DH4
DH4 is the abbreviation for:
- De Lackner DH-4 Heli-Vector , see De Lackner HZ-1
- the De Havilland DHC-8-400 turboprop aircraft , see De Havilland DHC-8-400
- the single-engine, two-seater double-decker Airco DH4
- DH4 (RAJA) , a series of diesel multiple units of the RAJA passenger transport company of the Railway Company of the Islamic Republic of Iran