Bad news: Four hours x 500kts = very large AOU.

Good news: The engine data should provide insight into whether someone was actually flying the airplane.

But I'd be curious to know exactly how engine data is transmitted to Boeing...that would clarify what systems might have been damaged vs. intentionally disabled. It seems a stretch that a failure/fire could have disabled comms/transponders but somehow the engines are still able to phone home. Unless they have their own data system with SAT link? That would seem like overkill.

Anybody know?