Dafydd Llewellyn

I'd not tackle anything major on a Jab OR a 912; though I've fully rebuilt many a car or light truck engine; there are too many subtle little tricks and special tools involved.

Nev, you're a comfort. My kids were allowed to use the car (on our 5-acre block, west of Sydney) to take the rubbish to the incinerator, which was a couple of hundred yards from the house - only in first gear - as soon as they could fully depress the pedals. They could do 3 - point turns with a trailer, by the time they were fourteen. I put both of then through to solo in gliders before they were allowed to take the car on the road, so they got the feel of being responsible for their own lives, in a disciplined environment; and I taught them to analyse what the driver in the car is front was thinking, by the way he drove - and to generally drive "ahead" of the vehicle. We moved to QLD when the younger one was seventeen; purchased a 1 1/2 ton Nissan light truck & built a pantechnicon on it, and it took 28 round trips to move our stuff to QLD; they each did a couple of trips as co-driver with either me or my wife, then we took it in turns. They were both very competent, but I didn't know about that risk processing thing Vs age, of course. They didn't scratch the truck; and you certainly had to drive well ahead of it in places like Moonbi and Murrurrundi Gap. It worked for the elder boy, but not for the younger; he had a very serious accident at 18 and later wrote off several vehicles through going to sleep at the wheel - didn't seem able to know when to stop. Nowadays, we're both in our '70s; my wife owns the Blanik, and is the maintenance controller. She has about 60 hours in gliders and a restricted PPL; she's currently at Keepit doing a refresher course, because it's been a while since she did any flying; and I'm the GFA inspector. The Blanik is full dual control, with dual instrument panels, including the engine instruments and control of the VHF COM, and we will alternate as to who is in which seat, just as we do in cross-country car trips. The one in back navigates with paper, and manages the refreshments; the one in front uses the ipad. So we'll be flying as long as we're physically fit.

You recall incorrectly. And the legal term is "certificated" (i.e. issued with a certificate); look up the regulations. If you do not comprehend that there is a difference between CASA and the automotive arm of the Department of Infrastructure and Regional Development, it's about time you did. The Jabiru 2200 J and 2200C were certificated by CASA; see for example http://www.casa.gov.au/wcmswr/_assets/main/casadata/cota/download/ve501.pdf Nobody but CASA has the authority to issue a Type Certificate. I was involved in quite a few of the aspects of the type certification testing of the Jab 2200J; but I did not do any of the finding of compliance. The Type Certificate is a certification BY CASA that the product complies with a specific design standard (product safety standard). I strongly suggest you read CASR 21 subpart B before you make this sort of pronouncement. POST EDITED AS IT DOES NOT ADD VALUE - MOD I have no commercial interest in Jabiru or anything Jabiru does, and no say whatever in the management of the company; I've simply been used by them as a consultant from time to time - mainly in regard to flight testing, but also in helping to run the J2200 engine certification tests. Those tests were run under the observation of about half a dozen CASA engineers, who were on-site for about a week. POST EDITED AS IT DOES NOT ADD VALUE - MOD

Good question. Next question?

It doesn't need a "Committee to re-invent the Wheel"; the regulatory options are all set out in CASR Part 21. IMHO, LSA is a dead-end, for the reasons JJ has mentioned. The "Solid" way is via Supplemental Type Certificate modifications (CASR 21 subpart E). You have only to look at the plethora of STCs approved by the FAA to see how important this mechanism is; but it's not available for LSA aircraft.

I've no issue with people reporting problems - that's certainly what a forum like this is for. POST EDITED AS IT DOES NOT ADD VALUE - MOD The best way to help existing Jab owners is to provide an engine rebuilding service that deals with such issues as Ian Bent has identified; that's what Maj evidently saw (and did not comprehend). The advantage of doing it that way is that there would be no legal hoops to jump through about putting it into an existing airframe, because it's legally a Jab engine with approved modifications. Of course it still looks like a Jab engine; it still IS legally a jab engine, however the product liability would be divided between CAMit and Jabiru in some way according to the modifications, and that may well be a bone of contention between CAMit and Jabiru. If that approach is blocked by the product liability issue, then the alternative will be for CAMit to go the whole nine yards, and certificate an engine containing the lessons from the Jab engine, plus a few more fundamental changes. That would probably produce a better engine still, but it then involves an STC to put it into certificated airframes; and it would still need Jabiru's "No objection" response to put it into LSA airframes. So, where to from here? That depends on some resolution of the product liability issue; and some other commercial aspects on which I cannot comment. But sniping at Ian Bent's attempts to come up with an overhaul program for existing jab engines to incorporates improvements - many of them too subtle to be obvious - for what would remain fundamentally a Jabiru engine - on the basis of "that's not the way Grandad did it" (or any other similar bar-room wisdom), is not helpful.

