Boeing 221

The Boeing 221 Monomail was the passenger version of the Model 200 Monomail mailplane. The aircraft marked a departure from the traditional biplane configuration for a transport aircraft, instead featuring a single, low set, all metal cantilevered wing. Retractable landing gear and a streamlined fuselage added to the aerodynamic efficiency of the aircraft. The Model 221 carried 6 passengers in an enclosed cabin, however the single pilot was in an open cockpit. Both the Model 200 and the Model 221 were modified for transcontinental service as the Model 221A. The advanced design of the Monomail was hampered by the lack of suitable engine and propeller technology. By the time variable pitch propellers andf more powerful engines were available, the design had been surpassed by multi engined aircraft, including Boeing's own 247.

General characteristics

• Crew: 1
• Capacity: 6
• Length: 59ft 1in ()
• Wingspan: 41ft 10in ()
• Height: ()
• Max takeoff weight: 8000lb ()
• Powerplant: 1× Pratt & Whitney Hornet B , 575hp ()

Performance

• Maximum speed: 158mph
• Cruise speed: 135mph ()
• Range: 575mi ()
• Service ceiling: 14,700ft ()

Boeing 221 Monomail
Type	Airliner
Manufacturer	Boeing
Maiden flight	1930-05-06