Ian

Why do you think this? Hydrogen is hard and physics is physics. It's telling the despite the investment this paper written in 2005 is still represents the status quo. You mention carbon fiber tanks and cryogenics. Carbon fibre gives the lowest weight and the technology is pretty simple. However the energy density is pretty poor even at 10000psi (Which isn't in production outside of a lab). Cryogenics is refrigeration. How is a car or plane going to store things at -252.9 (boiling point of liquid hydrogen) for weeks on end? Even if you think that cryo-compressed H2 is an option how do you keep it cold because as soon as it warms up it will expand and offgass or burst the tank. Either one doesn't sound safe. Here's another graph which show volumetric density which nobody wants to talk about. Liquid Hydrogen makes ethanol look good and everyone knows that ethanol reduces your range. The only way Hydrogen will work as a transport fuel is if someone develops a portable fusion reactor.

My understanding that range and altitude weren't related if the engine can be throttled efficiency (which piston engines can and turbine can't) Greatest efficiency occurs at a particular angle of attack and that determines greatest range. Jets fly at altitudes which allow the engines to function efficiently. The first paragraph explains that an understand of these principles isn't included in the US syllabus or to my limited understanding the Australian one. Piston Airplane Cruise Performance.pdf

Change is a constant as much as it hurts at times. One of the hands on my uncle's farm hands used to moan about how unjust the drink driving laws were when he only drove from the pub down dirt roads on the way home. I don't think that many people would take his viewpoints with much sympathy today. Getting caught up in the edge cases is also problematic, however what is clear is the for most people, most of the time EVs will work and are at present the most cost effective solution. From a business perspective edges cases are suicide you're either caught in a niche or trying to solve an unprofitable loss leader. My main concerns relates to intermittency of wind and solar, both cyclical and random. How much oversupply do you need, how much dispatchable power to you need to throw into the mix, and the what fuels these systems batteries/gas/gravity or momentum. One of the reasons that I thought systems like Molten Salt Reactors might be viable was their innate load following capacity. If I had a couple of billion to spare, liked dealing with dumb bureaucracies and wanted to waste a couple of decades, I might be tempted to go down this path. The other benefit for countries like Australia is that we don't have an an existing nuclear fuel industry to gum up the works. But that's just me because I'm one eyed when it comes to tech. I'm crushed about fuel cells, I've always thought that the only chance for hydrogen was this pathway. Scratching a bit more a 30KW fuel cell you're looking at 125kg, so light plane is looking at about 600kg just for a component of the engine. Relating the conversation back to planes could anyone bolt one of these onto their plane? It would probably run a treat on biodiesel

While Hydrogen may play a part in low emission steel production, it's hard to see it being used as a transport fuel. As a storage medium its less efficient than using compressed air. Storage is hard, to get around this you have some people promoting ammonia as the solution however handling ammonia is difficult and it has a low energy density. There are also people promoting hydrogen saying that we can just substitute hydrogen for natural gas. However this is harder said than done, from the following link Energy during peak generation periods is likely to get very cheap as solar generation outstrips demand. However energy intensive plant for manufacturing things like fuel tend to need to run 24x7 to make a commercial return. I suspect that the people who are promoting this either have vested interests like Twiggy (who wants the government to fund his steel operations) or can't do maths. My view is that even if you don't agree with climate change the rest of the world does and you're going to lose access to your cheap dinosaur fuel. What are you going to run on in the future? I don't think it will be hydrogen so what else out there can you buy that's economical. On that note I might fire up my still and light my pipe and start bootlegging to all you pilot types. Maybe it will fund my next plane...

The view that climate change is wrong is slowly being crushed by real science, because the issue appears to be real. Doing a little bit of "reading" rather than opining you might find that the IPCC was created by the US Government's lobbying to counter the impact of the unrestrained views and opinions of independent scientists allowing a political component to the views. Real science and research is slowly pushing the doubting Thomas' and vested interest groups into submission. The IPCC has no power it is simply a platform which is actually using aggregate research to provide a consensus point of view. It's not made up of EU bureaucrats and has the support of 99% of scientists. You make it sound like these people have nothing better to do, they do. The simple fact that your views are based on a spurious grasp of science and research is disturbing however I'll try to correct them. Climate records, justified by strong science go back millions of years. The closer you get to the present day the more accurate these records get. Nature is a Science Journal which is a good place to start https://www.nature.com/articles/nature.2016.20673 Again the IPCC provide an aggregate view of the current scientific consensus, watered down by politics. The real world is one where opinions are based on fact and extrapolated models. Yes models may be wrong but they get better over time. When you make statements like this back it up with a link to a journal, Government website or other source would be helpful. But please no facebook sources 😉 Here's a good source https://www.newscientist.com/article/2258774-air-pollution-linked-to-greater-risk-of-dying-from-covid-19-in-the-us/

