De Havilland DH.4 crash, Nov 30, 1921 (2 killed), Fort Si...
De Havilland DH.4 accident on November 30, 1921 near Fort Sill-Henry Post Field AFB Oklahoma, United States with 2 fatalities.
- Date: November 30, 1921
- Aircraft: De Havilland DH.4
- Location: Fort Sill-Henry Post Field AFB Oklahoma, United States
- Fatalities: 2
- Phase of flight: En route
De Havilland DH.4 trainers AS-63033 and AS-63604 collided in mid air during a local training mission at Fort Sill, Oklahoma, on 30 November 1921. All four crew members were killed.