CHICAGO (Reuters) – Beware of spilling drinks while flying a plane. During a United Airlines flight to Frankfurt, Germany from Chicago this week, a cockpit crew member spilled a beverage on equipment, an airline spokesman said. It prompted a chain of events that inadvertently sent an alert that the plane was being hijacked. "During a period of light turbulence, a cockpit crew member's beverage spilled, causing issues with the airplane's communications equipment," said United spokesman Rahsaan Johnson. The beverage caused a problem with one of the aircraft's radio systems, which prompted the pilot to decide to land the plane Monday...