pylon500

G'Day Doug, Just looked at you latest renderings and where you have understood me, you have depicted well. Now for the bits I obviously didn't describe well enough; In the first picture, the 2' overlap is correct (this gives you a 22' span), the depiction of the laminated angles is incorrect in two ways, the longest angle (light green) should be around two thirds of the length of the C spar (8'), the second angle (dark green) should be around one third the length (4~5'), and the smallest angle (blue/grey) should probably be around one quarter of the spar length (3'). In both the first and second picture you should depict two sets of angle doublers. The ones shown should be sitting in the bottom of the channel, and a second set should be up inside the top of the channel. In hindsight (and looking at your graphics) I can see it would be easier to rivet these angles to the C channel spar through the top and bottom flanges (caps) to avoid confusion when riveting the wrapped leading edge flanges onto the vertical (web) part of the spar,as depicted in picture 4. You also need to do these drawings for the other wing, showing the C spar the other way so they overlap. This may show up some other possible problems....... The folded trailing edge is pretty much as I described, the details would be in the diameter of the rib tubes to dictate the width of the trailing edge. The diameter of the rib tubes then needs to be decided via the compromise of how much unsupported rib can be carried, versus the amount of bracing required, versus the weight penalty taken by using bigger tubes? Smaller diameter tubes will need more bracing (ie 1/4"Ø) whereas larger diameter (3/8"Ø)would need less, but would be more bulky and heavier? If building a constant chord wing, then the ribs are all the same, why not knock them up out of sheet alloy as per normal procedure? Have a look at my 'mass produced' ribs in my Stearman project; https://picasaweb.google.com/113292981019876413104/MurphyRenegadeStearmanProject They are not really that hard to do. Back to the spar web, yes, use lightening holes, flanged as depicted. They could be a little closer together than drawn above (what pitch did you use?) These would run from the tip to about the one third from the centre, try to avoid having a hole line up with the end of a doubler angle. OK, the wing joining bit... Forget about the 1" square tubes, I've had a netter idea.. You have the two spars overlapping back to back for about 2' in the middle, you need to figure out how wide the fuselage is at this point and determine what the wing is going to attach to on the fuse. You will probably need to double up the vertical tubes behind the seat to four, so you end up with tubes in front of, and behind the two spars. These tubes need to go up to about the horizontal centre line of the spars. This is where the spars and the fuse all join, via two bolts, one through each set of vertical fuse tubes and the back to back spars between them. These bolts should NOT go through the spar web doubler angles, they should go through the web area at probably about one third of the spar depth, from the bottom. Because this is just two pieces of spar web (trust me 0.032" spar webs should be plenty) it needs to be reinforced to give a bearing surface for the bolts, heres how... Between the spar angles, we need to build up some vertical plates about 2" wide (three lots of the same thickness as the angles, 0.032"x3) PLUS, two more plates that are long enough to fit in between the caps. Riveted with two rows of rivets, and room for the actual wing joining bolt. This got really hard to explain, so I've had to spend an hour or so knocking up this drawing; The next thing I notice is that we are going to need a rear spar, but as it's getting late, I'll come back to that later... Arthur.

This is starting to look more 'doable' as we go.. With a small enough span, simple cantilever spars should work. The aluminium tubes for ribs will work, although there is a bit of excess material there, but at this scale, probably OK. You will need to do a bit of bracing within to hold their shape. For your leading edge I would just use thin alloy, 0.016" 6061-T6 should do, but do away with the wood packers and just fold a back lip down and rivet to the spar. This will give a sort of 'D' tube, albeit with gaps at the ribs. The folded spar can stay reasonably thin, say about 0.032", just add laminations of angles from the centre outwards, probably more 0.032" about 1"x1", the first going two thirds the length, the second going one third, and maybe one just going a quarter of the spar length. All riveted to the web section. The back to back idea is used a lot, but remember, the joining of the two spars doesn't need to be done through the caps. A couple of good verticals, say 1" square tube with at least 1/8"walls bolted to the caps (inside the 'C' at the join point) and having just one bolt, say 5/16th 'Ø, or 3/8th if your nervous, through the middle of the square tubes. Wish I was better, and quicker, with a graphics package:smash pc: Your trailing edge need only be 0.016", probably around 2" wide with a small lip top and bottom. I like the tailwheel arrangement drawings but think you may need to brace the square shape joining the four trailing edges. The shape is also starting to look a little familiar, have a look at; And check the articles here; http://en.wikipedia.org/wiki/PDQ_Aircraft_Products_PDQ-2 And, http://forums.bmaa.org/default.aspx?f=17&m=93273 Arthur.

