pylon500

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.

Have a look out around 'The Oaks' just West of Camden, and contact http://srfc.org.au/web/.

The Foxbat is rapidly becoming the training ultralight for those not wanting to struggle with the local plastic offering. It follows in the footsteps of the Gazelle, and the Lightwing before it, pity the A-22 is not available as a taildragger. And the visibility has to be seen to be believed.

A lot of those could go in the 'Guess the Plane' thread. I did recognise the prototype 'Rivets' racer near the end.

We want to see it on youtube!

Has anybody started a discussion somewhere else about this? It would appear to be an oversight from RAAus that has come out of the investigation so far. A list of which aircraft are actually under LSA would be interesting......

Not trying to brag (mainly because of a mistake) when I went to do my 5 hours, in a BLANIK, I forgot what time I took off. Took off with a digital watch at 11:50 and thinking to myself "OK, ten to twelve". After an afternoon of street running, NOT playing with clouds ( 'cause I wouldn't do that....) and running away from lightning strikes, (the day seriously overdeveloped) I got to thinking, "did I take off at 11:50, or ten to twelve, or was it twelve fifty?, crap!" So I just stayed there til I could see the sun going down and ended up landing after 6 hours, 15 minutes. I also got to 9300ft to get my Silver height as well, launch was about 3400ft. Just out of interest, the day before I did my silver distance in a Ka6, 105 klms, that took me 2 hours 25 minutes, I'm definately no competition pilot.

There's actually an entry in the maint. log describing other repairs nearby, and quoting the repairer, but nothing about the axle. As for work by certified welders, I'm a little unsure if certified (25-55-24) RAAus aircraft require this, or if it's just whether the final L2 is willing to accept the work and sign the log? As for the previous owner, I'm a little more unhappy at the manufacturer for not upgrading the material as the aircraft 'grew', and for not letting more people know about the problem. My original club had the same failure years ago on serial #5, I though that by #83 things would have improved..... Don't get me wrong, the Lightwing is a great plane and I can't wait to get it back in the air, but I will be doing a lot of close looking while I rebuild. Arthur.

OK, call me lazy, but could someone put up a link to where you can study these changes please?

As a side note, if you own a Lightwing, I would seriously consider taking the time to pull off the wheels, clean down the axle at the leg juncture and do a dye penetrant test. This failure has happened before. Arthur.

OK, here's a quick rundown, the report goes in tomorrow.. While training EFTO's a (no more than usual) heavy touchdown occurred. Instead of the expected bounce, there was a loud bang whereupon the aircraft pitched onto it's nose and a wingtip causing substantial damage. An undercarriage axle had snapped at a weld junction allowing the wheel to depart (found 150m's away!) and the end of the U/C leg to dig into the grass runway. Picture below shows the cracked end of the axle (still in the wheel), orientation would be top of the axle at about 11 o'clock. The dark grey area (4 to 7 o'clock) is all that was holding the axle together, the brown 'rusted' area is all crack. The shiny, lumpy area across the top, is a really bad weld attempt (probably MIG) where some-one has found a crack and tried to fill it in. There will now follow a period of annoyance as I rebuild my Lightwing. Arthur.