Airhead

Posted by Martin Harris on 30/04/2020 20:59:57: I have an international airport less than a mile from mine so my local park is a non starter... Ha! If you're a drone pilot, you will be able to fly over the airport for a whole week... and the world's press will turn up with lenses a yard long - yet no-one will get a single photo of you or your drone! (That's what happens isn't it?)

My sixpen’orth… Lifting of lockdown restrictions will be slow and steady with society’s best arguments (understandably) getting sorted first and unfortunately, model flying has a poor argument and being such a minority hobby, will be way down the list… if we’re on a list at all. And virtually no-one in authority gives a hoot for us, of course. It’s easier just to keep all minority groups under lockdown than sort them all out individually. I’m sure when (if?) we get our restrictions lifted, it will be on an “OK, finally the rest of you can get on with your lives again now,” basis. There are some good arguments here, John Laser says a slight easing could work and others say similar things and that we could all do things safely, keep apart at the field etc. but that won’t wash with the powers that be. Just because something can be made safe doesn’t mean it will be condoned. Look at the wealthy peeps that hired a private jet to the South of France a couple of weeks ago with private helicopters standing by to take them on to their villa. No doubt an eye-wateringly expensive trip that I couldn’t have underwritten that turned into a day out, they were turned back by the French authorities, “Allez back to Angleterre mes amis!” (Quite understandable and of course, the French do love a veto!) They may have been able to afford to be safe but they couldn’t be seen to do so when everyone else is tied down. We’re all in it together remember and just because we could fly safely and hygienically, WE can’t do so whilst other hobbies are under lockdown. It’s not as if we can claim we are out exercising, long tramp from carpark to flying line/top of the slope notwithstanding. Unfortunately, like Nigel R, I too believe there will be many, many more people die of this awful pox before we’re through – if we ever do get through – and I worry about my father who’s 96, so in the vulnerable category, and have already lost a biker mate with suspected C-19 at the tender age of 50. This virus is similar to the common cold and if it turns out that it mutates as readily as the cold and we can catch it again and again, we and the world are in a damn rotten and possibly permanent situation. On the question of when we will return to work, (I’m in the food industry so I’m lucky, I’m still working) the answer must be ASAP! But the question should not be, “When?”, it’s “How?” What you have to remember is the government doesn’t give a toss about 20,000 peoples’ deaths. It’s a mere drop in the ocean – we’re a nation of millions. As individuals, the members of the government WILL (probably) care and if they can do what’s needed with the minimum of death and suffering, they will but as an entity, the government is there to run the country and the country is presently getting a severe financial kicking. If governments could afford to care about people maybe we wouldn’t have wars, but they must worry about business, production, GDP, employment etc. That’s their job. It may sound harsh but it’s reality – if Boris could send 20,000 more people to their doom but get the country back on a stable, profitable but safe level with the majority of us employed, I’m sure he would. He’d need it NOT be known that that was how it was done of course, and I’m certain, especially having been through the virus himself, he would personally feel bad about the loss of life but his job is to run the country not save lives. His is not an easy position to be in. (OTOH, Maggie T would have done it with a grin on her face. She’d have sacrificed any number of people so long as it made her look heroic and didn’t cost HER anything.) In defence of the government – not something I say often – there is no ‘right’ course of action. Whatever they do is going to be wrong. If they bang a severe lockdown into force on day 1 and virtually no-one dies but the country goes to the dogs financially, everyone will say, “Oh the virus wasn’t THAT bad…” but if they keep the country buoyant and working but thousands more die, everyone will say that they should have introduced a serious lockdown. They can’t win. And we’re just minority hobbyists… neither can we.

I just came across this thread and I know this it's an old one and it may not interest anyone any more but just in case... Despite Robin's suggestion, this is not a Simprop Solution, though it does show a massive family resemblance. It's a Simprop Ventura. I know, I have one. Those weird sheet wing tips give it away. See box pic below. If anyone is interested in buying mine, I DO need some space...

I don't know what Coc is - or where to find it. I HAVE searched around and found the rule that outlaws asterisks (which I hadn't seen before) and I apologise. Unfortunately the joke needs the word or it doesn't work. I cannot now edit or delete the post - maybe a moderator will do so but I'll remember that rule for the future.

Don't forget that being able to tell homophones apart can make the difference between... knowing your s#!t... and knowing you're s#!t !