Re the Peugeot ad;

Just finished going through my Latest edition and yes, I was a little disappointed in the photo content. As mentioned, the cover was just a patch of blue with a GA plane doing things we are not allowed to do (how does the newstand public perceive that?) Then there is the 'centrefold(?)', a 60 year old GA plane with a lot of empty blue behind it? I guess the Antique Aircraft Association is going to give us equal space and put a Jabiru in their next centrefold ! Personally, I'm not a 'people' person, and tend to like looking at pictures of aeroplanes, but I guess it's good to show that there are people involved with flying, as such, I liked the shot of Ben McGuinness and his Waiex heading Arthur Marcel's article. This showed him and his aeroplane, not just the tip of his prop. I wont complain about the advertising as it pays for the magazine, and tends to show a wider variety of aircraft than the articles. I was a bit confused however by the small image of the silly convertible flying machine amongst the letters to the editor, try as I might, could find no letters, articles or comments regarding it? Just a page filler I guess? All this aside, I suppose we (I) really can't complain if we (I) haven't put in any articles ourselves....

While it is amazing just what will fly, the short answer here (as defined by what has been made so far) is NO, it will not fly, which is good as there is less chance of more aviation related sensationalism being hyped by the media. Observations; If the wing structure relies solely on the steel tubes in the wings, they will fold off before liftoff. If the wings are fibreglassed, as the tail appears to be, the total weight will be high enough that by the time the aircraft reaches liftoff speed (if attainable), the wings will fold of again. If being in India, there's a good possibility the engine is out of a Morris Minor, ie, will not reach liftoff. It is a pity to see so much effort go into creations with no real chance of succeeding, especially in an economic environment as theirs. Arthur.

I cant find one of my good drawings to show, but I will try to explain; This is a project I have on hold, that was to use a R503 mounted upright with the gearbox also upright, and having cheek cowls like a flat motor. On one side is the carbi's and filter(s), on the other side is the exhaust. These items are more or less in line with the prop shaft so the effect is quite neat. More of this project at; https://plus.google.com/photos/113292981019876413104/albums/5194978509871592929?banner=pwa I'll get back to it one day. Arthur.

Not quite sure I understand if this is to be a full VW, or a 1/2VW? Or is this the anticipated total cost? If it's a full 4cyl, with start and dual mags, it will be very heavy and as ugly as that black and yellow thing (sorry to the owner, but look at the front of that thing ) Next point, if it's to be a 1/2VW, you will be lucky to get 25hp out of it, really! Dave King and Brian Gabriel before him could both see the only way to go is a 2 stroke. You can probably get a reco'ed 503 cheaper than the VW(which will also be reco'ed), it will be lighter and it will put out 50+hp. It wouldn't take a lot of work to clean up the exhaust setup. The weight saving of a 503 would offset some larger tanks in the centre section to avoid CofG changes. I've recently been trying to test fly a machine designed for a 503, that was fitted with a Revmaster, it's not looking good. The motor feels like it's putting out about 40hp, and the aircraft came out a bit heavy. The net result is minimal performance. Just found another two stroke Hummel here in Oz; http://www.lmacrc.com/Photos/2006/Home Built.htm I think some large side cheeks could hide the exhaust on one side, and the carbi's on the other side...... Dont get me wrong, the half VW Hummels are out there and working, BUT, the good ones have no electrics, are hand start, and take off from 1000 ft of concrete. I rest my case; Arthur.