The IPCC document is one of the most heavily politicized documents on the planet and has upset numerous scientific contributors in relation to the watering down of their research and comments. Every single version has undergone significant watering down of the projections. Never once has it gone up. However slowly the message has been getting stronger. https://www.politico.eu/article/leaked-documents-show-major-polluters-try-to-water-down-un-climate-report-cop26-climate-change-co2-greenhouse/ Fundamentally this is because the message significantly impacts the bottom line of large polluters who have large budgets. One of the key tools that police use when investigating crime is simply to follow the money, people lie however money finds the shortest path. Who do you trust, the dirt farmer or the city salesman, because the city sales guy is the one getting the cash.

Hi All, Engines generate a lot of waste heat and was wondering if anyone was aware of using the areas of the wing that tend to ice up to remove this heat rather than a stand alone radiator. I think that one of the supermarine planes used this approach. The Mosquito used wing radiators however they were actual cavities. Would this stop icing and would it produce thrust/additional lift?

It's not a growing question, and yes there will be consequences. It's pretty much that simple, the more you read the worse the story gets. I think that you're going down the same path that people went down in the late 1990s and understanding the difference between trends, and individual measurements. Anyone can cherry pick a few points on a graph and say see. However generally those same people don't change their mind when this is pointed out to them, people tend to believe what they want to believe. I don't want to believe in climate change however the weight of evidence forces me to do so. I keep looking for something to make it not so however the case has been getting stronger and stronger. However don't believe me do some research. If you go to the present day with the most recent NASA graphs you see the following. On my trust scale I generally trust people in NASA when they publish things. I used to work in CSIRO a long time ago and I generally trust the people there. Scientists in general could no more engage in a conspiracy than they could keep their mouths shut when their political masters tell them to. As an aside that's why the military generally distrusts scientists, and far more scientists and mathematicians fail the "security" personality tests than the general population. Now I don't know what the end result of increasing CO2 levels however the general consensus in the scientific community is that it will be bad, both locally and globally. Occasionally I wonder if there will be net winners such as greenland or Australia if there was a permanent La Nina cycle, however things will generally get worse. For example there is a chance that the additional heat in the system will force the climate into a permanent El Nino cycle, is that a bad thing? There's evidence of this occurring in the past. People concern themselves saying that biofuel use land that could be growing food. If sea levels rise the loss of high productivity agricultural areas will be enormous. For example using the IPCC projection https://www.ipcc.ch/srocc/chapter/chapter-4-sea-level-rise-and-implications-for-low-lying-islands-coasts-and-communities/ there's going to literally be a world of hurt. A lot of people in the anti-climate change camp firstly moved into the denial based approach and then later moved into the "is some CO2 and warmer weather going to be that bad". There are no concrete answers however the general consensus is that it will be really bad. Even if you don't buy into global warming, ocean acidification due to CO2 will disruption entire ecosystems as things like coral reefs are no longer viable. https://ocean.si.edu/ocean-life/invertebrates/ocean-acidification https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3960890/

My baseline assumption is that that the price of fossil fuel will be the base cost plus the cost of extraction of that much CO2 from the air and convert it into a stable long term solid or liquid. Most transport will go the way of electric vehicles, those that can't will continue to use liquid fuels at a higher cost. At that price premium some other fuels that don't have to pay the extraction tax will start to look attractive. Hopefully there will be a degree of innovation which facilitates lower costs in this area. I don't know however it will put a floor under oil crops. You're right about production areas and hopefully there'll be enough very cheap electricity to produce it via another mechanism however the processes at the moment are pretty expensive. Basically there'll be a small pool of liquid fuel otherwise. I think that if the whole greenhouse gas issue was going away it would have done so by now instead of slowly gathering momentum. You have some of the biggest industries and budgets on the planet trying to stop it and they've failed, however they did slow the process down an awful lot. While you seem to demonize city dwellers, I just prefer intelligent rational individuals and would like to demonize stupidity and people who believe in magic over maths. Basically I'm happy to let you believe whatever you want as long as I don't have to pay for it. For the anti-vaxers out there I'd like to see the people being hospitalized having to pay their own medical bills.

