skippydiesel

Interesting! I have flown into Cowra a couple, or more times - very busy during the week (Saturdays?) near dead on a Sunday. Great coffee & brownie in town. Never into Tumut - hoping to do one of their third Sunday/Month brunches, in the near future. The 126.7 frequency is an interesting issue - resent flight from Rylstone to The Oaks - as soon as I got above about 5000ft, I could clearly hear those in The Oaks/Mittagong circuit, still 30 + minutes away. At The Oaks, I often hear airfield well to the west of the The Range - sometimes so clear, that if the transmitter forgets their location component, my heart rate increases as I think there is an unseen aircraft very close - its certainly can be a problemo! 😈

Not defending/taking sides here - The Forum has a wealth of past, current & future aviation ( sometimes other) knowledge to impart. You can learn stuff, even from a self proclaimed perfect pilot/engineer - best not to use the "ignore" function if it means a loss of access. Instead use the self discipline button - do not respond!😈

Holbrook Easter Fly-in 2026 Holbrook Ultralight Club has hosted this popular annual Fly-in since 2006. Initially held on the first weekend of November, the Fly-in is now held on the Easter holiday weekend and continues the tradition of hospitality and friendliness. We welcome recreational and sport pilots and their aircraft from all over Australia. 2026 Fly-in details When: Saturday 4th and Sunday 5th April 2026. Where: Holbrook Airfield YHBK S35.41.0 E147.19.0 https://www.holbrookultralightclub.asn.au/flyin.html

Just winging it: Depending on cable material (alloys) & proximity to corrosive atmosphere (eg sea) you may have to think about more frequent replacements, just to be safe. Visual inspection may not reveal internal coorosion.

Nowhere in the World can nuclear waste be safely disposed of. You condemn, the generations to come, to radiation sickness - talk about short term gain / long term pain😈

To the best of my understanding (low bar) we ( human species) do not have a safe (as in never pollute/ irradiate, current or future generations) method of disposing of the spent fuel. Should this be correct (??)- all we are doing, is polluting our one & only home (sh..ing in our back yard) to the detriment of generations to come. ".. no brainer" might just be the way to describe advocates of atomic power stations/ weapons. 😈

IF ? you have a Constant Speed prop: Even if throttle cable broke, prop likly to remain at or close to, selected rpm. If above not true, select for courser pitch to govern rpm down to a less heart stopping rpm.😈

Very nice IBob BUT its not a canard 😈

Very pretty aircraft. The belly air inlet, directly behind the nose wheel, (kicking up stuff) look like a high risk of stuff entering the engine???😈

Moneybox, "I've soldered them into the spade terminals " Probably telling my "grandma how to suck eggs" - I have found that solder connections can be unreliable. For best security, do crimp connections & support the wires against movement/vibration.😈

Yesterday : The Oaks - Rylstone Airpark. (2hr ) Great flight. Magnificent views. Met a pilot/builder, nearing the end of a long build - Constant Speed, Retractable, Tandem Seat, Rotax 912 Supercharged (140hp). Great workmanship/attention to detail. Hot machine!😈

Just passing on this Vans warning: Aero classic tires sidewall cracking | Van’s Air Force 😈

You are correct about the Jab - remained in circuit, after a go round. The Cessna had departed Camden, upwind, runway 24, however that was some time before the incident ie no bearing on the incident. A simplified / abbreviated version of events; On Saturday morning, 26 October 2024, Weather good, although some pilots reported some turbulence - others did not. It appears that the Jab 450 (1 pilot) & Cessna 182 (2 pilots), flying in opposite directions, in the circuit, at about circuit height (1900"), collided at about midfield, due West of The Oaks airfield. All three people died as a result of the collision. I doubt if we will ever know; Why the Cessna was there What the two experienced pilots, on board, intentions were Why they appear not to have heard aircraft in the circuit Why no transmission from the C182 were heard We do know ; What the Jab was doing - after a balked landing, was in the circuit, down wind, intending to make a landing, on runway 18 The C182, originated from Shell Harber, was on a training flight With the student being assessed for CPL, by a very experienced ex airline pilot/examiner Believe that the original intention to fly, via Victor 1, to Cessnock This plan was changed and the flight altered course at or about Long Reef, flew inland to connect with the southbound Lane of Entry, Departing the lane of Entry, headed for Camden, where several circuits (1800'), TAG's, & a glide approach were flown, before departing runway 24, not above 1300' (all with permission from the Tower) West towards The Oaks There is a much longer more detailed official report - doesn't change what I have just summarised.😈

