Their group departed from Volkel Country that same day, with the twins' group going ahead and leaving a thirty-minute gap before Aurundi followed. On the surface, that might not have seemed like much, but one had to keep in mind that Aurundi was there specifically to intervene if something went wrong. The sooner he could react to a dangerous situation, the better.
As for the Network Signal used by both airplanes, that could reach much farther than the distance covered during those thirty minutes. There was no real risk of Aurundi falling behind and eventually losing sight of the twins' group. Even if they accelerated considerably, their airplanes would remain within the range of his radar, allowing him to keep track of them without needing to constantly push himself to catch up.
Well... Rean's airplane was damn fast, but Rean would hold the airplane back to make sure Aurundi didn't really fall behind either.
