Head in the clouds

Hi Mark, thanks for your kind words. I'm delighted with the find. I've been over every inch of it in the last three weeks while doing the Periodic/Annual and I'm happy with every part of it - and it includes some very innovative and sensible design. I feel that I'm a lucky person in that regard too, because if I find things that I don't like I either have to change them or I won't feel relaxed in the air. The rego changeover came through today from RAAus so all the documentation is in order - fun times ahead. Yes, I saw Rob's float videos yesterday, looks like fun but requires a lot of help for trailering, launch and retrieval - amphib would be nice but too heavy I think. Howe, on this site also has one, and another that he's rebuilding which will be for sale soon if anyone else wants to join the fun.

Thanks ClintonB, it's always been my hope that I might occasionally be an inspiration for people with anything aviation related. Sorry to hear about the Bushbaby, I didn't know you had one damaged. If there's anything we can do to help, feel free to ask ...

Not really anything to do with the DooMaw build, but it's my thread so what the hell ... As some of you may have noticed I've had an enforced break from the build for the last six months, I just have so many other things going on. All very pleasant and adventurous things - travelling, sailing, powerboating, exploring, fishing, but not leaving enough time to get stuck into the build. All that will change soon and DooMaw will be the focus of attention again. However - I've been getting a bit concerned at how little time I've spent in the air the last few years and, of course, when DooMaw is finished - hopefully in about twelve months - I'll have the test-flying to do, and I have been wondering just how rusty my handling skills might have become. For a while I've been thinking that I really ought to try and find a cheap plane to be able to get very current again, not to mention that I really miss regular flying. I'm fortunate that I often seem to have good luck on my side - I idled away all of about half an hour looking at classified ads in Sport Pilot, ebay and Gumtree, and came across half a dozen possible projects and a couple of planes that didn't need much work at all but were probably a bit more than I wanted to spend at this stage, with several large expenses still to go on the DooMaw project. I went and had a look at most of the 'projects' and after pricing up replacement parts and new skins (Thruster TST types) it just wasn't going to be worth resurrecting them. Then there was/is a Saphire in virtually original condition with spare engines for just $7000 which was extremely tempting. The Saphire is a lovely plane to fly, I flew quite a number of hours in them in the '80s - but it just wasn't quite what I was after this time. I wanted something I could land off the airfields, and the Saphire would also be a problem finding hangarage as it didn't have a trailer. Then I came across one of my very favourite ultralights for sale, complete with its own trailer, and an owner with a very specific requirement in terms of the new owner, who would need to have lots of ultralight and taildragger time, both of which I have. To cut the story a bit shorter, I am now the proud owner of the last-built Lea Kestrel, which Cec Lea built as his own aircraft, so it has a fair bit that the earlier ones didn't, in particular being fully enclosed but can be flown with doors off, and Stitts/Ceconite covered wings and tail which are much cleaner than the dacron ones (better performance) and don't have to be replaced regularly either. It has very low engine and airframe hours but hadn't had a Periodic/Annual Inspection for a couple of years (although the engine was run, and logged, every fortnight). So I got my head into study mode and completed the L1 course and exam in a couple of days and got stuck into the servicing and developing new logbooks. I also got into the study for the RAAus Weight and Balance course which takes quite a while, there's a lot to read, did that exam as well - and failed. It was the first exam I've ever failed and I was particularly annoyed that they won't tell you which questions you got wrong. The pass mark is 90% and there are 23 questions with no time limit, but it means you can only fail two questions, I failed three. It took me four days to do the study and then 2.5hrs for the exam, so I wasn't happy. I re-read some of the course and took the exam again a few days later and passed but I still got two wrong. That meant I am an 'accredited weigher' so I could do the weighing and W&B loading schedule for the Kestrel. I'm glad I did, there were some considerable errors in the original one. So far I've only had time for one quick flight and I'm very happy with the performance and handling - more about that next time, back to work for me now and here are a couple of pics -

Scout peg -

Yes it is, on a factory-built plane. Also, that would probably be quite inconvenient if you had to access the engine bay each time to refuel, though no doubt you could run a tube to a convenient location. And ... it wouldn't work on some installations due to the one-way valve in the fuel line. And also, if you used a pump that exceeds about 4-5psi you would unseat the carby float valve and cause flooding in the engine bay, a serious fire risk. Having said that, for an amateur-built it could be a very convenient method for some people, in some installations, and help to avoid spills onto windshields and the like, which, if polycarbonate and curved, often results in instant destruction of the windshield.

