Of course. Unless President Trump is going to make Mexico pay for everything and "take the oil" from ISIS.
It was a somewhat humorous suggestion, but IMO deserves serious policy consideration.
Air travel should, IMO, be viewed at least partially as public infrastructure like highways, rail, ports, electric grids, sewage systems, etc.
If we left these things to the private sector, the scale of risk would be so great that sub-optimal investment would occur even were private firms able to overcome the collective action and bargaining problems inherent in, e.g., building a highway.
Arguably we have too little total investment in aircraft development right now:
-Boeing projects $5,570bn worth of airplane deliveries through 2034.
-Airliner acquisition costs are ~25% of the airline industry, so we're talking over $20 trillion in economic activity through 2034.
-Reducing airline unit costs by 5% would save $1,000bn dollars and would stimulate additional travel and economic activity
-The scale of airliner efficiency's global benefits far outweighs even $50bn in a generation's development costs.
The problem, however, is that (1) capturing more than a sliver of these benefits is difficult for the OEM, and (2) individual private investments in airliner development are tremendously risky and hard to diversify, despite the long-run returns across society being great.
A truly long-term, economy-changing product might be best financed by the most risk-hungry investor with the longest time horizon: the public fisc. Even if that investor makes less efficient decisions than private investors (the government surely does), the increase in overall level of investment may be socially optimal and economically efficient.