Anything in a regulated industry such as aerospace tends towards the process heavy. Our requirements get tracked in our QMS system that ensures we're AS9100-compliant. There's a final test-for-credit step after which the software part should be considered hermetically sealed. Any software change requires a new test-for-credit round that likely takes an extensive amount of time.
So, in short, developing for aerospace is not agile. :-) It's the Niagara Falls of waterfall methods.
I work at BAE and we do quite a bit of software for Boeing. DO178 C could allow you to do Agile if the PSAC was set up from the beginning for that. The problem would be the cost points and contracts and customer buy in that would be needed on all sides. But alas for now it is the mother of all Waterfall methods.
So, in short, developing for aerospace is not agile. :-) It's the Niagara Falls of waterfall methods.