Hi Doug, Would we assume that your series of questions are aimed at avoiding getting a tailwheel endorsement when the Thruster is ready for you to fly it? If so, it really doesn't matter what name you give to the landing gear, it'll still have the CG behind the mains/centre of resistance while rolling down the runway, so it'll still prefer to switch ends and depart the runway sideways unless you prevent it from doing that. With that in mind, it's very unlikely that someone will successfully takeoff and land a taildragger without training, not very often anyway ...

It requires a modification to the fuel tank(s) which is not permitted on factory-built planes and would probably be quite difficult on many fuel tanks anyway, unless they just happened to have a suitable threaded boss available at an accessible location. It 'might' be possible to use the fuel sample drain point where modifications are permitted on amateur-built planes. Otherwise you would have to tap into the tank outlet and they're often in locations that are difficult to access.

This would appear to be a good, lightweight and cheap option at $25 - 255LPH FUEL PUMP Set Fits Falcon BA BF 6CY XR6 Turbo XR8 V8 FPV GSS340 In-tank fuel pump normally for fuel injection - at that flow rate it would transfer a 20L jerrycan of fuel in just under five minutes. Just kit it out with a length of 8mm fuel hose with inline filter, a pair of wires with crocodile clips to connect to the battery with an inline rocker switch - and dangle it in the jerrycan of fuel. The pump weighs only 360g so the whole setup would be under half a kilo ... Edit - or if five minutes is too slow for you, you can get a 450L/hr pump for $70 that would transfer the jerrycan of fuel in under 3 mins.

Do you have a reference for that?

Photos are exceptionally unkind to all welds. Unless they're very even, smooth and regular they never look good in pictures, the reflections off the various angles of the surfaces where the filler rod has been dipped make them look a lot rougher than they really are. The HAZ (heat affected zone) shown in those pics is well within acceptable levels, and there's no evidence of overheating. I doubt that's a blow-through on the left, there's no closed end to the tube to have caused it, I think it's far more likely to be the weld-up where the weld was started and finished in the acute angle of the heel of the joint where much more heat is required to maintain the puddle. They're not perfect welds but I've seen, tested and sectioned very much worse ones which have demonstrated compliance for aircraft and motorsport structures.

Thanks T88!

I'm looking for some parts for a TST refurbishment - 1. Full set of wing ribs/battens - or a template to make them and info about the end fittings (are they the same as the Drifter ones available from USA? Or a local supplier of them?) 2. Pair of jury struts. 3. Set of skins - or info about people who can make them 4. Seat covers 5. Anything else people have in the back of the hangar perhaps?

Yes I agree, that is the simplest of all reasonably accurate methods. Much as I have the very greatest respect for Mr Kyle, I've not found those horizontal-shaft balancers to work at all sensitively enough. Similar to the 'suspended by a string method' - to achieve much greater sensitivity it is best to machine up a mandrel which inserts into the central hub hole, or better still, inter-reacts with the bolting circle. The mandrel should have a central drilling with an internal conical termination which accepts a spike mounted on a pedestal of some kind. Ideally the termination/balancing point should be quite low, creating a fairly unstable balance whereby the whole assembly wants to readily tip one way or the other unless the tip/tip weighting is very close. That will give the best end result for static balancing. It's also worth keeping in mind that more inboard weight on one blade will statically balance more outboard weight on another blade, so all may appear wonderful, when in fact it might not be perfect. Those who have balanced con-rods end-for-end will appreciate the notion ...

Yeah, well, it's nice to be nice about it, but it's just another example of incomplete training. Landing on a strip like that, rather than being a drop off in the runway, must be treated as an upslope landing at the other end. You cannot possibly land on the downslope part of it. Brakes have nothing to do with it, the downslope would always keep the machine flying unless you stalled it and had it pinned right at the top, and his 'technique' didn't provide that. Landing on runways with significant dips or humps in the centre require thought, consideration and applied technique. In the case of the runway shown in the video above, there should be no intention to touch down before the beginning of the upslope unless you could stop before the downslope. That means a careful approach flown over the keys, maintaining a low and slow controlled flight throughout the downslope and an unusually rapid flare to the upslope, with power application as required. AND - if it was me, I would have landed downwind instead, because the upslope that way is much greater and with practice it would be easier to stop, but the emphasis is on the word 'practice'. Hopefully we all knew that anyway ...

That's really sad to hear, of the ultralight helos the mozzie is one of the best designs and build quality, and has good handling characteristics. RIP

Lovely job. Well done!

