Ian

I was wondering what the best valve types and cylinder sizes for oxygen were. And is getting refills for your own cylinders available in Australia or more specifically Canberra or Sydney. The market appears to be dominated by companies only doing refills on their own cylinders. The US market cylinders have CGA-540 male fittings and the Australian market has CGA-540 female fittings. If I bought pin indexed CGA-870 valved cylinders am I going to be able to get them filled with industrial/veterinarian oxygen? There's an interesting article on the supply of oxygen here https://www.avweb.com/features/pelicans-perch-13getting-high-on-welders-oxygen/ Not sure that it's true but it's food for thought. I've always thought that the options that oxygen provides would be beneficial There are a few more articles on oxygen here https://www.kitplanes.com/homebuilt-o2/ https://www.kitplanes.com/military-oxygen/ https://www.kitplanes.com/how-to-use-your-oxygen-system/

I liked the quote that the the head of Coke made about some of the conspiracy theories about the introduction of new coke" ""We're not that dumb, and we're not that smart."

I spoke to a pilot the other day who fervently believed in existence of chemtrails and other Government/UN conspiracies to install overlords or something similar. I was a bit surprised because as a pilot he'd have an understanding of the types of infrastructure required to perform such as feat, just the the logistics alone would be incredibly difficult. As well as this being a pilot he should have a basic understanding of the weather and be able to extrapolate why some contrails will last significantly longer periods than others. The thing that really gets me is that everyone knows that Government in general has a degree of incompetence large enough to make them the butt of many jokes, so how does this seemingly incompetent organisation run this massive secret operation hidden from the eyes of the major news organisations and only facebook or whereever they get information from etc. We all deal with CASA and know what stellar performers they are like. We also saw the head of BOM trying to rebrand the organisation in the middle of a major flood so we know that they're not savants. Governments in general are prone to hubris, overreach and mismanagement, they're made up of average people by design, because we want the best and brightest people to be running business and research organisations. Wikipedia maintains a list of conspiracy theories https://en.wikipedia.org/wiki/List_of_conspiracy_theories Are views like this common in the flying community or are they the exception to the rule, I had thought that pilots, given the fact that remaining airbourne requires practitioners to be able to use critical thinking, would be less likely to side with the conspiracy theorists.

What I was alluding to is that the likelihood of losing all engines in a single birdstrike incident is far less likely. Unlike volcanic ash which is more of an environmental issue. There was a shortage of air freight capacity during the pandemic. My understanding was that freight was generally a secondary load type after passengers, less passengars = less freight.

The simplest way to stop inequality is to get rid of inherited wealth. Nothing is less capitalistic than inherited wealth as it involves gifting money to people based upon an accident of birth rather than the accumulation of capital based on ability. I suspect that there would be many more programs aimed towards innovation and wealth creation if this were the case rather than programs designed to enhance the status quo. That being said death taxes have always been unpopular. I have occasionally wondered if a 3 or 4 engined plane would have been forced to ditch given the same circumstances. https://en.wikipedia.org/wiki/US_Airways_Flight_1549

Does the Stratux provide an ADS-B out option? Having a system which doesn't provide an out is pretty limited especially if lots of people start using it.

On batteries only 250km. The 1000km is based upon some form of hydrogen cycle. I'm not sure what bits are reality and what bits are aspirational or whether the range is calculated with or without a payload. Hydrogen as a fuel is hard and "green" hydrogen is also also very hard. I might be wrong however I suspect that as an energy carrier it is mostly folly. Take the case of Hydrogen production, solar and wind are intermittent, so you need to cycle/throttle your generation process, the only electrolysers which can be throttled are PEM electrolysers. However PEM electrolysers require iridium which is part of the platinum group and it one of the rarest commercially produced elements. Current production is only 7 tons a year and it is a very scarce resource. To provide a terrawatt of hydrogen generation would require about 27 years of current iridium production and the world economy would requires about 4 TW of continual electrical production. This doesn't include non-electrical energy flows which hydrogen is meant to replace. You could use other types of electrolysers however they need to be kept running which doesn't work with intermittent sources. Hydrogen is a great fuel once you're in the air, it's weight per unit of energy is very good but production and logistics are difficult. Fossil fuel companies are hyping Hydrogen because they're the only possible suppliers from an economic perspective, but why not just use natural gas instead, it's cheap? Elon Musk chose that path for his rockets because H2 is hard and CH4 is easier and cheaper. https://aviationweek.com/air-transport/aircraft-propulsion/can-aviation-use-liquified-natural-gas-reduce-its-carbon But going down the Fossil fuel route still produces CO2 which is bad even though CH4 produces less.