Our transatlantic cousins are, also (I believe) the origin of ‘verbing nouns’ (itself a case of verbing, – where a noun is used as a verb), the classic example being “access”. You cannot “access” something. You can grant or gain access to something but “access” is a noun, not a verb. (To make it clearer,“access” means “admission”. You cannot admission something, but you CAN grant admission or gain admission.) You may have noticed that I’ve invented a new noun; the word “re-noun”. Well, it doesn’t stop there. I’ve verbed it too… “Re-nouning” is the new black! How about the ubiquitous use of “laying” instead of “lying”. You don’t have stuff laying around, you have it lying around. Don’t tell your dog to “lay down”, tell it to “lie down”. Yesterday it lay down but today it lies down or is lying down. You can lay the table or lay your gun on the ground. If you’re a chicken you can lay an egg, but once that process is finished the egg is lying in the straw, not laying there. FlyinBrian, in defence of people who use the expression “little baby” (you say, “are they all not little” by which I guess you mean, “are they not all little?" well, babies DO come in various sizes and I’m sure you have at some stage called someone – or been called – “a big baby”. “Big babies” is an accusation that will probably be levelled at those of us in this thread by those who don’t care about the English language. Punctuation is a bone of contention. Legal papers are written without any because the insertion or omission of a comma for instance can change the entire meaning of a sentence. For instance, the book title mentioned above, “Have you eaten Grandma?” has a completely different meaning to “Have you eaten, Grandma?” People, even English teachers, say that punctuation, spelling and grammar don’t matter so long as the writer is understood, but isn’t it easier to correctly understand someone who punctuates and spells correctly and who uses correct grammar? Oh... And while I’m about it, the expression is not, “Each to his own”…, it should be, “To each, his own”. “Each to his own” just doesn’t make any sense. I’d better stop now or I’ll be here all night…   Edited By Airhead on 13/03/2020 16:57:26

David Davis, There are many examples like your kiLOmetres. COMpact discs for instance, are American… in England we should have comPACT (meaning small) discs. It’s called putting the emPHAsis on the wrong sylLABle. Among many other expressions that grate and/or mean nothing, at work there is a common expression (generally among managers); “Going forward…” Well, time being what it is, we can’t go back – unless Doctor Who is real. I believe the expression should be, “In future…” My teeth also grind when I’m requested to send or forward something “to myself” Aargh… have these people never heard of the word “me”? Only I can send something to myself. YOU can’t send something to myself, only to ME! How many people don’t know the difference between “too” and “to”? I remember in one no-longer-with-us modelling magazine an article titled, “How Too Land” with the heading emblazoned in inch - or two - tall letters across the page. You may be surprised to know that the article was written by the editor, no less. You’d think an editor of a national magazine would know the difference between “to” and “too” wouldn’t you? – I think I knew the difference before I started school! Americans are an easy target when it comes to expressions – so let’s have a go… Have you noticed that they often get a noun, turn it into an adjective and then convert it back to another (incorrect) noun? The example I often quote is a guy on TV describing one of his fellow soldiers and relating that the chap exhibited “great courageousness”! Eh? Whut? You had a noun – ‘courage’, made an adjective from it – ‘courageous’ – no probs… but then, if you need your noun again, it’s still there. You don’t have to create a new one! I’ve heard many of these re-nouns, “skilfulness” instead of “skill” and many others. Insidiously, these will creep into the wider world if we’re not vigilant. Keep a lookout for this sort of thing, you’ll soon spot plenty of examples and soon after you’ll find yourself yelling at the telly. Like I do. I'm running out of space so I'll finish this rant in another post...

