Actually, you might want to think a bit harder about that. Any publicly funded research that NASA does is available to the public. That means Airbus can use it too. If there is a specific task done for a manufacturer, US or otherwise - say wind tunnel experiments on a particular design - the company pays for the use of the tunnel. When NASA flew tests on an MD-11 to see if it could be controlled and landed by engine power alone (it could) that was published for all to use, not just US companies. So, no NASA is not a US subsidy.