Best wishes for you and Caitlin and the rest of the family, Ian.

That's mighty scary, because those cables fail due to wear and fatigue rather than time. Consequently a plane that flies the average private ownership hours of 20-50 per year might have 300 to 750 hours of use in 15yrs, which, in a non-corrosive environment should be fine. But a plane in a training environment or being used on a station perhaps, operating 500 hours a year, might have 7500 hours of wear and fatigue on those cables before anyone was aware that they ought to have been replaced. From personal experience, and anecdotally from many others' experiences, I would be replacing the cables at two years or 200hrs, whichever came first, if I wanted to be confident they wouldn't produce any unpleasant surprises. There's another factor that massively affects the potential life of these cables. It's the angular deflection of the ends at full control movement. In some installations it will be minimal, in others it will be close to, or at, the maximum angular deflection available. If you have a look at the punishment the liner and inner have to absorb at full angular deflection under load (i.e. down aileron, up elevator or either rudder), it's significant. And in those airframes with a harsh geometric setup, the actual punishment of the cables is further determined by the style of the person operating the controls, some are smooth and gentle, others happily whack the controls about like it's a video game.

Yup, they have a limited life. I've had quite a number of them fail in boats. Usually they fail at the engine end and then it's easy to assume that they only fail due to rust and/or the constant movement of the outboard due to tilt/trim and steering function ... then I had a few failures at the remote control end which put the lie to the rust/movement aspect, and were clearly cases of wear and fatigue failure. If I used them in a plane I would replace them every two years, they don't cost much. I fear we may see more failures as the fleet ages, I hope they have a happy outcome, like yours Jaba. Sounds like you were very lucky. I've had a severe case of flutter to the point where my (aly) I beam sparred wings were flapping like a bird's, and the onset is frighteningly rapid, as you described - this happened to me before I knew what flutter was, so I did the wrong thing, I was on final approach and instead of slowing down I put the nose down to get on the ground asap, so the violent shaking continued all the way to the ground - gladly it was a strong airframe. If your specs were shaken off I'd say you also had a case of aileron flutter induced wing flutter (not just aileron flutter), gladly the Jab wings are composite so they can cope with more flexing than one might imagine, like a fishing rod to a degree, but you'd probably do well to conduct an extensive tap test to check for delamination between the skins and the foam cores. If that has occurred it's not the end of the world, it can be fixed by injecting epoxy and using cinch straps and packers to apply clamping pressure while it sets, with a slight weight penalty. Thanks for posting your experience, I sincerely hope it encourages others to replace their cables more frequently - by the way, what is the Jabiru factory's requirement for periodic cable replacement?

It's still because the inner is smaller than the outer so under compression the inner goes into a series of esses whereas under tension it straightens out. You can't get rid of the play, and the more worn the liner becomes, the greater the play becomes, so it may be time to replace the cable. A few years ago a new series of Morse/Teleflex cables came on the market which are more flexible, have less play due to a closer fit between inner and liner, and are also smoother due to less friction because the teflon liner bore is star shaped rather than circular, so there's less contact area. They're not very expensive in the smaller sizes, about $100 for yours, so a new one shouldn't be too painful on the hip pocket.

Judging by some of the earlier comments perhaps it's WA - my 1980s WA number plate slogan was 'State of Excitement'. It was too!

Yup, you can't beat that 'bottom rudder and holding off bank with aileron', if you want to kill yourself ...

Lovely work, it's a credit to you - doing well Marty!

No, that's not so. I'd suggest that the majority of folks in Australia have regularly driven or walked on oiled roads and pathways. Unless you're extremely versed in the method you would never recognise it.The oil doesn't transfer back to the tyres, it's not slippery and it certainly doesn't 'layer and clump', whatever that is ... Whatever, like I said, it's been used successfully, unobtrusively and unintrusively for 100yrs or more in low rainfall areas, but what would the old bushies know anyway. Come to think of it - who rushes off to wash their car or aircraft with degreasing detergent after landing or driving on bitumen? There's not much difference in practical terms except the oiled road is softer and the aggregate is smaller.

It's collected and recycled in city areas but not in regional areas. Further out the service stations are still very happy to get rid of it any way they can. A lot of it gets burnt off at the tip. Quite a bit more gets used by the road-gangs when repairing potholes to soften the existing bitumen - it saves on the amount of diesel they have to use. I don't know if Soleair is far enough out for there to be a surplus of it, but I doubt it's collected for recycling further than 50km or so from a major city because there's probably not enough of it to make it viable.