David, True, at the low speed of a J60 the wheels and wire of its u/c would generate only small amounts of drag but at the airspeed of the average J60, so would a barn door! Nevertheless, I merely picked on the u/c as it’s easy to remove. If you would like to build a modern aerofoiled, high aspect ratio, laminar flow wing with hidden fixings then be my guest; I imagine it would take longer than dropping the wheels. But ultimately it’s a percentage thing isn’t it? What percentage of the drag is caused by the u/c? Wire create a surprising amount of drag when going sideways through air (control-line speed guys find an entire wing is less draggy than a skinny bit of wire measured in mere thou which is why their entire wing is on the handle side of the plane’s fuselage) and wheels will obviously vary. The old scrawny discs that were/are used on rubber models will create considerably less drag than fat old Trexlers. But as I say, I just picked the u/c as being quick to remove/replace. And of course, I wouldn’t want to remove or even reduce the 60’s delightful quirks. You obviously know something about aerodynamics – a subject for endless debate. It’s still not decided among aerodynamicists how planes fly... Bernoulli theorists will argue one way, Newtonians another and don’t get me started on the Bound Vortex theorists! I am certainly no expert, I just find it fascinating. I used to enjoy Alasdair Sutherland’s column in RCMW and my monthly treat was to read the problems sent in by readers and attempt to work the causes out myself before reading his replies. I had my successes. The adage is, “it’s not rocket science” (or salad as my attempt at humour had it in my last post) but rocket science is easy – you just lob as much as poss, as fast as poss, out the back! Now, to explain aerodynamics you really need a rocket scientist. Or a brain surgeon. Anyway the following is intended for some of the other readers of this thread more so than you as I suspect you already know it… You say, “Tight turns require too much bank angle on such a big dihedral RET model and she not only looks "uncomfortable" but responds by gently slowing down and sinking.” Firstly, coordinated turns require the same angle regardless of whether the plane is R/E or aileron equipped, but imagine your plane is banked at 45 degrees in a certain turn… The lift generated by the wing is inclined at 45 degrees too so to stay at the same altitude, you will need more lift. How much more? Well, the vertical component of the lift is equal to the horizontal component (that’s why I chose 45 degrees – to simplify the maths!) So if you draw a horizontal line to indicate the turning force and a vertical one to indicate the lift force (the same length as it’s the same magnitude), the lift required will be proportional to the hypotenuse of the triangle formed. And the length of that will be the square root of the sum of the squares of the other two sides and we know this ‘cos of that old bubble, Pythagoras. (This would be so much easier with a diagram!) For simplicity let's give the horizontal and vertical forces a magnitude of 1. So 1 squared equals 1, plus another 1 squared – again 1 - makes 2. The square root of 2 is 1.414 so you will need an extra 41% lift to maintain height in a 45 degree bank. This is because your plane is accelerating. No, it’s not going faster, but it is changing velocity because velocity is speed in a given direction. Change speed and you accelerate, yes, but a change of direction is a change of velocity too. This is why you should not only lean back on the stick in a turn but also open your throttle or as seasoned glider pilots will know, put the nose down. (This is also why a lot of tip-stalls and crashes occur on down wind turns or final turns in a dead-stick approach following engine failure. You won’t so often find glider pilots suffering the same fate… they’re always dead-stick!) If you need more lift you will suffer more drag – remember you have an unavoidable lift to drag ratio. This is the reason your model is “gently slowing down and sinking,” not because of the dihedral. You need 41% extra lift and lift is a function of the square of the plane’s speed so to get your 41% extra lift you will need to increase your speed by the square root of 1.414 ie 1.189. So 19% extra speed and you will get round the turn without sinking. I think I got that right. Edited By Airhead on 07/10/2018 20:10:36

“It is amazing just how little power you can fly on isn't it?” says B.E.B. Just as an aside, how much tension do you think is in a full size glider aerotow cable? Big, powerful tug yanking a heavy sailplane along – it’s going to be loads isn’t it? Well, let’s imagine a tug pulling a modern sailplane along. For the moment, just along, not up. We’ll pick an ASG 29 as our modern, efficient sailplane and, as an ASG has an empty weight of 280kg and a max of 600kg, for OUR glider, let’s pick a nice round figure of 500kg with pilot and a bit of water ballast. Now the ASG has a max glide ratio of 50 to 1 so let’s settle on that too. As the enlightened will know, the glide ratio is equal to the lift to drag ratio so our ASG also has a lift to drag ratio of 50:1. How much lift do we need to keep a 500kg plane in the air? Yep, you guessed it, 500kg! Not rocket salad is it? So if we need 500kg of lift and the lift to drag ratio is 50:1 then the drag will be… Correct again! 500kg divided by 50… a mere 10kg, and all that towrope is doing is matching that drag figure. Not much of a pull to keep a dirty great, half tonne glider in the air is it? (As a caveat, I must say this is for a constant velocity, constant height situation. Add acceleration and/or height gain into the equation and you’re looking at completely different calculations.) So how little power a Junior 60 will need to fly on, just to stay up, almost pales into nothingness. It’s all ultimately about its lift to drag ratio. It will need little lift as it weighs so little. All the power put in (again at a constant velocity and height) is doing is overcoming the J60’s drag. The thrust of the motor is merely taking the place of the glider’s towing cable. Reduce the drag with streamlining and you’ll reduce, pro rata, the power needed. So if you halved the drag, you’d halve the power requirement and so on. Reduce the drag to zero and you wouldn’t need power at all, no matter what the weight of your plane/model it would stay up for ever! You could take the undercarriage off the J60, hand launch and check the figures again – I expect you’ll find quite a reduction in power consumption. Oh well, I think it’s interesting!

