[Majestic121]

While I think the project is pretty cool, I can't shake the pollution side of things out of my mind.

Air transport is one of the most polluting ways to travel, and I would expect a single person airplane is even worse than a full A380.

Is there anything you're doing to alleviate this issue ?

[n_ermosh]

Our early model you see here will use unleaded fuel rather than traditional low-lead fuel used in aviation today. The master plan is to use the scale we will create in this new market and invest it into green propulsion tech for our future aircraft. A lot is going to change in that space over the next 5 years so I'm very interested to see where things go, but I suspect hybrid-electric will be the move for the first generation of green aircraft.

[aziaziazi]

> green propulsion tech

Fact of the lead content, the wishes and the promises of your post have a place here.

However "Green" only sounds good in a marketing pitches. While it might resonate with potential customers who are already sold on the idea, it can come across as vague and insubstantial to those trying to understand your response.

It sounds misleading and deceptive for the individuals who are skeptical of the environmental impact.

[n_ermosh]

fair criticism--I should be more specific than just "green".

our first model will still be a gasoline ICE airplane, but we are building a limited number of them to get our tech out there and get a new wave of people excited about GA. out future aircraft will be able to utilize our fly-by-wire/simplified controls to fly more aerodynamically efficient airframes that will use less energy, whatever that source is. We can do this because these airframes would be too unstable for a human to fly by hand, hence the need for fly-by-wire/simplified controls in the loop.

today, we don't have a good alternative to ICE for airplanes that also meets the mission profile of the vehicle. I personally think hybrid electric is at least the next step, with hydrogen (though that has it's own challenges) coming after.

[Aachen]

How does further reducing lead in the fuel compare to all the other emissions' impact?

I would imagine that lead is dangerous for a long as it's being used, whereas CO2 has an annoyingly long half life that we need to actively remove in (currently) time- or energy-intensive processes, while it's reducing healthy years of life for millions of people —speaking of air pollution from combustion in general here, I don't have specific numbers for airplanes but as an airplane company you are surely better aware of this than me

[_jss]

Take a look at the more economical modern GA aircraft. A Cirrus SR22 can run at 10 gallons per hour, with a ground speed of 160+ mph.

Yes, it’s more total fuel consumption than a car (but in an hour covering 2x the distance, and allowing to travel more directly) but not at all close to turbine or turboprops. At the extremely cheap (accessible to more pilots) side for pressurized planes, fuel burn is going to be 40gph and it just goes up from there.

There are many variables, and winds work for or against—but by doing good flight planning you use the winds to your advantage.

There is also a lot of research on better aviation fuels (100ll :(((). I’m excited about that part of it, more so than the current electric planes (although electric self-launching gliders are pretty neat)

MOSIAC is going to make light sport aircraft more useful, which will also help in this area.

Tons of interesting stuff happening here!

[limitedfrom]

You can argue for its convenience/speed/fun, but fuel efficiency does not look good for GA aircraft. Even for your modern GA aircraft example, it literally comes to 16 mpg. This is as bad as worst of the trucks out there. While it's great if existing use cases of GA aircrafts would become more efficient, adding demand in this area (more hobbyists, more rich people shuttling use, encouraging people to live in very remote areas, etc.) and using it as transportation-mode will unlikely ever become environmentally reasonable.

[_jss]

All that is true, but it’s also getting better. And 16mpg over shorter routes (a 100nm flight vs 200 mile drive is not unusual) makes it harder to compare apples to oranges.

We don’t really have hybrid planes yet, which will likely help in the most inefficient parts of flying (climb).

My comment is to add more information to the discussion to consider many aspects, not to make claims that it’s a fuel-sensible method of travel. I am excited for innovation here, just like I am excited for the continued improvements in hybrid and electric cars.

[n_ermosh]

yep! lots of interesting stuff indeed!

