The fuselage was constructed of welded chrome-moly steel tubing with aircraft fabric covering.

The wings used a unique double-layered corrugated aluminum skin with a smooth exterior that required custom presses to handle the various thicknesses of material along the span.

The NB-3 fuselage was widened, giving one cockpit a side-by-side seating arrangement to accommodate three people.

The Marshall Flying School advertised the NB-3 as a one-day-to-learn-to-fly aircraft with students flying in the morning, an aerodynamics class, learning how to weld by mid-afternoon, salesmanship, and a leisure round of boxing and swimming by evening.

[4][5] Ruth Alexander established a new world record for altitude in 1930 using an NB-3 over San Diego, California.