Piranha solution will dissolve the deposits. However it will probably also continue to dissolve the entire piston 🙂 But it is good on glass.

Signal to noise ratio. The key issue is what is the attenuation profile of your favourite earplugs. If the plugs attenuation the higher frequencies more than lower ones, which they do, you're going to end up with muddy sound which mutes plosives and masks the temporal boundaries which we normally use to distinguish speech. Plosives have a lot of higher pitched sounds. This may not matter much if you already have some hearing loss. This is one of the reasons why, as you get old, and your ability to hear higher pitched sound diminishes, conversations in noisy places with lots of hard surfaces become increasingly more difficult. I'd be tempted to just buy noise cancelling headphones with good physical attenuation as well as active attenuation. It's hard to get published figures on these though I love to see test results so it was easier to make some value based choices.

The old Subaru engines appears to be able to cope with extended high revs at max power https://www.torquenews.com/1084/subaru-history-how-they-set-2-world-records-and-13-international-records-set-same-time-video Of course this is only about 500 hours.

P1xT1/V1 = P2xT2/V2, Bernoulli and heat of evaporation, explains why icing occurs. But the reason why carbs are significantly more prone to icing than throttle bodies or fuel injection is due to the design of carburettors. Engines with carburettor have a butterfly valve which reduces airflow and thus reduces power and creating lower pressure behind the valve. In addition carburettors utilise the venturi effect to suck fuel into the airstream, further lowering the pressure and associated temperature. https://en.wikipedia.org/wiki/Bernoulli's_principle Then on top of this is the cooling effect of fuel being vapourised. This all adds up to a significant cooling of the air below freezing, causing moisture in the air to become supercooled which freezes directly on contact with the internal carb structure. While some carburettor planes are less likely to suffer from carb ice than others, the fundamental design of carburettors makes them susceptible to icing and because fuel delivery can be impacted by small changes in the airflow cause by icing significant power loss can occur without much ice accumulating. This is a flaw of carburettors and it mitigated effectively by carb heat. Going without carb heat or equivalent poses a risk in some weather conditions. There's a good story on induction heating being required on Ellison throttle bodies in ideal icing conditions over New Guinea which is probably about as bad as it gets. https://josteve.typepad.com/blog/2010/04/the-puffin-has-landedin-oz.html

The stabilised earth floor is starting to look attractive.

The lowest cost path to getting your licence is getting your eyes tested and getting glasses. Otherwise you'll be spending lots of time booking specialist appointments and arguing the merits of your case. At the end of which they may recommend that you get glasses which correct your vision sufficiently.

You don't have monocular vision. You should get glasses which correct your vision, and you'll have a flies with glasses on your licence. And you optometrist will enjoy your company again. Probably cheaper and easier than the alternative route.

Yes you're probably right. Curved beams in wood are cheaps than steel generally, I just like the whole ww2 vintage feeling of the arched hangars. Sliding doors start off nice and over the years become more difficult and you arms need to become stronger.

Yes, you're right, however an arch type hangar, width 20m with 3x8m sheets spanning the roof, with glulam beams ~400mm deep providing support, and cross bracing using standard strapping would meet Australian standards in terms of strength and wind loads. Cyclonic wind loads or public shelter requirements might need thicker sheeting or plate attachments but that's out of scope for my needs. The centre section is spanned by a single sheet and the fall at the point of the join is well beyond minimal fall to ensure that leaks don't occur. Condensation is reduced by a vapour barrier like sarking and is the recommended way to mitigate this, birds in hangars seem to be more problematic for paintwork in practice. Solid timber maintains its strength for longer under high heat loads, however it does burn of course. The main risk from a durability perspective is probably termites and from a construction perspective finding someone willing to build the arches cost effectively to spec. An arch is more efficient in terms of steel used than a box and you can use dish drains rather than guttering so it's a bit of swings and roundabouts. You can go pretty large with simple wooden arch frames. https://internationalforestindustries.com/2019/04/17/nz-massive-new-hangar-wood/

Is would be simpler with multiple sheets not a single sheet, using three sheets, ie 2 sides and a top sheet over the crest gives sufficient expansion on GA hangar sizes. On a larger project you'd be putting in expansion joints when you exceed 23m spans. Even with a single sheet.On a 20m span you get about 12mm of expansion with a 50C temperature change which is reasonable. So about 6mm on each side which should be manageable using standard attachments and tolerances.

