The Failover File by Alan Haggerty

Mike O'Hara is an ex-Navy officer, ex-astronaut and serial ex-boyfriend. He is also an engineer and a crash investigator for the NTSB. When a private jet owned by global mega-corporation ZYCO mysteriously crashes, Mike and his team find hacked software in the plane's control computers. Mike and computer expert Sally Montez race to track down the hackers before they can strike again. They are thrown into a world of extreme wealth, international financial intrigue and corporate espionage, and as they close in on the killer, the hacker strikes again. ZYCO's founder, celebrity billionaire-genius Eric Zygler, joins the effort to help find the hacker, but as the case comes together Mike realizes that the evidence points to Zygler. Mike must trap and force a confession out of the murderer or lose his career--and maybe his life.