I would like people to put some effort into their opinions rather than telling me about how on day a rock fell from the sky, hit them in the head and that it means the world is ending. The statement quoted below was simply incorrect. If you make a poorly thought out comment that is easily refutable then so be it. Agriculture is a business just like selling derivatives, you'll go broke not doing that bookreading stuff regardless of whether you're in agriculture, futures or building. There's always someone who's willing to work harder than you so to succeed you need to be a bit smart. There's also a lot of luck, but to an extent you make your own luck sometime through that bookreading stuff. I've attached a graph of the oil price over the last 2 years, it seem to fluctuate quite a bit, also the wheat prices over a longer period, I've also included the price of oats because I thought it might be of interest to you. Things like that make business hard. If you read up a bit you might have noticed that America's oat districts were hit by a drought pushing the price up. Someone might also be able to pick up a pattern between La Nina and US drought impacting oat prices. I also run a business which has grown, possibly because I try not to do too many dumb things, like flying planes. However there are no guarantees as I always did have a natural talent in that area so take anything I say with a grain of salt 😉

Your conflating unrelated issues, farmer grow crops for money. If there's more money in fuel they'll grow fuel. Agricultural goods have been driven to very low prices historically and may rise. This is a good thing for agricultural producers and exporters and may lead to people not feeding grain to cattle. Currently about 36% of grain production goes to animal feed with only 55% used as human food. If you suspect it do some research using government sites, your suspicions are just plain wrong and yes they account for all the things you mention. The term that you're looking for is Net Energy Balance or NEB, here's a link Canola crops aren't irrigated, have low use of pesticides and don't always need them. Yes palm oil plantations have been very environmentally unsound however that's just one third world data point. Another data point is that famines don't occur in countries with a free press so if you're concerned about people not starving make sure that countries have independent media rather than worrying about hypothetical fuel food congestion.

Where do you get your "independent research" from? Facebook or independent researchers on the Internet? The science is absolutely blindingly clear and as a theory has been ascendant since the 1980s. When you look for factual advice look to scientific journals, even ones like new scientist or scientific american there is no debate, no lack of consensus and only the scientifically illiterate believe otherwise. The Murdock press has been consistently anti-scientific orthodoxy, giving every crank and their dog a forum from which to wax lyrical. The problem is not hydrocarbons it is simply the fossil ones, coal, oil and gas.

It requires some fuel, the returns are far greater, it requires about 40-55L fuel per hectare to crop canola. The yield is 400-900L per hectare. On a 2000 hectare property that's quite a bit of oil. I'm not saying that other processes can't produce liquid fuels with net zero emissions however the agriculture route is a well understood one. Nobody will force farmers to grow crops at a loss, they'll only do it if it makes them money. There are also lot of people betting on ammonia as a fuel created from cheap solar and wind, that sounds an awful lot like the Haber process for fixing nitrogen so you have a lot of fertilizer being produced without fossil fuels. The key point being that fossil fuels are used in the process at the moment because they're convenient, the process also works without them.

The emissions reduction index from the United States National Biodiesel Board showed that the combustion of biodiesel wholly as a transportation fuel decreased total hydrocarbons, polycyclic aromatic hydrocarbons, carbon, and sulfur emissions by 67%, 80%, 48%, and 100%, respectively. There's a slight increase in NOx however this is not across the board. NOx is just an equilibrium chemistry reaction, the hotter and hence more efficient your combustion process is the more NOx you produce. Cool the flame, inject water or add some exhaust gas and you force the reaction the other way. The other option is to remove it from the exhaust. In terms of lubrication biodiesel is a much better lubricant and makes your diesel engine last much longer. If fact it beat all of the aftermarket lubricants as fuel additive for ordinary diesel for lubricating injectors. In terms of fuels competing with food crops that's an economic question which markets are good at dealing with. Basically coal and fossil fuels and cow farts are out and agriculture, solar and nuclear are in. Europe has some great resources for electrification which we don't have and France especially is madly exporting Nuclear generated power generating 3B Euro per year in exports. The key point isn't electric vehicles and banning ICE it's zero emissions, hydrids can be zero emissions if they burn a zero emission fuel, it's not cheating. While this is the sane choice which anyone with a basic understanding of maths and science should be able to comprehend, when you are running towards a cliff, simply slowing to a walk doesn't solve the problem, stopping solves the problem. Economically we're going to face very large tariffs if we don't go down this path so pragmatically we need to change our approach. The wealthy countries which buy our stuff are watching our emissions and will tax the buggery out of us if we don't comply. Poor countries which don't have these policies don't have the budget to buy our goods so telling the rich clients to bugger off will be expensive. So even if you want to say "I don't believe that sciency stuff" you're community is going to face a huge hit to the hip pocket by taking a contrary view. It's a bit like being a christian butcher in a primarily jewish and moslem community, the meat that you sell will be kosher and halal but do you believe in any of that hockey pockey? No, but you make a pragmatic business choice. Anyway planes will require liquid fuels for the foreseeable future so what is the zero carbon emission fuel of choice and what will your baby run on? Lycomings will run on ethanol however storing it in Fibreglass tanks is a bit problematic 🙂

