The Federal Aviation Administration is investigating after a Southwest Airlines flight reportedly plunged to “within 400ft” of the Pacific Ocean during a flight.A memo distributed to Southwest pilots, obtained by Bloomberg, said that the Boeing 737 Max 8 plunged at a rate of 4,000ft a minute off the coast of Hawaii, coming within hundreds of feet of the ocean before climbing to safety.News of the incident comes as investigators said a Southwest-operated Boeing 737 Max 8 sustained significant damage after it ...