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Comment by Noseshine | Hacker News Reader

Question: Would that lead to some unfavorable chemical reactions that create undesirable molecules that we don't want to have in the atmosphere? It's an incredibly tiny effect per plane, but over time and given the amount of planes... so obviously only a problem for stable molecules that remain up there for a long time. I had the subject in a chemistry lecture, but it's been quite a while so I don't remember any details.

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Not really. Ozone is the primary byproduct of producing a plasma in our atmosphere, and it is really only a problem when it is released at lower altitudes. Releasing it in the upper atmosphere where jets usually cruise would be harmless, if not beneficial to the existing ozone layer.

Not to mention the fact that any byproduct produced by a plasma would be infinitesimal compared to the amount of NOx produced by jet engines.

The article mentions that plasma also produces a lot of nitrogen ions. Would this increase NOx production?

Probably. Oxygen and Nitrogen react quite a bit in the upper atmosphere where there is plenty of sunlight to initiate reactions. There is a litany of byproducts that can be produced, including NOx.

I suppose it could even out with the wins in fuel efficiency?

But UAVs don't fly that high. So they kinda have to poison the air for that 300% range increase

The ozone layer starts at around 65,000 feet, which is about twice as high as where jets usually cruise.

It would produce a lot of ozone probably, which is harmful to humans at ground level. But exactly what you want to put into the upper atmosphere as it protects from harmful radiation, see ozone hole.

Unfortunately it's not going to float up to the stratosphere from the troposphere, so a good portion of a flight will be causing ozone pollution.

I thought most commercial flights were above 20km, where the bulk of the ozone layer is? Edit: Oh you mean the takeoff and landing parts of the flight. Good point.

Commercial flights are at about 10 km.

I don't see this being much of an issue. Most aircraft kind of throw efficiency out the window while they are taking off/landing. You don't WANT overly aerodynamic wings at take off because you want exaggerated lift at the cost of drag. It wouldn't make sense to use the plasma until you are at a stage in the flight where you are more concerned about efficiency, i.e. cruising.

If they would succeed with "flapless" design it would be then different story.

I was wondering if this technology would help with reusable rockets. But what you've wrote and what I found about aerodynamics of rockets makes me think that it would not be that helpful.

[1] https://space.stackexchange.com/questions/744/effect-of-atmo...

My question was more about other compounds, for example those involving fluorine (https://en.wikipedia.org/wiki/Fluorine#Atmosphere). I have not asked about F specifically because that is known and in decline (I think), but there may be other things in the air that specialists know better.

GA still runs on leaded avgas

Gross. Let's fix that first.

Shipping runs on oil sludge - the vilest, most polluting substance used anywhere. 6000 cargo ships produce more air pollution than half the rest of the world. So when prioritizing things to fix...

Already happening. Jet-A is more widely available and cheaper. Take a look at all the new diesel engines coming to market.

But isn't price still an issue with those new aircraft?

I've thought many times about trying to get my pilots license but have always been dissuaded by the thought that the only general aviation plane I can imagine being able to afford would be from the 1970's or earlier. If they're well maintained they seem to last forever. What's the incentive to spend many times more money for aircraft with those newer, cleaner engines, especially for beginning pilots? Would something like a "cash for clunkers" program for airplanes be feasible?

On your own? You're probably right; planes are expensive.

Have you looked into nearby aviation clubs, though? I mean, it's still expensive, but a time-shared plane is far less so than a personal one.

I bought into a very well maintained grumman tiger, which with a sliding canopy is still damn awesome compared to "modern" planes (most certified designs you can buy date back to the 60's, with the exception of cirrus who is now unsurprisingly selling the most new planes).

17k for my third.

Already in progress. FAA is working with industry to come up with an unleaded aviation gasoline that will be "drop-in" compatible and replace 100LL.

See https://www.faa.gov/about/initiatives/avgas/

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