Head in the clouds

Rivets should always be set into holes that are 'a bit' larger than the rivet diameter. Otherwise the rivet doesn't have the opportunity to expand and properly conform to the shape of the holes in the materials which may, or may not, be perfectly matched, but the rivet can take care of that. A slight mismatch actually make the rivet grip a little better and prevents it wanting to rotate with vibration. Not that you should aim to have a mismatch of course ... More importantly the rivet needs to deform into the larger hole because as it does so the rivet work hardens, making it more durable in service.

Might be old but that only poses the question of how long this has been going on. Here's another of several on Youtube, posted in 2007 ... and the poster introduces it with - "Plane trip in australia, the town of 1770. The pilot, Bruce, decided to show us some acrobatics and plummets us into free fall without warning. Leeroys face is priceless, he hates rollercoasters." You can see the pilot's face quite well in the opening part of the video, looks remarkably like a ten years younger Bruce Rhoades, the owner of the air service, based on the picture of him in the news reports earlier in this thread. Same kind of 'acrobatics' too.

Yes, I found half a dozen similar videos and it appears to me that there's a rather questionable 'culture' in that operation. Most of the videos feature Bruce as the pilot, and if the boss operates in a particular way I think it'd be likely to have a rub-off effect on other pilots in the line. Things I noted from the videos that appear to flout the CASRs for a Commercial joyflighting operation might be - Pax not under instruction but permitted and encouraged to manipulate the controls Aerobatics in utility category aircraft that are probably not rated for it Rear seat passengers carried during aerobatic flight - this could move the CG aft of the most aft position permitted during aerobatic flight and/or could make the AUW over the max weight permitted for aerobatic flight (if the aircraft was permitted to perform aerobatics in the first place) Passengers told to remove their seatbelts then deliberate negative G operations conducted Deliberate aerobatic flight with unsecured items in the cabin Extended periods of low-level flight which was not during take-off or landings Though it might be the kind of madcap antics that backpackers actively seek, as you said gibby, it doesn't paint a great picture. I can think of a few shoes I probably wouldn't want to be in as CASA and ATSB delve deeper into this investigation.

Yes ... and that was just watching it!

Now you're onto something. I particularly like the strength in the cabin sides - they shouldn't fold up and crush the occupants like the early unmodified RV6s seemed to. Just one small thing - the lightening holes in the rudder-post don't reduce the weight very much at all but they do allow mud wasps to build their heavy nests inside, which also have the potential to interfere with controls when they rattle loose. Similar with the HS spar when you get to that.

Revisiting this thread, it surely must be eligible for an award for having discussed more 'off-topics' than most ... excellent, there should be more of it! Meantime back to the original post - I had another visitor last night, and this time the wings brought their body with them, so now I know what the rest of the little criitter looks like. Does that mean that this is what nature's 'perfect body' looks like?

I'll put that on the bucket list. I spent a short while mustering on Nappa Merrie about 25 years ago, there's never a dull moment down that way ...

I'm not surprised about that, hail can be very destructive, I've seen an aluminium airframe that was hailed on with holes clean through the metal skins - and it didn't fly through the hail, it was tied down, also in SE Qld. A couple of years ago highrise buildings in Brisbane had their supposedly bullet-proof plate glass windows smashed by hail, and that was from hail striking it at quite an acute angle. Hail arrives at a lot faster pace than a cricket ball but as far as the fabric damage is concerned it's also a lot sharper. My comment about the fabric's ability to withstand a cricket ball was just an estimate, perhaps not a Mitchell Starc though? Anyway I'll be covering my project in the next few months, maybe it's time to conduct another experiment ...

Welcome OBA, and Happy Christmas!

Great stuff Mark. Looking forward to watching the rebuild.

Heehee, I don't think FH dislikes the look of radials, I think he dislikes the look of those particular ones. Methinks Nev is a triple row Wasp sorta fella.

Don't tell the Czech Republic that - with their lovely 3, 5 and 7 cylinder Scarlett radials from Vernermotor ... 137hp at 2200rpm, 83kg, no reduction gearing required, magnesium crankcase ... And their 69kg 83hp 5cyl version might suit the Jabby well perhaps?