Not sure what you meant. Arches extend easily in along their axis, changing the span is difficult, however gabled rooves suffer from the same limitation. Is it likely that you're going to buy the neighbouring block and extend, and have a neighbour willing to sell? Is it simpler to just buy a bigger site?

Yes but that requires a custom roll and $$. Standard roofing iron is suitable for a 12m bend. Some types will do 8m without artefacts.

I worked on a number of tilt up concrete construction jobs while I was a uni student and really liked it as a building process. It was never mm accurate and there was lots of optimistic packing when the slabs were tilted. However the sites have aged better than I have over the intervening decades. I'm a bit less enamoured by concrete at the moment just because I've become a bit more worried about CO2 but there are a lot of pros. Maybe there's a grant somewhere for geopolymer using volcanic tuff. https://www.aph.gov.au/DocumentStore.ashx?id=a27746a7-775e-45c9-957a-e8ba0d2e636f&subId=565096 I was playing around recently trying to figure out if you could build the old style hangars cost effectively using glulam arches. A glumlam arch using 10MPa laminates gives about a 50:1 span capability. Standard corrugated iron has a minimum spring curve radius of about 12m so skinning uses standard materials and your height is about 6.5m. Doors remain an issue however at least you get to use some of the area closer to the boundary of your site.

What design/size hangar and door combination did you choose and would you care to share the budget?

I don't really rate your fire services engineer. This is a henny penny type argument, it is a basic infrastructure problem and it's an easy problem to solve from a design perspective, electrical engineers design standard circuit types to be deployed in these environments which are specified in Australian Standards, if a standard can't found it should designed by a qualified engineer. For example in some environments low smoke flame retardant non-toxic insulation TPE/TPU is mandated (specified in Australian Standard). Sounds like it would be suitable for deployment in an underground car park with limited insulation. (We did have a discussion earlier of whether there's a difference between a university qualified engineer with a BEng or someone who has put the word engineer in their title) The technology to solve the peak load problem exists and has been in existence for years and yes even Governments know about it. Essentially it's a modern version of off peak power but smart enough to tell the difference between I need the car charged now or I need the car charged by 9am tomorrow. https://www.smartgrid.gov/the_smart_grid/electric_vehicles.html Unsurprisingly power companies are also looking at using your car batteries to stabilise the grid https://www.agl.com.au/residential/energy/electric-vehicles/smart-charging-trial, I wouldn't participate in this unless there is a very large payback, your car batteries wear out.

The other option is experimental, especially if CASA allows non-builders to maintain. Different set of risks https://saaa.asn.au/courses/mtc-amt3-advanced-endorsements-permissions-to-maintain/

You'll have to point out the research papers which show vaccines have caused EBV in 80 people in australia. As far as I know there are a couple of cases of COVID reactivating EVB. https://pubmed.ncbi.nlm.nih.gov/35349757/ https://immunityageing.biomedcentral.com/articles/10.1186/s12979-021-00252-x However, it now seems that “long COVID” could also be related to reactivation of the Epstein Barr Virus (EBV), which lies dormant in a very high percentage of the population You may have had EBV in the past and recent illness of stress may have reactivated it. Or you simply may have been exposed to it recently. I doubt that a vaccine is going to give you EBV. It would take some pretty messy manufacturing controls for that to happen.

Below is another good video on the theory and story behind the dynamic soaring record which is interesting but a little more esoteric. Who would have thought supersonic airflow would cause a glider to crash. I just like the sound of it going through the air. In it he says that the G force meter topped out at 120G It isn't like an ordinary glider weight isn't so much of an issue but strength so it can withstand the G forces. I'm surprised that they don't crash more as it's moving so fast.