Jonfliesgoats

Looks like Boeing has a modified Diamond flying on hydrogen power already.

When you think about it, scientific method itself is sort of misrepresented in the movies and television. There are many scenes in many movies with laboratories full of people faffing about with beakers full of smoking liquid, computers that beep unnecessarily, and malevolent supervisors. Few movies really describe testing of hypotheses, designing experiments, etc. One of the great wrongs done in the media is making science seem inaccessible to the masses.

I believe that is the last L-1011 flying, unless I am mistaken.

Regulatory issues for building replace,nets to reciprocating engines to install on existing airplanes are significant, but far from insurmountable. Aerodynamically, the kits could fit with very little modification into existing cowlings, even with existing engine mount geometry. Of course, my vision is nowhere near as ambitious as those pushing V/STOL capability. Existing airplanes with existing (fixed pitch) propellers etc. are in my mind. Using existing constant speed propellers becomes a little bit more challenging. These props use engine oil, so an oil-accumulator system would have to be supplied to existing high-pressure pumps and governors. Those governors themselves would have to interact with a new shaft system. None of these challenges are beyond simple engineering, but the costs of development and certification get s lot steeper. I am also taking cheap, reliable, hydrocarbon fuel-cells for granted. That tech. Is the real meat and potatoes (Beans and squash!! Yum!) of any sort of development in this vein. Also, good discussion on toxicity and chemistry in general, guys! Methanol is nasty and bad for rubber, but so is ethanol. This is why many auto fuel STCs (STC=supplemental type certificate) for light airplane are no good with oxygenated fuels (ethanol, mtbe), making the STC less useful. Ideally an fuel cell electric prop STC for existing planes would use materials that are durable for heavy and light fuels and resistant to polar, hydrocarbon solvents. Jets and turboprops, for example, can run on gasoline, kerosene based fuels, aviation fuel, etc. The engines themselves tolerate the variety in fuels well, but decreased maintenance intervals are required to monitor filters, pumps, etc. Replacing high octane reciprocating engines with fuel-cells would bring this versatility to smaller aircraft. In terms of toxicity, benzene, MTBE, tetraethyl lead and aromatics in general are pretty nasty. We need to consider health effects relative to other options in addition to health effects generally. Its safe to say that when hydrocarbon fuel cells become viable, my vision will be one of the least ambitious applications of the tech out there.

Great observations, Nibb! Actually, I was thinking about maritime law when I raised my previous question. In the North Sea, you have a single, large, political entity with friendly satellite states working in an uncontested sea in the presence of decently powerful navies which can exert rule of law. In the South China Sea or, better yet, the Straits of Malacca, we see continued piracy, murder, etc. The Chinese Coast Guard attacks foreign fishing boats in contested waters while other governments remove Chinese crews and destroy their vessels caught fishing in those same waters. Recently the Chinese towed a rig built by the Vietnamese out of position, so now a Vietnam is engaging in its own dredging and island building program. On a strategic level, the 9-dash line flaunts international maritime law, but the West will be hard-pressed to directly challenge Chinese claims despite interntantional court rulings against the 9-dash line. My point is that peace at sea only exists when there is little political contest for those waters and/or a single, powerful navy can enforce a particular set of laws. In space, as soon as something valuable enough to justify investment is proven viable, you see unclaimed objects and no space presence powerful enough to enforce rule of law. The stage is set for legal conflict and industrial or military shenanigans. The moon could become the next South China Sea if anything valuable enough was discovered there. Speaking of which, has anyonen figured the energy price point required to justify extracting helium 3?

Not a bad idea. We could call this a soft-destruction of the existing satellite.

I am kind of excited to see how these fuel cells develop.

This is cool, but it is a plane. Still, you can see the earth's curvature and appreciate things from a new perspective.

Communications, Reconnaissance and Navigation can't be underestimated, though. They are supremely valuable. Getting beyond those applications requires either mining or space borne combat. Look at the aviation advances made between 1914 and 1918. Do we need to start killing each other in space?

I know the OST doesn't prohibit mineral extraction, but what about security of such a large investment? If Rocket Inc. starts exploiting some resource, what stops Imperial Afterburner Ltd. from simply flying up and exploiting the same field of resources with a fraction of the investment? International Law is weak so, either we need national claims to blocks of celestial real estate, or we need an international governing body with teeth enough to enforce its laws. I suspect national claims are more likely than an international body that is respected and capable of enforcing law.