Can't say I've actually looked up what this is (I'll get around to it), but just from a basic aerodynamic layout,it looks OK. Some points though, yes I agree with the others re the billy cart steering. I built a trike many years ago, but as a normal aircraft pilot, the idea of billy cart steering didn't appeal, so I made a pedal arrangement that pulled from the bottom of the pedal hence turning the nose-wheel fork in the right direction. As a bonus I mounted an inverted T shaped item just in front and above the tire, held off the tire by a large spring. Thus if I pressed one pedal, it pulled the fork to steer, if I pressed both pedals (against the spring) the T bar pulled down onto the tire, giving me brakes! Now, other points; Had you thought of a tail dragger? Symmetrical section, pro's and con's, no pitching moment (good); Flies at higher angle of attack (how much rotation clearance do you have?); Thicker (how thick do you need?) With the area your looking at, I would stick with a semi lifting section, look at a Foxbat section, has good stall habits, low pitching moment and a bit of thickness. Power plant setup, a long toothed belt like that will have a lot of 'whip' which needs to be controlled, and if running from a two stroke, will need reduction, so how about an upright motor behind you on the bottom using a toothed (or poly V) up to the wing with twin sprockets on the same shaft running chains in tubes to the prop shafts? Sounds ancient, but remember chains have less losses than rubber belts, and you've absorbed the impulses back at the reduction point. Looking at your 'cutaway' of the tail, why bend or break the main tail spar, and then only support upwards with cables? Remember, there is a download on a tail inflight and the joining brackets to hold angled tubes would be wasteful in weight terms. Maybe a tail half up the fin with cables top and bottom Still don't see the point in the angled tip fins? Would be better to hang the ailerons on the lower wing, less complicated to connect, and just use end plates for tips. Is the prop spacing to get them in clean air, or just look good? I know you don't intend to get asymmetric thrust, but if put as close to centre as possible, is lighter and more controllable if you do lose one. You also have not shown any drag (thrust) bracing within the wing to hold the props Any intention to wire brace the wings, or just use big tubes? The end fins wouldn't do anything to support the wings so you need a strut or wires (or big tubes, I'm talking around 4"Ø here) Do you really need that square tube for the nose? Just continue the twin tubes all the way, have a look at the Mitchell P-38. Please don't think I'm trying to shoot you down. I think your onto something, (although I designed something similar many years ago, look in top right here; https://plus.google.com/photos/113292981019876413104/albums/5212775815502683841/5213148201835122130?banner=pwa). I'm in a position that once I've seen something, then I can see where improvements could be made. Arthur.

OK, the concept shows promise. Tend to agree with others that the props are not going to be in a comfortable position. Could they be pushers behind the top trailing edge? Point 2, a V tail will have a lot of trouble trying to handle asymmetric thrust. Also at that short a wingspan, the V tail will give you a lot of adverse ROLL with rudder application, an inverted V tail can solve this. Personally, I would go with a flat tail with twin fins, or a simple T tail. Does the end plate joining the wingtips really serve any purpose? Short wings like that could be cantilever, and simple tip plates will give you apparent extended span. Would be a lot less complex with a single pusher, but I see we're doing this just to be different..... If we want LITTLE, have a look at this; This was hard to find, but have a look here;http://chuckisawesome.org/?p=996 Arthur.

As a previous glider pilot, I am also not a fan of Frieze ailerons for the drag reason, and also not a great fan of flaperons because of the adverse yaw problem ( he says while spouting praise for the Foxbat ?!?!) so we are on the same page.

This mainly applies to faster aircraft when flying at low speeds, like take off and landing. While twist (washout) can have some structural problems at higher speeds, this doesn't really apply to us, so we are better off just having a bit of twist. It's also lighter than flaps. No, not really, the gazelle system is more akin to what Junkers was using back in the 30's. The AN-2 uses a sort of Frieze/Fowler type flap and aileron, much like the Foxbat uses today. For the picky, the more 'remote' the hinge point is, the more Fowler it is. The real difference is more to do with the underside of the trailing edge of the wing in front of the surface, if it's square like a Cub or Spitfire, it's a Frieze. If the underside is rounded to allow smooth airflow up over the surface, like the flap area on a Cessna or the Foxbat (regardless of hinge point), then it's a Fowler. (That's my view anyway..) Arthur.

In lay terms, if the wing stalls in the middle first, then the aircraft is being supported by it's wingtips, which would be stable. If the wingtips stalled first, chances are one would stall before the other, making that wing drop and roll you over on your back. Not what you want close to the ground! Various means are used to ensure the centre of the wing stalls before the tips; 1. Washout built into the wing, which is twist along the wing giving the tips less angle of attack than the centre. 2. Change of wing section type along the wing, where the tip section is given a higher lift coefficient than the centre, which means the centre looses lift before the tips. 3. Aerodynamic devices added to the wing to either maintain lift to a lower speed towards the tips (cuffs, fences, vortex generators), or other devices to actually destroy lift near the centre at low speeds (stall strips). 4. The use of flaps will have the same effect by changing the angle of attack between the flapped area, and the non flapped area. With all this in mind remember, if you are close to the stall and/or at a high angle of attack, use of the ailerons will usually cancel the effectiveness of all these devices, and you will end up on your back again!! How to create and use ailerons or flapperons at low speed is another lesson........ Arthur.

Interesting to see that they are allowed to sleep for 40 minutes.....? "This is your Captain snoring, ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ" Yeah, I know it was the FO..

G'Day Ross, You are right in that there was a weld repair at the point the axle broke. Why it was re-welded is unknown, nothing in the logs, but it had been welded on both sides, see photo; This is the other side and was only found after the accident. The reason I comment is that about 20 years ago, we had the exact same failure occur on our club GR582. Examination of the axle showed that it had been cracked for some time, we suspected since new, but being on top of the axle, it was being held closed by the weight of the aircraft. The crack propagated over the years until a slightly heavy landing caused it to fail (same as mine). That GR582 was serial #5, mine is #83 and still had the thin wall axle and no solid plug inside? Some axles look solid, but actually have blanks welded on the ends (like mine). Something to watch for...... Arthur.

