The upper component, Mercury, was a twin-float, four-engine seaplane crewed by a single pilot and a navigator, who sat in tandem in an enclosed cockpit. It could carry  of mail and  of fuel.
The upper component, Mercury, was a twin-float, four-engine seaplane crewed by a single pilot and navigator who occupied an enclosed cockpit. It could carry  pounds of cargo and  gallons of liquid fuel.