POST EDITED AS IT DOES NOT ADD VALUE - MOD Point 1: Lycoming and Continental crankcases are made from 355 alloy, which is an aluminium/copper alloy. It starts out in the -T6 heat-treat condition; but it slowly loses strength due to the operating temperature. How do I know? Because I approved a new weld repair process for those crankcases (after a lot of research, done by Rudi's Aero Engines, in conjunction with my son Bob, who was acting as my junior engineer at that time. It took a lot of testing to convince CASA). They usually need weld repair sometime during the second engine life; and by about half way through their third life, they are down to close to dead soft, with weld repairs all over the place, and should really be scrapped. Those cases are sand-cast, NOT forged. They are heat-treated after casting and before machining; thus they have locked-in stresses that may be released during machining, too. The principal problem with cast crankcases is porosity; however a billet case uses wrought material, which eliminates the porosity. There is no wrought equivalent of 355; so Jabiru used what they could get, i.e. 5083. I've not heard of Jabiru crankcases cracking in service, tho no doubt they would if they were run long enough; the principal service problem seems to be indentation of the cylinder flange seat, due to flexure of the "ears" of the cylinder flange, which contributes to(but is not the sole cause of) the loss in through-bolt pre-load. That's not a crankcase design issue; it's a cylinder design issue, which CAMIT has addressed. The Jab. crankcase does not normally get sufficiently hot for thermal instability to be an issue; and it does not start out in a high heat-treat condition. CAMIT have extremely accurate measuring apparatus which runs continuous sample checking, under computer control, so it's not fussy how many dimensions it has to check. Point 2: Jabiru cylinders are machined from 4140 steel, which is a high-grade chrome-molybdenum steel containing 0.4% carbon. In what way does this differ from the material used in Lycoming cylinders? 4140 can be nitrided, as are Lycoming cylinders; however the Lycoming 0-320-E2A engine used in early PA 28-140s had non-nitrided cylinders, being intended for flying school use. I had one; it retained excellent compression right to the end of its overhaul life - but I made a point of doing a couple of circuits in it at least once a week, as recommended by Lycoming. Lycoming cylinders, including the nitrided ones, ARE prone to corrosion unless they are in frequent use; they used to sell chrome-plated cylinders for private-owner aircraft that did not get regular and frequent use; however they've stopped doing that. The crankcase is, unfortunately, NOT the only common denominator in the through-bolt saga. CAMit are focussing on solid-lifters because the routine checking of valve clearances is the best way of monitoring cylinder head and valve issues.

For what it's worth - aircraft that need to be able to fly slowly - which includes all ultralights that have a restricted stall speed, and gliders, which have to be able to turn with a small radius of turn, to stay in a thermal - have highly cambered wings. A highly cambered wing wants to turn nose-down - in technical terms, it has a negative pitching moment. That pitching moment increases in proportion to the square of the speed; so the download on the tail to balance it also increases in proportion to the square of the speed, which generates considerable structural loads. The tail load also increases the tail induced drag, and since the wing has to carry the tail load as well as the weight, it increases the wing induced drag a bit, too. If the wing uses a laminar-flow airfoil (as gliders do), there is a second effect; laminar airfoils have a reduced drag over a limited range of angle of attack; this is sometimes referred to as the low-drag "bucket" because of the shape of the lift/drag curve. Outside that "bucket", laminar airfoils usually have a higher drag than the conventional airfoil on the jabiru etc. Reflexing the trailing-edge surfaces moves the low-drag bucket, and can therefore increase the usable speed range in which low drag occurs. Both these things can be a reason for the designer to use "variable camber" via symmetrical movement of the flaps and ailerons. Doing so helps keep the fuselage close to its minimum-drag angle. However, the total performance gain is relatively small - and it greatly complicates the task of certification, because all possible geometries have to be investigated. An example of this was the Pik-20B glider, which had a crank-handle on the left of the cockpit to change the wing camber. The sensation that gave the pilot was spectacular - on leaving a thermal, one did not shove the stick forward to gain speed, one wound the crank, and the airspeed shot up with no perceptible change in attitude - it was almost as though you were cranking the ASI needle around the dial. However, the actual performance was really much the same as its contemporaries without this feature; it just felt faster. Most current gliders use it, to squeeze the last bit of performance - tho I wonder whether it's more a case of squeezing the last dollar from the consumers.

Earhart's aeroplane was a Lockheed 10; same No. of wing, engines, and tails as a Hudson, but certainly not the same airframe.