Another point worth inspecting is the base of the wheel axles. Remove the wheels and look VERY closely at the top of the axle between the bearing collar and the welds to the legs. Dont get me wrong, these are great planes, but this is something to watch for... Arthur.

Looks like we're trolling at the same time, just looked at the picture and thought "looks like a Renagade", did a quick search and got, http://www.regosearch.com/aircraft/au/LFZ

Put this 'sherlock holmes caricature' into Google, then click on image....

OK, just looked at photo's. You're on the right track, but the critical part in hinges is the hinge line, you need to know exactly where it is to get it right. You need enough material to to create patterns of ALL the hinge pieces, not just one and reproduce it, (Titan may have done this with a jig, but you always get movement). As for the rolled hinge being a bit open, before separating, lay the hinge on top of a vice with the roll in the gap, and gently close the hinge. 1.Number all your pieces, as you have done, then separate all the hinges. 2.Cut up your extruded stock into the sizes required and NUMBER. 3.Using some form of clamp (duckbill grips, G clamps, even a vice), clamp a piece of hinge (new or old) onto your template material, can be plastic but a bit of alloy sheet is probably better (and cheaper), this is the guide hinge. 4.Take an old hinge and using the pivot pin rod, mesh the old with the piece that is clamped and fit pin. 5.Drill the holes of the old hinge into the pattern material, try using a drill with a fairly flat point, or it will walk around in the hole. 6.NUMBER the new hinge and put aside. 7.Unclamp the guide hinge and move to a new area and re-clamp as per step 3. 8.Repeat steps 3 to 7, remembering to NUMBER all new pieces. You will end up with a bit of pattern material that looks like swiss cheese, but each hinge piece will be a perfect copy of the original hinge. As for assembly, a good trick would be to rivet every piece of hinge in it's respective place with ONE rivet in the middle, then fit the hinge pins. Now hold the aileron up at 90°, and install the other rivets, this will keep the hinge line straight. See how you go.... Arthur.

Not sure that the OPEL, as a straight flying wing, has many similarities to a delta This would be a bit closer in concept; Read about it here; http://fraseraerotechnologycompany.com/Rohr_2-175_Fan_Jet.html. Arthur.

I first joined forums at an American Homebuilt site, and was already calling myself 'pylon500', so I created a little pylon racing gif with a program I had called 'Animation Maker'. A bit rough and pixelated, but does the job; Usually have the slogan 'Go Fast, Turn Left' under it. Arthur.

Inspiration from here maybe? Alexander Lippisch; Or maybe this french cartoon from the 80's, 'ROBOSTORY; Not knocking, looks like a lot of fun.

I think that quote is actually attributed to 'Woody' from Toy Story

Just tried to look at this thread, but got an odd redirect..?

I had a similar experience a few weeks back returning from Melbourne to Willytown on a Jetstar 320. Arrived off the coast of Willy at around 5,000 ft, and heard something mechanical being deployed, but couldn't see anything move, I was back around row 19. Figured it was the gear in an effort to slow down, which we did. We turned inland and crossed the coast at about 3,000 ft, north of Willy and began to pitch up to slow further when I realised that the Leading edge flaps had been deployed, but no main flaps? We then turned left again at about 2,000 ft and crossed overhead Willy, still decelerating and still no main flaps! By now I'm beginning to worry that maybe the boys up front were being distracted by the Hornet activity and had forgotten flaps (not supposed to happen in the computer flown Airbuses) and started to think 'What do you do if you think something is going wrong, and can't tell anyone?' At about 1,500 ft we turned mid down wind, feeling quite slow and nose high and finally a bit of flap started coming down, so I got out of the brace position and watched the rest of the landing. The gear actually started coming down on base and more flap was added on final and the landing was completed with a fairly sudden overpitch resulting in a good bounce, which was as suddenly dropped by the deployment of the lift dumpers. Probably a good thing I wasn't about to have my blood pressure checked at the time. In their defence, there was a fairly good (15~25 kts) wind blowing partly across the strip. I guess I've been watching too many of those aircrash investigation shows..........? Arthur.

My avatar is me sitting in the plug I used to make the moulds for my racer; project, https://picasaweb.google.com/113292981019876413104/BuildingTheLR2 A little photoshop has been used to add a canopy and U/C leg with wheel spat. Unfortunately this project has been shelved for a while as other projects, with the promise of being finished quicker (?) have taken precedence. This is the original photo. Arthur.