Hey OME, Really sorry to hear all is not well with Ma Emu. Do hope she's up and running again very soon. I'm sure she'd have loved the poster, very caring of you to put that together. I'm sure that lots of Recflying forumites share in sending best wishes and thoughts for you at this time - do pass them on to Ma, hoping it gives her a little festive season cheer up :-)

Yes ... sometimes perhaps. Sure, variation and different input can be beneficial at times, and particularly if you're stuck with an instructor you don't get along with, but generally it's much like any schooling, for best results you need to have a developed relationship with the tutor or learning will be more fractured. In my experience best results came when students found an instructor they worked well with and did the majority of their training with them, with occasional flights with the CFI or another instructor. There's no 'one size fits all' solution though, of course.

Um ... I don't have any agenda here at all, except, as I said, that I'll comment about matters "which if not corrected could possibly have fatal consequences". Why would I have a harmful agenda as your post above seems to suggest? If you recall, about three years ago I spent about an hour just about every day, for months, writing you long emails to answer your questions, which gave you the majority of your initial knowledge of aeronautics. I then spent a few days helping you by inspecting and writing a review of an aircraft structure that you intended to buy and manufacture. You also used my 'credentials', based on my fairly long history of designing and building sport aircraft to give your 'company' added credibility when it was seeking investment. I never have claimed to have any engineering qualification, however at the time you chose to present my previous experience as sufficient competence. I have always sincerely hoped you might make a go of it, this sport could certainly do with a much less expensive kit and engine. All I've ever done is offer you the benefit of the experience I've gained through previously making most of the same mistakes you're making now. There's little point asking you for information about specifics, because you always say the same thing, "there'll be an announcement soon", but 'soon' rarely seems to eventuate. If you re-read my post about your wing carry-through (BTW, there were three of my posts on that page, not one), it was very considered and provided you with full justification for my concerns, complete with simple calcs based on what appeared evident. By showing the calcs process it allowed you to insert your own data if you wished and come out with the 'real numbers' rather than my assessed ones, but you didn't do it. At least, if you did, you didn't post the real sizing and result - and in post #254, you declined to say what the actual sizing was, so what's the point in asking? If I was so wrong I wonder why you promptly abandoned that carry-through and substituted a different one. I know you said the first was just a 'test piece', or words to that effect, but if that was really the case why bother to go to all the expense of laser-cutting hundreds of lightening holes in it? BTW, you say you have these aeronautical engineers working/consulting on your project - have you asked them what they think about the welded aly truss? I just called and asked one of Australia's most experienced aero-engineers who has many designs under his belt and his words were, "Welded? Steel, yes, not aluminium, not in the primary structure". He never was a man of many words ... I don't know why you decided to mouth off at me like that, I didn't suggest the welded concept, and it's not my fault if you think up and set your heart on ideas that might not be best practice, so don't shoot the messenger, as they say. Anyway, despite your unwarranted venom, I still wish you well and I'm sure if you stick to more conventional aircraft structural practices it'll meet less buyer resistance than if you include a bunch of 'unknowns'.

Don't worry about how long it takes to reach solo, it's quite irrelevant. When I was instructing it became evident that many of those that went solo quickly tended to stagnate for a while afterwards, whereas those who took longer at the beginning often ended up the best pilots because their learning was constant and they absorbed more, and forgot less. Just enjoy the journey.