What do you think of withdrawing from the Outer Space Treaty? Without that, we could lay claim to celestial objects and the private sector could exploit them. The obvious cost is future weaponization of the moon, a prospect that isn't just for bad sci-fi, but something genuinely destabilizing in the medium and long term. Of course, conflict has driven advances since we first learned how to bash each other's heads in with rocks. Others would say that weaponization of space and claiming celestial objects is inevitable.

University of Wisconsin and Tom Jeffries, along with a host of others, work(ed) hard on getting ethanol yields up, especially from stuff with lignocellulose (woody stuff). I could imagine fuel cells with home-distilled ethanol suplying household power demands. For firewall-forward kits and existing airplanes, I would be happy with anything that uses existing hydrocarbons. There is growing concern with the use of tetraethyl lead in aviation fuel. Getting anything aside from jet fuel in most of Africa is a challenge. Overhauls costs for reciprocating engines run around 15-20 thousand dollars along with cylinders, etc. The price advantage of turboprops disappears below a certain power output. Developing this is a costly and time consuming process, but the economic incentives are there. This would be really useful for medium sized UAV/RPV too.

I think a good point has been made about quantitative easing and the ability of sham programs to sap some of that fresh, available capital. That said, I think we have the groundwork for a spaceflight boom. When we start seeing rapid reductions in launch cost driven by competition, it will be on. The next ten years will be interesting in that regard.

Yeah, and when you look at investments required for hydrogen infrastructure in the developing world, things start getting silly. I really like the methanol/ethanol idea for localized fuel distillation. The economics of how much biomass you need for a given energy demand aren't as unfavorable as people initially thought. There are articles out there, but fuel cell development hasn't made the news in a while.

This is an open-source story about the Turbocaribou https://warisboring.com/the-turbo-caribou-is-one-of-worlds-best-and-rarest-airlifters-64504bc767fc#.183su49ad

My antique airplane has a Continental C-85-12f motor which weights 180lbs along with another 60lbs of accessories and 20lbs of propeller. For now, let's exclude accessories and propellers. Anyway, figure 60kw for 90kg of engine. It's got to be easy for fuel-cell electric combinations to beat that. In terms of efficiency, the specific fuel economy of most reciprocating airplane engines is about .45lb/hp*hr or 280g/kw*hr. I don't have these numbers for emerging fuel cells. Also, this: https://www.technologyreview.com/s/426252/gasoline-fuel-cell-would-boost-electric-car-range/

Very cool! I think it would be conceivable to come up with firewall-forward kits to re-equip existing reciprocating airplanes with fuel-cell electric kits. The service life and overhaul costs would be much lower and the airplanes could use a wider variety of hydrocarbon or other fuels. I am having a little difficulty finding figures on weights and efficiencies of existing hydrocarbon fuel cells. http://newatlas.com/jet-fuel-electricity-room-temperature-fuel-cell/34594/ I am stuck on hydrocarbon fuel cells for now because it will be a while before hydrogen infrastucture is widely built out.

I was thinking about how propulsion in aerospace tends to become simpler and more efficient over time. We went from twelve cylinder, sleeve-valved reciprocating Rube Goldberg motors with short service lives to turbojets with, essentially, one moving part. Anyway, electric propellers seem to be en vogue for solar applications. What is the feasibility of using fuel cells and electric motors in the 200hp (150kw) range? Preliminary math to follow:

This is a good idea! Have you considered using flash animations? I know that becomes something of a challenge, especially if you have a real life. The benefit is that moving pictures and words keep people engaged and use different parts of their brains. More, different, brainy bits mean more better learning.

That's true. American planes aren't removed from the effects we describe. Americans seem obsessed with finding the most expensive and engineering intensive solution to simple problems, for example. Perhaps it is more accurate to think that the West tries to simplify with multi-role aircraft and develops engineering nightmares with huge max hour to flight hour ratios. Again, this is an artifact of political factors in the acquisition process. The West then cancels successful programs to support these things. Look at the CV-22 and F-35 for examples of doing less with more. It's easy to be a naysayer, however. From experience, getting something to the field with constantly changing requirements and oversight is challenging.

