> What is the purpose of the second person in such plane, at the air show?
Pilot Flying, Pilot Monitoring (and dealing with radio and coordination).
It's hard to see single-pilot operations outside of General Aviation aka people flying for fun or for dusting crops - and enough incidents happen in GA, especially in cropdusting, that it might make sense to mandate two-pilot operations there, but good luck trying to get that passed, people are already complaining as it is that aviation is too expensive and in fact are moving towards getting commercial aviation to single-pilot operations.
As I understand it "dusting crops" is commercial aerial work and thus outside of
General aviation (GA) is defined by the International Civil Aviation Organization (ICAO) as all civil aviation aircraft operations except for commercial air transport or aerial work, which is defined as specialized aviation services for other purposes
Crop dusting, small frame fire suppression, and small frame geophysical surveying are often single pilot- and geophys surveys can drape entire countries at 80m ground clearance and 200m line spacing (plus transverse lines) so they can really rack up the hours and line kilometres.
Uh, that's not correct. The back-seat in the Growler is an Electronics Warfare Officer. He may be monitoring the radio, but he's not just a second pilot (as is the case with commercial passenger aviation); it's a completely distinct job with a distinct training program.
And of course, most modern fighter jets are actually single seat. And they operate just fine that way.