See australian standard as/nzs 2906 - fuel containers - portable - plastics and metal - it does not appear to address electrical conductivity.

I've used plastic funnels to refuel various pieces of machinery around the place, and I've been lucky, too. I suspect there are two mitigating circumstances - firstly, the flow rate is small (and so is the total quantity of fuel). Secondly, there's a rather over-rich fuel vapour/air ratio in the area where sparking is most likely. But on the other hand, I've seen several hideously-burned acquaintances over the years - so it does occasionally happen. I suspect you will find that the Australian Standard for plastic fuel containers may specify a minimum conductivity; and maybe an intelligent maker of fuel funnels would use the same material - but that's a guess. I think the aviation requirements for refuelling aircraft are the result of WW 2 experience; putting a couple of thousand gallons into a Lancaster or whatever in a hurry, is far more likely to build up a dangerous static charge, than pouring 40 litres into an ultralight. However, stainless steel hardware is much easier to get, nowadays, and it's cheap insurance.

I think it's more important to ground the aircraft to the refuelling equipment; however grounding that to Earth would seem cheap insurance. Bit of a challenge to do that for a mobile refuelling rig, though; you plan to drive a metre-long copper-plated steel rod into the ground to serve as an earthing electrode? Don't let the groundsman spot you doing this . . .

Getting back to the question of why were some manufacturers or aircraft disallowed (for want of a better word), the answer may be found in CASR Part 21.186.1(a) and CASA AC 21.42 - in particular, the latter, which explains what it takes to become a manufacturer of LSA aircraft. Amongst other things, the manufacturer needs to either (1) hold a Production Certificate for an aircraft of comparable complexity, OR (2) must have the services of professional persons acceptable to CASA. See http://www.casa.gov.au/wcmswr/_assets/main/rules/1998casr/021/021c42.pdf

I used to refuel my Auster - which I used to fly to & from work at Hawker de Havilland at Bankstown, in the '60s - from a metal drum (half a -44) in the boot of my car, with an all-metal hand pump, a metal-mesh filter, and the hose had a steel spring inside it, in contact with the fuel; plus I had an earthing wire from the set-up in the boot, to the aircraft. The only problem I had was that the pump and the spring inside the hose were not made from stainless, so they rusted, and of course so did the drum - and though the filter caught the rust particles from the pump, the ones from the hose made it into the aircraft fuel system (where they were caught by the gascolator). It's not difficult to get stainless steel mesh that will stop water; and this is a much safer option than using a chamois, and plastic funnels etc are simply asking for trouble. Pick your hardware with care for these issues, and you can make a very satisfactory refuelling rig, for no great cost. But don't use galvanised steel; use stainless, or if you can weld it, aluminium for the non-wearing parts. A time-ex LPG tank from a car makes a good basis. However, it's probably illegal to do such things these days, except on your own property.

You are entitled to your opinion. I'm simply pointing out the requirements of the design standard to which the J 160 was certificated. If somebody wants to re-paint one of those, that's a modification and it requires approval - and approval requires compliance with the design standard. Go argue the toss with Darren Barnfield.

Nothing funny about it at all - that's because the composites in those aircraft are generally made with pre-preg, and cured in an autoclave - whereas Jabiru use hand layup, ambient temperature cure. Pre-preg stuff comes out like bone china - and it's about as brittle as that, too. Ideal for short-life aircraft where performance is more important that anything else.

Not as far as I am aware - and the design standard makes no allowance for that.

The Tg can be increased by curing the resin at an elevated temperature, depending on the resin. The scope for this is pretty limited for LC 3600. Jabirus - at least the models I'm familiar with - are not cured at elevated temperature, because doing so also makes the resin more brittle; they do cure progressively by natural ageing, so the Tg will increase as the aircraft matures - but not indefinitely, and the process is not quantifiable. Alan Kerr was of the view (based on numerous tests) that this practice considerably increases the fatigue resistance of the layup, and also its impact resistance; some of Jabiru's crashworthiness is likely due to this. I am not aware of any research done by the African or American vendors to justify darker colours, tho presumably they have some experience by now. The weave becoming visible is a consequence of long-term resin shrinkage and is a characteristic of GRP in general; it is usually disguised by including a layer of surface tissue on the outer surface of the layup, but that adds considerable weight, so it's a luxury small aircraft cannot usually afford.

The Tg (glass transition temperature) issue is the temperature the thing gets to, standing in the sun. I doubt it matters whether the colour is painted on or stuck on. I can only suggest putting some temperature sensors on the top & the underside, parking the aircraft in the full sun, and recording the temperatures over a reasonable range of sun angles. Here's the part of AMC VLA 613 c that I couldn't attach last night:

No; you can paint aluminium any colour you like.