Great observations, all! This is a company with a proposal to launch cubesats from F-104s. I think they are associated with Starfighters Inc. They are the smallest scale air launch to orbit program I can find with Google. http://cubecab.com/

Very good question and observation! It was actually a holdover from a Stalin-era edict that wasn't removed from design bureau requirements until sometime in the 80s. Beurocracy being what it is, once a design requirement mad it out to the manufacturers, Soviet design bureaus were very, very slow to petition for changes to these requirements due to political considerations. As for rudder authority, it significantly reduced it from what could have been provided. Obviously, the remaining surface has been moved up and the hinge line moved forward to increase its area. Other devices can be used to increase rudder authority as well, like increased travel, servo tabs, etc. However, the aerodynamic efficiency of the rudder would have been significantly better without having a turret, especially a manned one back there. More rudder means more controllability with the loss of an engine, the ability to fly slower without compromising controllability with asymmetric thrust, etc. For a tactical airlift plane, trading low speed rudder authority for a turret that still does not protect you from air to air or surface to air threats is silly. Even if we say that available Soviet turboprop engine/propeller combinations didn't compromise the control authority of the plane, with existing empennage, the extra rudder authority allows for more engine options in future design iterations, greater single engine maneuverability and crosswind authority, etc. There are also limitations in load distribution and other practical considerations when control authority is limited. For their part some of the Russian decisions were really good. Their airplanes, the AN-12, 26 and 32 in particular, are all very sustainable in remote, commercial operations. This is a vestige of decisions to ensure the Soviet Air Force could operate from relatively austere airfields. The human stories in aerospace engineering decisions are pretty cool. Many WW2 British Bombers have fuselages that look like locomotives because they actually employed locomotive engineering, for example.

This is a dated article from the LA times discussing the uptick in private investment in space. Still it's pretty neat. Are the smartest people in finance predicting a new golden age of commercial spaceflight or are we in a 21st century version of tulip-mania? http://www.latimes.com/business/la-fi-qa-space-investment-20160707-snap-story.html

The Hump: success or failure? During World War Two, the United States engaged in a spectacularly costly airlift from India to supply Chengdu in China. We spent twelve gallons of fuel for every gallon delivered. Also, I use an example of military airlift because it has been widely studied and discussed. An Argument for Failure: Plans were made to increase bomber forces flying out of China to bomb the heartland of the Imperial Japanese Empire. This included plans to put our latest heavy bomber, the B-29 into fields in China. The economics behind the airlift were so abysmal that the island hopping campaign of the marines in the Pacific was strategically altered specifically to secure airfields for the B-29 that could be supplied more economically. What would we have achieved if those resources had not been wasted in China? In the years before the war, developing air power in the US created a group of senior officers that were in competition with each other to prove the value Air Corps. It certainly seems that mor attention was given to the airlift itself by some of these officers than the actual effort to achieve our national defense needs. The tired pilots and mechanics of the Hump may have set back the war effort, despite their best intentions. An Argument for Success: Nationalist Chinese forces were on the brink of defeat after five years of warfare with Imperial Japan. Despite the great cost of the airlift, enough materiel made it to the Kuomintang to keep Chiang Kai Shek's forces in the field and fighting. With the US surface fleet recovering from the losses of Pearl Harbor, seizing any Chinese port facility and holding it against Japanese retaliation would not have been feasible. An immediate need existed to keep the Kuomintang fighting and airlift filled that need. Without the airlift capability of the US, an extra million or so Japanese troops would have been free to fight in New Guinea or the Solomons. The tired pilots and mechanics flying the Hump saved China.

Good suggestions about timeframe with regard to airlift, guys. I tend to agree with those thoughts, but have a problem with them. This approach has been used many times in the past, but short term airlift nearly always turns into long term sustainment. Mission creep is a real problem! So perhaps the idea that airlift is a short term tool should be seen more as a goal than a doctrine? I propose that preventing mission creep in airlift requires a greater, strategic understanding of what an effort is trying to acheive. We also need to be realistic about people's motivations. Is there too much romance around humanitarian airlift and aviation? I think there may be. Also, more appreciation for the local diplomacy and management required to keep trucks or barges getting where they need to would be a good thing. There is no shortage of 20ish, young pilots who want to test themselves in the bush. I know how I felt about it at the time. I can't think of that many educated, 20ish young grad students who want to spend their time visiting with village elders and driving around to keep a road open and police officers functioning. Driving around in a dusty truck, to talk with people is more important than anything I used to do. Sadly, the folks in dusty trucks don't hold our imaginations like the guys in Twin Otters do. Can we make airlift more effective by educating the layperson about its failures?