I'm not sure you're right about that. Previously you (like Morgan and others) had your longerons attached to verticals and diagonals with riveted gussets. In terms of the truss your longerons are your top and bottom chords, and your verticals and diagonals are your web members. By necessity your web members are individual but your chords MUST be continuous, or spliced with a moment connection, or else it isn't a truss. When they were riveted your chords were continuous but by adding welds every so often along your longerons/chords, you've effectively broken them up into pieces - or will have once the fatigue sets in - and the additional riveted gusset does not constitute much of a splice. Once the chords start to crack up you won't have a truss, or, effectively, any longerons. So if you're building something where your load paths are as distributed as you claim, why bother to have longerons and/or a truss in the first place? If widely distributed load paths are your design intent why not build a proper monocoque like the RVs? Cheaper, lighter ... and compared to this case, far less prone to fatigue failure. I think they are relevant. I recall your telling me that you had no intention of flying in small planes and that your sole interest in this field was to produce engines and airframe kits. By benefiting from China's low cost materials and labour, they would be cheaply priced so you would sell lots of them for a handsome profit. There's nothing wrong with profit of course, but the kits people sell don't have to pass any form of testing in regard of whether they will assemble into a safe flyable aircraft. The onus for safety and airworthiness and structural integrity falls on the customer, not the kit producer, as you're aware, and if you're not planning on flying it yourself there might not be quite the same incentive to make sure it's perfectly sound. Nonetheless, for good business reasons as well as the ethical ones, I think it behoves anyone producing a kit to ensure they're employing best practices rather than introducing ones that are known for being unreliable. A while back you said you didn't have any formal engineering qualification. There's nothing wrong with that either, many people with knowledge gained from the internet forums and discussion with their peers have designed and built quite adequate aircraft, but without their having the personal ability to fully analyze every aspect of the loads, stresses and metallurgies involved, we're generally well advised to keep our design parameters within established boundaries, in effect closely emulating structures, member sizing and methods that have been previously formally engineered and proven on similar-sized and loaded designs. That can be quite successfully achieved without 'copying' the design, and also without needing to end up with something that looks significantly similar. If you produce a kit that assembles into something with poor flying characteristics, or which is not structurally sound, those defects will quickly become evident and you won't sell many more kits, so the problem would be self-resolving. However designs with in-built fatigue issues are far more sinister because the failures won't start to show up for quite a while, several years perhaps, by which time there may be many others of them flying and in advanced stages of assembly. People who've invested considerable time and money in buying and assembling their 'baby' don't tend to be willing to trash them without a lot of resistance, consequently they're a ticking time bomb and people die as a result. Some might consider one model of the 601 to be a good example of that, when they started to gain an unenviable reputation for inexplicably shedding wings, apparently some unscrupulous people quickly sold them to unsuspecting buyers who weren't aware of the problem. I imagine someone else will conduct your test flying and every one of your customers will be doing that also. 'Test pilots', and also the vast majority of the people who assemble a kit, rarely have any significant or relevant engineering knowledge themselves, so when they fly the creation they've assembled they're very literally trusting their lives to the person who designed the thing - that person presumably having done so with suitable and relevant knowledge, or where that might be lacking, having sought and heeded appropriate advice. I've largely refrained from commenting on your build because on the two or three occasions where I did your response seemed to be less than appreciative. And your reaction to the considered input provided by several here who are very knowledgeable and experienced builders has been quite dismissive, to the extent where it's noticeable that most have not bothered to contribute any further. Nonetheless, if for no other reason than duty of care, I do feel it necessary to point out things which are clearly wrong, and have been shown by others' previous experience to be so, and which if not corrected could possibly have fatal consequences.

Yes ... and the heat affected zone of the 6061 is then no longer T6, it's fully annealed to T0. Depending on the radius of curvature and the wall thickness of the tubing, another thing you may find is that if the longerons are curved when they're welded they'll relax due to the heat from the welding, and adopt a series of facets instead of a smooth curve. It would probably be inconsistent too, some operators would weld hotter than others so the degree of relaxing of the curvature would vary. Welding works OK for marine and transport, but welding of aluminium primary structure really isn't a very good idea for aircraft because the members are so much thinner. That's why welded aircraft structures are usually chromoly tubing. I seem to recall that Grumman tried it with aly way back, I think it might have been for a Goose or Mallard derivative, because it would have made sense to weld flying boats rather than drill and rivet them, but IIRC they had so many fatigue problems in the testing phase that they dropped the idea.

Well, if you're really serious about it, there's never been an easier time to learn. With the benefit of welding equipment manufacturers posting every tip and trick on YouTube videos these days, you can learn all the theory and basic knowledge from the comfort of an armchair and be fully informed before making any decision about what equipment to buy. To make a start I'd highly recommend the series of 'welding tips and tricks', one of which I posted above, and also the posts from Miller, who make, arguably, the finest welding machines of all. I'm reckoned to be at least passable in my welding and I learned the basics from books and trade tutors but the really refined methods from those YouTube videos. I'd love to have a Miller TIG machine but I've shown that even with my ultra cheap ($800 delivered) Chinese multifunction it's quite possible to make very acceptable aircraft quality welds on very thin material ... the thinner it is, the more difficult it is, so you don't have to start out with the most expensive gear.