Hi Andy, How about a plan from Outerzone – I suggest the Morris Mustang (have a look at https://outerzone.co.uk/plan_details.asp?ID=9811) or similar. This fits your requirements – it’s 46” span, has a goodly amount of open structure, quick to build, aerobatic and, I know you are a bit of a scale man so I’m sure you’d like the fact that it’s vaguely scaleish. Plus, always a good one, it’d be cheap to make! It also takes a .40 or thereabouts, probably the easiest/cheapest size engine to pick up if you haven’t got one to hand. (Usually plenty on eBay) If a Mustang doesn’t fit the bill, have a search through the plans there – there’s almost certain to be something similar that does appeal, such as maybe a Gee-Whiz-Bee (GeeBee R1 – ish) https://outerzone.co.uk/plan_details.asp?ID=9429 (BTW, I don’t suppose you’ll remember me (Phil) but you might remember my dog, May, the little old brindle EBT in the back of my car from a few years ago at the free-flight nats. I remember you or Mrs S. took some photos of her. She’s sadly no longer with us – you’ll have to put up with just me.)

Biggles' elder bro said, " ...every time I turned towards me the model effectively disappeared - basically it's a small white model against a light grey sky no contrast in a head on orientation! I'd let it fall off away from the wind so it turned and could see it, but of course ever time I did that I'd lose another 50 yards downwind." I too have had this problem, flying a scaleish (thus white!) glider that had a superb glide angle but no spoilers or brakes, so the landing approach had to be started from somewhere around the middle of the next county. I had a fair walk and picked up an undamaged model but was instructed what to do next time by a ex F3J competitor who had done this many times... "Fly it blind!" I was told,"If you can't see it, it's coming towards you! - Eventually you WILL see it." Hmmm... logical, yes, and easy to say, but it's difficult to stand there, grit your teeth and be content not seeing your model.

My approach is a ballpark calc based on power to weight. If you double the size of a plane, it's weight is 8 times the original (roughly, ballpark figures remember) as it's twice as wide, twice as long & twice as high. 2x2x2=8 so you want an engine with 8 times the power. Well, it works the other way too... if you have an engine with, say, 50% more power you can enlarge a given plane by the cube root of 1.5 (150%) which is 1.14 so enlarge a plan by 14% (to 114%). In your case let's assume your Saito 100 is 100/80 the power of the 80 ie 1.25x. If you calculate the cube root of 1.25 you find it's 1.077 so you can enlarge the Stuka by about 8%. Just an estimate - you may find the original is well powered and the enlargement would comfortably fly on the 80 anyway. It also depends on how you like to fly; wanna rip up the sky? You'll need more power than someone who wants to cruise around with an occasional touch and go. Adjustments can be required depending upon the type of engines to be fitted - you already compensated for the change from 2-stroke to 4 but similarly, an old Merco will not give the same output as a same displacement piped Rossi...!

Thanks all who have replied but it seems we're not getting anywhere yet, The ESC does indeed look just like the DYS onebut the programming is different so it's a dead end there I'm afraid. I have rooted through about twenty and counting PDFs of instruction manuals for various ESCs to no avail. I think the defining difference that someone may recognise is the fact that it beeps once, twice, thrice, etc up to SIXTEEN times(!) when energised with the throttle advanced. No long beeps, no music, just lots of short beeps. If that is familiar, I may have the same brand as you...

Good thinking Barry - it WOULD be easier... (but not cheaper!) The ESC, being in a glider, is primarily for launch and, not being BEC equipped, it isn't needed for radio operation so I feel it'd be fine to use. (I fly pure gliders mainly so I'm kinda used to landing deadstick!) Good thought about the safety aspects though, both for the aircraft and everything in the vicinity too. All I need is someone to recognise it and say "Oh, I've got one like that, it's a XYZ, you can download instructions from..." and I'll be away. If it responds correctly to the instructions then that in itself will be a double check but, as I say, it's not a critical component in it's current use.

Thanks Dave but I have no problem with getting it to run and throttle from nothing to full chat - I need to engage the brake and I'm not sure that ALL ESCs will work out what battery is connected and I would like to tell it what's what in that respect, especially as I have a selection of them including NiCads and NiMHs that I would use. And I'm lucky enough not to suffer the slings and arrows of programming a Fruity-Bar radio (been there, done that - never going back!) - Multiplex 4000 for me! If I can discover the make of ESC, I can search for operating instructions and, with luck, set up the details.