Boeing Engineer Flags Safety Concerns Over 787 Dreamliner Structural Integrity

• Boeing engineer alleges 787 Dreamliner planes have structural failings that could cause them to break apart

• Claims 787 fuselage parts are improperly fastened together and could separate after thousands of flights

• Allegations come as Boeing faces crisis - CEO stepping down after safety issues with 737 Max planes

• Engineer had previously sent concerns to Senate committee investigating Boeing's safety culture

• Boeing disputes allegations, says testing shows 787 can operate safely before needing maintenance