It's quite possibly robotic welding but I've seen work just as good done by hand. It's TIG welding of course, and when doing those kinds of pipe joints manually you use a method called 'walking the cup' where the cup is held in contact with the work and 'walked' from side to side with a deft twist of the wrist. Keeping the cup supported on the work-piece takes all the shakes out of the hand and makes it much easier to keep a steady rate of progress, concentrating mainly on dipping the filler precisely. You can only do it on certain joint types where you have two surfaces to rest the cup on. Here's a Youtube vid that shows the process - and how to do as good a job with a 'TIG finger' if/when you don't have a clear surface to work against -

I can imagine winding the car jack up and down a hundred times or so would have been a bit wearing ... I guess it's a bit frustratingly late to mention it for your current build, but it doesn't actually take much force to press the flange around the lightening hole, so next time you don't really need a jack or a powerful shop press. On mine I use forming dies that are virtually identical to your friend's, and I just bump them together using the quill of the drill press. It's pretty much effortless and each one takes about two seconds - Terrific craftsmanship once again Marty, and another great set of scratch build photos, thanks for posting

If you fellas up there in the Top End keep having so much fun, you're going to end up having surgery in hospital ... to have your huge grins removed

Very impressive management of the situation. Many experienced pilots would be hard pressed to perform so well. After touchdown his control inputs continued to be spot on to hold the plane level for as long as possible - the opposite rudder and aileron is clearly visible in the video. What I found particularly notable was that he was sufficiently on top of the situation to be able to shut the engine down while the plane was still in the groundloop, the airscrew stopped before the plane did. Well done young man!

Jeez ... I've heard faster conversation out on the cattle stations, it's taken you six years to answer his question rotor. I bet his hangar fees have gone up since then too!

Back in the Drifter days I did a lot of beach flying. I had a custom made fibreglass box under my knees which I carried tools and 'allsorts' in. Among those items were a quantity of fluoro-coloured golf balls. I'd select an area of beach that looked firm then fly over it at about fifty feet and drop golf balls about every fifty metres or so. If they bounced it was a safe landing area and if they went 'splat' it only cost me a golf ball or two, much cheaper than an inverted plane ... Mind you - folk should keep in mind it's not legal to drop anything from a plane without a CASA dispensation, so I guess that safety precaution is actually off limits. What was surprising at first, was the frequency with which a largely firm area had small very soft patches in it. After a while I could usually spot them because they were just slightly wetter than the surrounding sand. The reason they were soft was water coming to the surface. Some of them were quite active quicksands too. Flying low towards the sun helps with spotting them because the sunlight reflects more off the wetter areas. I had golf buggy wheels and tyres on the Drifter, and ran them at about 8psi when flying off sand. About Wyndham and Derby - neither of them have any beach at all but we did used to fly off the mud flats, you can land on the light-coloured stuff where there are vehicle tyre tracks but stay well away from the dark stuff and anything close to it or it's gooey mud or a thin layer of drying mud covering ooze beneath. Wouldn't be any fun to break through it. Derby has the world's biggest tides, 14m at Springs on king tides twice a year, and over 11m the rest of the time. Derby's airport is Curtin RAAF airbase, about 15 miles inland. Broome has huge tides too and Cable Beach is a perfect place to land provided there hasn't been a major storm for a while. If there has been it gets gulleys/washouts through it which can be hard to see but would rip the gear off if you hit one. Cable Beach is an optional dress beach and is also a gazetted road. It's about 10-12 Nm long and used to be quite easy to get CASA permission to land on it provided you put in a formal request at least 28 days in advance and detail your plans for safety fences/warnings, SMS and all that. For a few years I ran helicopters and plane flights off there during Shinju, the Festival of the Pearl, and it worked without a hitch because the place is so large that there's plenty of room for everyone. Speaking of the largeness of it, beware the speed of the tides. They're up to 13m there and the inter-tidal zone is very flat which means the tide goes out a mile or more but because the gradient is so low it comes back in 'faster than a horse can gallop', as some of our early explorers found out to their cost. And on Spring tides it comes in right up to the dune vegetation leaving only traces of soft powdery sand which you can't even drive a 4WD on, so you need to make your flight in on the falling tide, preferably at about half tide. There are plenty of large and beautiful firm beaches on the West Coast which are remote, and although it's not legal to land on them anywhere without CASA permission, because all WA beaches are Crown Land, if you do your homework on Google Earth and elsewhere, you'd be very unfortunate to be sprung but you wouldn't want to get stuck because it'd probably cost you your plane and a hefty fine. Some of the coastal cattle stations have blanket approvals for beach landings, so it might be worth contacting some of them, with the right approach they're usually very helpful.