It seems to me, if using the exhaust heat (there are other option), you would take the heat from where you will get the best result (volume & temperature of hot air). If the builders have determined that the exhaust pipe, rather than muffler will deliver what they want - all good. Using the exhaust system to heat cabin air is the tradition method , with the known potential for CO poisoning & transmission of engine noise. Safer quieter alternatives are available. Alternatives heat sources that seem to be viable are - Cooling System (hot liquid) Coolant Radiator (air) and Oil Cooler (air). The Cooling l system can be plumbed and controlled much like a car heating system but requires additional hoses, valve , small heat exchanger and fan. Likely to be relativly heavy & complex compared with the other systems. There is no chance of CO poisoning. As heating will be tied to engine temperature, may be slow to get going. Coolant Radiator - I have seen a design where hot air is taken from the back of the radiator & reticualted in a similar way to the exhaust heated air . The upside to this is no chance of CO poisoning. Once again may be slow to get going. Oil Cooler - similar to the above. A the use of thermostats, in all of the above, would speed hot air delivery and may make the system less prone to temperature drops, when at low power (descent)😈

I see this idea promoted quiet a lot on the Rotax Owners Forum. Cant see the need myself. At the rate I accumulate hr's an oil drain only happens once per annum, in a good year a possible second. Hardly a challenging workload. The drain plug should not be tightened any more than necessary to crush the washer (Rotax will have some ridiculously low torque setting , wrist "click" will do me)- easy to see & do. The plug is then safety wired to the base of the tank. - no chance of comming undone.(I have never had a leak from the oil tank). Removal is a doddle - remove safety wire and using two spanners "crack" the lightly torqued plug. Its now finger tight but a tad hot to actually use the fingers, so continie to loosen with one spanner. Put your old oil receiveal container up as close to the bottom of the tank, as is constant with doing the job/access - this will reduce the chances of spillage. I use roofers soft aluminium flashing (Bunnings Aerospace) formed into a channel & hooked over the engine frame, to direct the oil into a calibrated container (I like to record oil quantity removed, then added). It's annoying but of little concern if the plug drops into the hot oil - magnet will fish it out. I am not against the oil drain valve - have one fitted to my Ranger sump. The Ranger requires removal of bash plates, before loosening the drain plug and then the position of the drain means oil hits a cross chassis member & splashes everywhere (nasty!). The drain valve & short hose prevents, all that mess & the need to remove bash plates- a no brainer!😈

Thanks Thruster, Will look into the Silicon tubing, looks promising. As you suggest, IF it is a tight fit, security clamping at just one end may be acceptable. Float bowl breather tubes are plumbed into the airbox (same air pressure at carby inlets). The airbox has drains that exit into a temporary catch can, so that any fuel leak can be monitored.😈

I see this idea promoted quiet a lot on the Rotax Owners Forum. Cant see the need myself. At the rate I accumulate hr's an oil drain only happens once per annum, in a good year a possible second. Hardly a challenging workload. The drain plug should not be tightened any more than necessary to crush the washer (Rotax will have some ridiculously low torque setting , wrist "click" will do me)- easy to see & do. The plug is then safety wired to the base of the tank. - no chance of comming undone.(I have never had a leak from the oil tank). Removal is a doddle - remove safety wire and using two spanners "crack" the lightly torqued plug. Its now finger tight but a tad hot to actually use the fingers, so continie to loosen with one spanner. Put your old oil receiveal container up as close to the bottom of the tank, as is constant with doing the job/access - this will reduce the chances of spillage. I use roofers soft aluminium flashing (Bunnings Aerospace) formed into a channel & hooked over the engine frame, to direct the oil into a calibrated container (I like to record oil quantity removed, then added). It's annoying but of little concern if the plug drops into the hot oil - magnet will fish it out. I am not against the oil drain valve - have one fitted to my Ranger sump. The Ranger requires removal of bash plates, before loosening the drain plug and then the position of the drain means oil hits a cross chassis member & splashes everywhere (nasty!). The drain valve & short hose prevents, all that mess & the need to remove bash plates- a no brainer!😈

If anything the airbox arrangement makes carby ice more likly, than conical filters sucking warmed air. As you noted, the manifold heaters (claimed to prevent icing) are part of the existing system. My last 912 with just conical filters, never even hinted carby icing. (This is not a claim that Rotax 912's do not experince carby ice) When I was trying to isolate the cause of my leaking carby bowl breathers, I ran the Rotax conical (pod?) filters - no leak. Hot inlet air, will have some (?) performance loss implications. I agree, likly small, however this is not the only consideration. A lot of work & cost, went into the existing air box. One of my flying objectives - economical (fuel used for NM covered) touring, so no unnecessary fuel consumed (throttle setting). Together ,this means that it would take a genuine safety or performance issue, for me to ditch the airbox. The photo I posted was of the unfinished item - now looks a lot more professional, sporting a black satin look, heat resistant, ceramic, finish. I have no complaints about the airbox performance - now that it's not using the carbys for part of its support system. The clearances, due to limited space, is a minor problem that only impacts on my choice of airbox to carby duct, the topic of this thread /discussion😈

