The EA-400 is a pressurized airplane for travelling, featuring carbon fiber construction, a cantilevered high wing, and a water-cooled Teledyne Continental TSIOL-550C engine.

The aircraft's Fowler flaps feature a completely recessed mechanism and reduce stall speed from 76 to 58 kn (141 to 107 km/h) at maximum weight.

The deicing equipment is powered by a pair of large alternators (100 and 85 amps) that also feed the AC compressor located in the tail.

STCs for upgrades to modern GPS navigators and "glass cockpit" displays are available, but the only autopilot certified is the STEC 55X.

The Extra 400 was costly to manufacture, requiring 16'000 hours of labor, and carried a price tag of $1 million.