On the fuel note, does anyone know if an experimental diesel powered airplane has flown in Australia? I think that someone in Tasmania was looking to put a Subaru diesel in a plane and I'd be interested to know how far they've got or did it all become too hard. I think that the biodiesel route is probably simpler and cheaper than the other fuel pathways in the longer term.

I'm happy to take a bet on this fantasy if you wish. In Norway 80% of vehicles are now electric, in Europe 20% of sales are now electric, Australia's stance is an outlier however we're being dragged into a carbon market. Now I own a petrol burning vehicle however I accept that at some point fossil fuels are going to be taxed like buggery and the tax breaks for electric will be pretty compelling, either that or biofuels.

The pain is necessary, to believe otherwise is naive and change needs to occur on all fronts. Unless you're completely withered you're going to see a massive change in your lifetime, which will probably lead to significant conflict and human misery. Our own bushfires have just been the beginning, the barrier reefs will be a tragedy and mass ocean extinctions due to acidity combined with warming. However the key message is carbon neutral not the death of ICE, I would guess that for cars battery powered electric will end up being the cheaper option. However all this is off the topic of airplanes. In short people will not want to give up international travel and air freight so jet fuel in one form or another will remain. There are choices however if I was looking to build a plane diesel engines would be high on the list simply because they're more efficient and can burn jet-fuel.

The changes will take a long time if the change is dependent upon building new infrastructure. For example in the graph above look at the adoption time of change that required infrastructure with end to end connectivity. Cars required better roads and fuel distribution mechanisms, electricity required distribution networks and power generation stations. For example if you had a hydrogen refueling station, how do you get hydrogen to that station? Do you liquefy it, build a pipeline or manufacture it onsite from the electricity grid. Because where you make it isn't where people want to use it. In a side by side comparison hydrogen costs up to 14x the cost of direct electrification. Now I know that these figures are rubbery however it looks like lithium batteries have already won the vehicle transport battle because the infrastructure for charging partially exists. Who's going to build a network of hydrogen stations for an unproven part of the market, especially when the range of a hydrogen car is less than a battery powered one. Now I've been a fan of fuel cells for a long time, however hydrogen as a fuel a bit of a turd, there is an alternate methanol economy which hasn't had much attention however direct methanol fuel cells currently require platinum so a breakthrough is needed. I suspect that the reason that hydrogen is being pushed is that the gas companies believe that they can produce hydrogen from fossil fuels maintaining the value of their assets as part of the gas led recovery. Weaning off fossil fuels will be very very hard. According to the Bill Gates book "How to avoid a climate change disaster" only 12% of fossil fuels are used intransport the rest are consumed making thing and heating and cooling etc. And yet we're finding the first 12% really difficult, think how we're going to do without concrete, steel, plastic and fertilizer. Even aluminium manufacture uses carbon anodes and cathodes which are consumed releasing CO2. So the one structural thing that we refine electrolyticly still produces CO2. Just look at concrete and you'll figure out how hard things will be. Anyway as I said either batteries need to get a lot better and cheaper or we need Nuclear.