Our plane will be ~7 gph at cruise burning unleaded fuels and fly ~170mph over the ground (with no wind)

[entropie]

For my part, I find it questionable to invest in and develop a transport technology that consumes seven times as much fossil fuel as a car.

You give consumption of 7 gallons in cruise mode. I don't want to know what is burnt during take-off or landing.

[lutorm]

How do you get seven times?

Takeoff constitutes a negligible part of the total fuel consumption. Climb to altitude uses more, but you get that back when landing since you're then using your stored potential energy.

Small-aircraft GA is a vanishingly small fraction of total fossil fuel use, and it will be quite easy to replace that with some renewable fuel solution (compared with the huge amounts of fuel consumed by transport aircraft). For my part, I think it would be a shame to kill GA because of a temporary and relatively unimportant concern.

[Aachen]

> Small-aircraft GA is a vanishingly small fraction of total fossil fuel use

OP wrote: "We want people who don’t think about airplanes as a mode of transportation to start flying"

They're meaning for this to become a larger fraction, besides that the relevant measure is pollution per benefit or per capita or something rather than absolute amount of pollution

[lutorm]

So you're concluding that there is no benefit to general aviation because, presumably, you don't fly?

I think we should absolutely keep airplanes as a mode of transportation, because the alternative is that all small airports go away and then it won't matter when renewable fuels become a reality because there will be no longer be anywhere to land and take off. Those airports would not come back.

[entropie]

> How do you get seven times?

I asked chatgpt what the average consumption of a car is; the answer was 0.5-1 gallon on a highway.

[FabHK]

Don't confuse gallons per hour with gallons per mile.

[callalex]

That’s only 25 mpg which is widely considered to be unacceptably unsustainable even in the short term.

[pbronez]

A Quick Look at FuelEconomy.gov shows many modern cars for sale with highway efficiency of 25mpg or less. Some (many?) people may judge it unconscionable, but it’s clearly acceptable to the broader market and current regulations.

These models seem to be big (Volkswagen Atlas, Subaru Ascent, Ford F150) or fast (Audi RS5, Porche 911, Kia Stinger). If you can get similar mpg from an airplane that carries four people and their luggage at 100+ mph ground speed on a more direct (shorter) route… that’s very compelling to me.

https://www.fueleconomy.gov/feg/PowerSearch.do?action=noform...

[FabHK]

So, reducing car emissions by a just 1% would be way better for the environment than entirely removing all piston engine aviation.

There are about 15m cars sold in the US every year, but around 1500 piston engine planes. That's a factor of 10,000. There are some 210m cars in use in the USA, but around 150k piston engine planes. That's a factor of 1400 (reflecting the fact that planes have a much longer life than cars, further contributing to their lower environmental impact).

Every day, cars burn more fuel than light airplanes burn in a year.

This project is a minuscule rounding error in climate change drivers.

[BWStearns]

Some of the LSAs I've flown are not actually that bad pollution/climate wise. Slightly less green per mile than my mini cooper, way more green than basically any common American pickup truck.

[blt]

MPG-wise sure. Emissions-wise almost certainly not. Airplanes don't have catalytic converters, exhaust recirculation, etc.

[callalex]

Does this include the emissions portal-to-portal? Airports tend to be nowhere near destinations because people don’t like living near all the pollution airplanes spew.

[BWStearns]

Most of my trips in small planes are pretty point to point. The airports I've used have been between 1 and 5 miles from my house and most of my destinations were similarly close (I just checked one destination and it was 200 meters).

Not sure where you're from but airport density in the US is incredibly high thanks to WWII and Cold War leftover infrastructure (and a fairly robust GA culture up through the 80s). People just don't notice their little local airports unless they fly.

[limitedfrom]

Avgas (most commonly 100LL) continues to spew out lead, which was phased out for cars in 1996 in the US, is a major pollutant.

[1] https://www.epa.gov/newsreleases/epa-determines-lead-emissio... [2] https://www.nbcnews.com/business/business-news/leaded-gas-wa...