[thinkling]

The point is that you're building a vehicle that (I assume) will produce far more pollution (CO2 and otherwise) per passenger mile than existing aircraft. Is that an ethical thing to do at this point in time?

[runarberg]

This is a good question to ask. The answer is obviously “no,” but it would be interesting to see an ethical argument for designing this.

[monort]

Is it ethical to raise consumption with a raise of your salary? Is it ethical to give the raise to these employees?

It looks like the answer should be the same to this and your question.