While I see people mention hydrogen it's a difficult fuel compared anything liquid, I've even see people speak glowing about converting hydrogen to ammonia and suspect that they haven't read the history of ammonia safety in refrigeration. Hydrogen is high in volume and interacts with most structural metals to cause hydrogen embrittlement. In comparison ethanol is simple, there are already planes flying however it does impact your range. There's a large body of knowledge relating to making combustion engines run using it. Butanol has a similar energy content and octane rating compared to avgas and can be produced in a carbon neutral manner. Biodiesel and related process can produce jetfuel analogues which have already been demonstrated to work in turbine engines. Yes there are issues associated with things like low temperature stability but they're pretty simple to solve. As policies change to force transport to be carbon neutral things will change however there are some pretty simple solutions out there. The solution will have a significant agricultural component so I can see this benefiting countries like Australia enormously. There is a huge issue will intermittency associated with solar and wind which remains an unsolved problem. A huge amount of power intensive industry is only economic when it runs 24x7, these industries won't function with intermittent power. Storage is expensive and countries like Australia which are flat and dry have very limited hydro options. Long distance power option such as high voltage DC are expensive, about a billion dollars to supply the UK from France. Frankly I don't see anything but nuclear as being able to fill the gap in the near term.

I'll bet you 20L of diesel that you're a bit picky 😉 Though I would love a piston engine that could burn jetfuel or diesel.

One thing that I've found, especially if there's a disparity in experience between the team member is that sometimes people don't speak up when they think something is wrong/incorrect. It's a real issue for some people and cultures. Doubly so when you're flying, so in that situation always brief people, if something appears wrong or dumb speak up.

My understand is that a diluter/demand system with a mask can also be used be in unpressurized aircraft to 40,000 feet and that this doesn't require a pressurisation endorsement if your plane can fly that high. However just because it's so doesn't make it safe and risk free. There's also a good report here in relation hypoxia in flight https://www.atsb.gov.au/publications/investigation_reports/1999/aair/aair199902928/tab-abstract/ From the attached CASA document. Demand regulator: This type can be further divided into pressure demand and diluter demand type regulators. Diluter-demand and pressure-demand masks supply oxygen only when the user inhales: o Diluter-demand system: as the altitude increases, ambient pressure (and therefore the partial pressure of ambient oxygen) decreases, the oxygen flow increases such that the partial pressure of oxygen is roughly constant. Diluter-demand oxygen systems can be used up to 40,000 ft. o Pressure-demand system: the oxygen in the mask is above ambient pressure, permitting breathing above 40,000 ft but as the pressure inside the mask is greater than the pressure around the user’s torso, inhalation is easy, but exhalation requires more effort. Out of curiosity, does anyone know where the baro chambers are in Australia and how much it is to do a stint in one. It might be a good birthday gift for some pilots, especially if there's video footage. DESIGN-AND-FITTING-OF-OXYGEN-SYSTEM.PDF

All Good, it's a fair cop, the whole COVID thing is a great example of how people can grab the wrong end of the stick and refuse to believe anything that doesn't align with their point of view. I'm happy (relatively speaking) to change my mind and eat crow should the weight of evidence suggest I should do so. If there's evidence that vaccines start turning people into zombies or similar I'll reconsider my stance, but in the meantime I won't taking medical advice from Trump or Bozo on facebook. Universities, Government research organisations, and Journals tend to be good places to get information. The thing that really makes me laugh about people with conspiracy theories involving Government is that somehow they think that the same management practices which make CASA could have some overarching secretive agenda which they've coordinated across decades; think about it. Personally I'm pleasantly surprised if a Government building has toilet paper. I once worked on a project where one of my peers argued strongly for a significant change to a design against which I argued pretty strongly, however that evening I decided that yes he was right and spent the night changing a presentation to reflect his critique. The next day during the presentation I let people know that it was his design and tried to handball part of the presentation to him however he didn't say a word. Afterwards I asked him why and he said he was just shocked that I had changed my mind as I argued against it previously.

Hi All, I saw this article in the Kitplanes magazine and wondered if anyone in the community used oxygen on a regular basis and had put together their own kit or purchased a complete assembly. How much and how accessible were refills and did it sit unused or was it a considered piece of safety equipment which provided you with additional options. What size cylinders provide the most utility? I also saw this article written about the use of pressure demand systems however I can't quite see that use case in the near future. I do like the approach, qualifications and experience of the author though.

I've seen opinions and stories of black gum and varnish without a skerric of a picture or other evidence but the mention of someone thinking that they read something get's a reaction. FFS 🙂 That made me laugh but anyway I didn't think that what was written here was gospel and people had a bit of a clue how to use google, so for those with the interest here's a link with the claim and another one All in the pursuit of better practices I suppose 😉 For those who like to read, there's also a good article on Ethanol and Octane rating. How-Does-One-Measure-Ethanol-002.pdf