The Jab is white for a reason. Ever hear the term "glass transition temperature" for an epoxy resin laminate? I suggest you look it up, before you add much in the way of a colour scheme. The Jab is made using LC3600 resin. The structural testing was conducted at or slightly above 54 C, because that's the temperature considered necessary for a white-painted surface in full sunlight on a nominal 37 degree C day at sea level. AMC VLA 613 © Material Strength Properties and Design Values (Acceptable Means of Compliance) Test Temperature – a. For white painted surface and vertical sunlight: 54°C. If the test cannot be performed at this temperature an additional factor of 1·25 should be used. b. For other coloured surfaces the curve below may be used to determine the test temperature. Curve based on: NASA Conference Publication 2036 NASA Contractor Report 3290

More truth in that than you may think; flying gives you an incentive to look after your health. I started flying 51 years ago; still learning. When you stop learning, it's time to quit.

Civil Aviation Order 20.18 Appendix I Instruments required for flight under Visual Flight Rules (Limited to aircraft specified in subsection 3 paragraph 3.1) 1 The flight and navigational instruments required for flights under the Visual Flight Rules are: (a) an airspeed indicating system; and (b) an altimeter, with a readily adjustable pressure datum setting scale graduated in millibars; and © (i) a direct reading magnetic compass; or (ii) a remote indicating compass and a standby direct reading magnetic compass; and (d) an accurate timepiece indicating the time in hours, minutes and seconds. This may be carried on the person of the pilot or navigator. 2 In addition to the instruments required under paragraph 1, aircraft, other than helicopters, engaged in charter or aerial work operations and operating under the Visual Flight Rules, shall be equipped with: (a) a turn and slip indicator (agricultural aeroplanes may be equipped with a slip indicator only); and (b) an outside air temperature indicator when operating from an aerodrome at which ambient air temperature is not available from ground-based instruments. Appendix IV Instruments required for aeroplanes engaged in: (i) aerial work and private operations under the Instrument Flight Rules (including night V.M.C.); and (ii) charter operations under night V.M.C; and (iii) Instrument Flight Rules freight only charter operations in aeroplanes with maximum take-off weight not greater than 5 700 kg. 1 The flight and navigational instruments required are: (a) an airspeed indicating system; and (b) a sensitive pressure altimeter; and © (i) direct reading magnetic compass; or (ii) a remote indicating compass and a standby direct reading magnetic compass; and (d) an accurate timepiece indicating the time in hours, minutes and seconds, except that this may be omitted if it is carried on the person of the pilot or navigator; and (e) a rate of climb and descent indicator (vertical speed indicator) for other than night V.M.C. flights; and (f) an outside air temperature indicator; and (g) an attitude indicator (artificial horizon); and (h) a heading indicator (directional gyroscope); and (i) a turn and slip indicator except that only a slip indicator is required when a second attitude indicator usable through flight attitudes of 360 degrees of pitch and roll is installed; and (j) means of indicating whether the power supply to the gyroscopic instruments is working satisfactorily; and (k) except for aeroplanes engaged in night V.M.C. flights, means of preventing malfunctioning due to either condensation or icing of at least 1 airspeed indicating system. 2 The instruments specified in subparagraphs 1 (a), (b), (e) and (k) of this Appendix shall be capable of being connected to either a normal or an alternate static source but not both sources simultaneously. Alternatively, they may be connected to a balanced pair of flush static ports. 3 Except for aeroplanes engaged in night V.M.C. private and aerial work operations the instruments specified in subparagraphs 1 (g), (h) and (i) of this Appendix shall have duplicated sources of power supply unless the turn and slip indicator or the second attitude indicator specified in subparagraph 1 (i) has a source of power independent of the power operating other gyroscopic instruments. 4 A gyro-magnetic type of remote indicating compass installed to meet the requirements of subparagraph 1 © (ii) of this Appendix may be considered also to meet the requirement for a heading indicator specified in subparagraph 1 (h) of this Appendix, provided that such installation complies with the power supply requirements of paragraph 3 of this Appendix.

I don't think the non-sensitive ones are acceptable. See CAO 20.18

Yep. The 3000 ft / revolution ones are an adaption of 1000 metre/revolution. Ta - I don't get to play with that kind of hardware. In a glider, one normally taps the altimeter with a finger to see which way the needle moves, if you're in marginal lift. But I don't think that the incorporation of a vibrator defines a "sensitive" altimeter; if it reads 1000 feet per turn, it's a "sensitive" altimeter.