Target the companies that work in the field?
For engines... pick any one of the 3 you like; Pratt & Whitney, GE or Rolls Royce.
For structural, aero, etc; Lockheed, Airbus, Bell, Leerjet, et al
Most of the competition has been squashed out of this field and know that, going in with the dream of starting a consultation firm? They all have long standing with various consultation firms across the country. That's not going to be an easy egg to crack... not to mention all the red tape that goes with anything pertaining to aircraft, which is only exacerbated in anything dubbed 'military'.
I hate to think that the days of the "Howard Hughes" are over but with governments being so intimately entwined with their 'aircraft' industry... they probably are.
Best bet is always (IMO), targeting the company(s) you want to work for... more so than hunting for openings you can take.