BurniM & RossK, Looks like the same iPad bracket that I had in the Zephyr - worked well. I did modify it a bit, by drilling extra holes in the back to facilitate better air flow from the eyeball vent - don't actually know if this improved things or not, as the fitting of a dedicated vent coincided with cooling mods - no further overheating occured. I don't like suction mounting systems - they seem to pick just the wrong moment to let go. I do use them to place the device (?) in various locations around the cocpit, decide on the best, install a fixed ball for security.😈

Originally the airbox was mounted/supported on engine & both carbys - far too rigid. As you may know the carbys have a "rubber" inlet manifold section, specifically to minimise the effects of engine vibration & movement on the carbys. The above arrangement was effectively negating this system. The airbox now has two supports on engine itself - one a vibration isolator, the other a saddle - the idea being the airbox weight is no longer on the carbys but still moves with the engine. Not sure but think the Rotax OM airbox & ring gear are attached. The airbox is far enough back from the carbys to have a longer /more flexible connecting duct/hose. To minimise the potential for restricting the inlet manifold rubber flexing a very flexible duct/hose between carby and airbox needed to be found. SCAT, with wire in place, was tried however the small gap (10-15mm) between airbox & carby meant that the wire effectively removed the ability of the two fixtures to move independently. Removing the wire solved that problem. I do not believe there is a risk of the existing modified SCAT comming adrift - I have had one significant engine start/movement event - duct stayed in place. My last aircraft ATEC Zephyr, used the two conical Rotax filters - worked well. (Maxed out at about 125 Kt - Normal /Eco Cruise 100-110 Kt Indicated) The Sonex is a significant step up in performance - outside/cool air supply to the engine, is part of this. (Max Cruise 152 Kt True - Normal/Eco Cruise 130 Kt True)😈

Onetrack, "......airbox that doesn't have a satisfactory connection arrangement to the carburettors." Satisfactory?? depends on what you mean. The solution I have works, it's just not as elegant as I would like. As a whole the engine installation, is what it is - it actually works very well - not perfect but then what is? The not insurmountable problem (carby to air box ducting) is "chicken feed" in the scheme of homebuilt problems that can arise. I have a working fix that has served successfully or about 100 hrs now. I did replace it at the 200 hrs service , as I don't know how durable it may be over time. Certainly I would like a better fix - a durable hose/duct similar to SCAT but without the reinforcing wire. I don't like modifying the SCAT - I am concerned by the potential for damaging the fabric and the much lesser esthetic result (looks unprofessional) As mentioned earlier, Sonex have recently come up with a Rotax 912 adaptable "ring mount" engine , which would likly result in a far better/more space in the engine bay - way to late for my build which has now been flying for 200 Hobbs hours.😈

It actually works very well - Appearances, lack of convention, whatever is spurring you to make negative commentary, is jumping to a conclusion that you have no practical basis for.

Hi BurnieM, I apologise if I didnt not articulate my need in a more comprehensive manner. My airbox is a home made unit. It features a forward facing "horn" to the front R cowl inlet (fresh, cool, possibly pressurised air) My Rotax 912ULS is installed in a Sonex using an Aerovee/Rotax adapter - makes for very tight engine to firewall space (Sonex have recently come up with a Rotax style "ring mount".) The duct that I am discussing is between airbox & carburettors. The space between carby inlet & airbox outlet, is about 10-15mm (not counting the mounting flanges ). Previous ducting was a thick walled "rubber" hose. I had a problem with the carby's ejecting fuel, from the float bowl, through the bowl breather. After much trial, error & debate (mainly on Rotax Owners Forum) the fuel problem narrowed to the carby vibration/movement isolators being impeded by the connection to the airbox. The solutions; # Take all airbox weight off carby(s) # Fit a more flexible duct between airbox/carby, has worked. The more flexible duct, I am currently using is the aforementioned, modified (wire removed) SCAT . The wire removal damages the fabric. Great care is need to avoid punctures (wastage). After wire removal the surface looks a bit tatty & may have been weakened. My only reason for raising this topic is in the hope that someone can recomend a SCAT like ducting, that would deliver a better more durable finished product.😈 This is a build stage photo (now has Hobbs 200hrs) shows test fit of airbox & inlet "horn" Note: how close air box flange to carby flange.