff. (Original Wot4 Mk1 and Acrowot for example) For the larger ones having good estimates of power values will be helpful. It’s going to be a while before I get down to smaller and lighter weight work; I have a number of Futaba S148s ‘in stock’ plus a few Hitec S101 Mini servos. Those ‘minis’ look quite large when I peek into the modern foam ready builts. Cheers, and thanks again John B

Comments and advice/correction please folks. I am now flying an electric powered motor glider, which I have uprated from its previous Nicad battery and 540 size brushed motor. That arrangement only just flew; the new fit really is impressive, and I am wondering if I have overdone the power a bit. The set up is – a PO-3535-1090 motor from 4-Max driving a 10 x 5 prop, with a 40 amp ESC and a Turigny 3S 2200mAh 20C to 40C LiPo battery pack. The model is a Merlin which I built many years ago. Total weight is 960 g or 2.2 lbs ready to fly. Am I right in thinking that I am probably getting around 330 watts power out at the nominal maximum continuous power setting? Or since it is a 20 to 40C, should I atke the average of 30C output,? That would suggest around 450 watts, which would be a significant excess of power! 2.2A x 20 x 0.66 = ~30 amps 11.1 v x 30 amps = ~330 watts Are my calculations approximately right? I am tempted to buy a wattmeter –the Turigny 180A meter seems like a useful purchase. Does anyone have one and can they comment? Thanks & regards, John Bisset

I think the 'BP' in that name may mean 'British Pharmaceutical', implying to meet those standards. Though Shell & BP advertised their aviation fuel under the 'Shellmex BP' title, since those two oil companies had a tie in agreement. John

I'd agree with Braddock VC (Ah - the old stories from many years ago) that castor oil is an excellent laxative, That was why some early aviators had digestive problems... Castor oil does form a glaze on metal surfaces at high temperatures. I recall that being viewed as a benefit for some model engine use, to improve sealing. So, maybe not entirely superseded by synthetics.

If I recall the early discussions on this correctly, it should save a great deal compared to conventional rocket launches. It is the first few thousand feet that cost a lot to get above and a great deal of the initial weight is used up accelerating fuel needed for that first segment of climb. Launching from 30,000 ft plus at several hundred knots provides an excellent flying start. I think when the rocket is also attached the total mass will be greater than any other aircraft has reached. Impressive.

The comment about EASA, and possibly as a result the CAA, viewing a 'club or association' as something at National level rather than at local level, strikes a chord. In the gliding movement I believe the CAA tends to talk directly to the national association, the BGA. It does not normally discuss with individual member clubs of the BGA, to the best of my knowledge. In effect they devolve the detail of the management of sailplane flying to the BGA and discuss/agree only the broad issues. If problems arise, it will be to the national association they go first. I will check that this weekend. Regards, John Bisset

‘BEB’ - and probably ‘Steve Houghton 1’. You might like to think about working up a Risk Assessment. It is very probable the CAA would want to see that given that in each case you are talking about common land with routine public access. If properly done there should be scope within that to mention the years of accident/incident free time, although of course that of itself is no assurance of safe operation! It may be useful to back up your assessment of risk levels and/or mitigations suggested or in use. No doubt there will be groans at the thought of doing an RA – understandably since they are rather oversold at times – but they can be useful if done sensibly and simply and I expect would be of help when dealing with the CAA.

Thanks both. Yes, the failsafe of low throttle setting plus use of a Tx switch to inhibit is working. Having dealt with quite a few hand start - 'Armstrong Starter' aircraft over the years I am very wary of propellers of all sorts. Which hasn't prevented me being 'bitten' or perhaps nibbled by both model props and the fullsize, fortunately both firing at low power settings.

Posted by Keith Lomax on 25/05/2017 15:26:05: “The CAA will take the route that requires the least on-going workload to administer.” True – they are very short staffed now, and have fewer folk interested or knowledgeable about aviation. Ability to write unreadable documents and create ever harder to fathom websites – sadly in that they appear to have more expertise than ever ! Unfortunately that can mean that when useful changes are made it can be hard to find out the detail about them – if some recent examples from full size light aviation are typical. They mean well, but… Like several here, I am very concerned about the age limits. My son learned at around 10 years old, after building his own model with minor help from me. (Getting the wings true) I saw no problem and there were several others at our club of similar age. In full size gliding 14 years old is the minimum solo age now, so no good reason for 16 in this hobby. The probable restriction on offsite flying is another major worry. The comments made about the 'U space'. This is a major worry to us in full size aviation too. Commercial drone usage below 400ft may sound safe but given how much trouble we have ensuring existing legitimate airspace users area aware of light aircraft and gliding sites and their circuit patterns/traffic zones, trying to ensure safety in the circuit with drones roaming at will could prove very challenging John

Trevor and Mr B. Thank you. That confirms things - I was over complicating things with the 'binding'. Silly- I realise I was thinking in terms of the receiver getting updated instruction from the Tx as used to happen in some old style drone aircraft (the full size ones, not models). Of course, it makes sense that, just as with the elevator/rudder mixing. All the fancy work is done at the Tx end. Clot. Essentially 'binding' is just like swapping crystals in the old set ups. Also your comments about being too close are most useful. That might well explain what seemed to be random 'bind fails'. Shall stand back further. I am most grateful for your help. Grr - this really is 'old dog new tricks'. Most annoyed with myself that ingrained habits and assumptions are proving harder to set aside than I'd thought ! Onwards. It all works now, so time to go fly.

