It used to be 77, which means 8x airs.
I know some friends (Lukietje and Mattiasbest), who are complaining about many F2P level 88 rc'ers, who 'steal' all air runners, because they can give 9x airs.
Members with 88 rc go assisting for double nats, but F2P'ers with 88 steal 77's customers, that's how it is...