How Many Boeing 777X Prototypes Were Built?
For most of its 777X testing, Boeing has operated four prototypes. These aircraft are WH001 (N779XW), WH002 (N779XX), WH003 (N77XY) and WH004 (N779XZ). However, in August 2025, a fifth test aircraft entered testing: WH286 (N2007L). This aircraft is a production-standard Boeing 777-9. That means it lacks the complex flight-test instrumentationContinue Reading