Thank you Trevor, and Colin. Yes, I seem to be getting 'bind fail' messages quite frequently after making some attempted changes to the setup. Interesting that this is so unusual for you two. Trevor, it is occurring after making changes, when trying to check what the effects of the changes are. When I revert to ‘known configurations, as is well and binding goes as it should. I have carefully checked again what I am doing when binding, with respect to what the manual says – all seems OK there. I shall also check at my club soon; several folk there run DX series radios. I do hope this is not a transmitter fault Colin – intermittent problems are the very devil to prove! Presumably few of your clubmates will be making alterations to the System Setup at the field, hence not many fails. I am inclined for now to believe it is due to ‘operator error’; in my experience that was the commonest of faults! Plainly the wording and logic of the manual and the programming ‘does not compute’ for me ! Mind you, I do go back to the days of analogue computers… Thank you for the comment about ‘Flight Mode’ switch Trevor. That is something I have not got my head properly around yet; what exactly is ‘Flight Mode’ and how do I set it.? The old Futaba FP 6 series has two switches just above the sticks which give half rate on elevator and aileron respectively. Very handy, and that is what I am trying to set up on the DX6. And failing, so far. (‘Flight Mode’ sounds to me a bit like the very grand sounding ‘Ground –Flight’ switch in old British aircraft – a large and impressive bakelite contraption, usually mounted prominently on the panel. It looked worryingly important, but in fact was simply an electrical isolation switch to protect sensitive electrics during start up!) Another try. My Flight Mode was inhibited – I reset it to Switch C, which told me ‘Enabled Flight Mode 2’, whatever that means, and then showed ‘MODE 1 FLIGHT MODE 1’ at the bottom of the screen. I tried to bind after that -got a ‘bind fail’, so I reset to inhibit in Flight Mode. All well again, system still happy to bind with the previous config’n. So plainly there is something else I need to do when tinkering with ‘Flight Mode’. Honestly, if this model wasn’t a V tail I’d just drop back to my old Futaba and go fly. Part of the reason I bought the wee beastie was to see how they had modelled the elevator/rudder mixing box. Most disappointed to find they hadn’t. John

Hmm. Some progress but rather one step forward, two back at times! OK - another question. I thought I'd set up my DX6 so that I had the ability to rapidly change rates for aileron and elevator to half throw. (I have that on my old Futabas - very useful when doing test flying) I tried what seemed like the correct settings page – on ‘D/R and Expo’, but changing the switch settings – to use switches C & F for elevator and aileron rate change respectively,- and setting /or the ‘dual rate’ values kept causing ‘bind fail’ responses. So, I must be doing something wrong. Help – anyone know what I should be doing? John

Thanks Colin. I shall carry on trying to get the hang of the DX6 first then. I eventually found that changing 'Throttle' in 'Trim Set Up' screen to '3 -pos digital' allowed the binding to go ahead correctly. That gave me variable throttle on the lefts tick and a safety switch override cur-off too. So that looks good, though I still don't understand that or what the other options offered really mean. I shall have to go through the set up processes and the various screens item by item, writing down as I go until I fully understand. Meantime, I can fly the beast, hurrah. (Pilots don't have to know what is going on behind the scenes...?) John

Thanks Colin, Ronaldo. I'm not there yet- still getting 'bind failed' in the power mode so I must have something set incorrectly. Grr. Shall persevere. It is so tempting to assume it is a failing of the equipment, but since I can get the system to respond under sailplane setup, though only with all or nothing throttle, clearly it's me. I have also just got access to a DX9 Ronaldo, so I may try that later. It sounds from what you say as though the DX9 may give me a variable throttle sailplane option. Oh for the old days of comprehensive manuals which exhaustively stepped through everything. Once I get the feel of the logic used here, hopefully all will be easier. Regards, John

Hello. I am a ‘returned’ modeller, just coming back to the hobby after 20 or so years away. This means that outrunner motors, LiPos and modern programmable transmitter/receiver systems are all new to me. I recently bought a Spektrum DX6 radio system – with an AR610 receiver. I also bought my first ever ready made machine – an ST Salto – as a bit of fun since I used to own a Libelle sailplane and the Salto was a V tail version of that. I also rather liked the pop up fan motor arrangement After some struggle with the, to me, unusual selection arrangements, I have the radio modelling a V tail sailplane and correctly providing the mixing required for the V tail. However, I can only get the system to bind with the throttle control selection set to a switch – most easily Switch A. That of course gives me only full throttle or motor off, no variability. If I try to bind with the throttle selection set on the transmitter to ‘throttle’, I get ‘bind fail’ every time, with no other information. Most helpful! Am I wrong in assuming that since the radio offers throttle control options in the set up, it should accept them? Or is the problem that the radio is ‘seeing’ a sailplane not a power plane? It is only while writing this that the possibility occurred that resetting the radio to see the Salto as a power plane may be the solution. Possibly my mindset in viewing the Salto as a (powered) sailplane and in thinking old style computer programming is the error. Any comments from more experienced folk will be most welcome… Meantime I shall try re-setting the radio. John