B-21 (Spartan Sp-21M) Land Based Torpedo Bomber
10 in service
Dimensions: span 20.42m; length 12.19; height 3.84m; wing area 600sq ft; wing loading 31.33 lb/sq ft; power loading 0.234kg/hp 0.10 lb/hp
Structure: all-metal monocoque fuselage in four sections with Z section fames and L section stringers with light alloy covering, light alloy used for tail construction and cantilever tailplane covering. Cantilever all-metal wing with two steel spars, all-metal split flaps and aluminium framed ailerons with fabric covering. Rudder and elevators aluminium framed with fabric covering. Retractable hydraulically raised main undercarriage with two oleo-pneumatic legs with twin pneumatic brakes and a non-retractable castoring tail wheel
Weights: empty 11,670lbs, maximum take-off 18,800lbs
Powerplant: two 1000hp Spartan 1000 supercharged radial engines
Performance: max speed 267mph; service ceiling 26,500ft; rate of climb 1,094ft per minute at 1,500ft; range 1200 miles with 3,000lbs bomb load
Capacity: pilot in enclosed cockpit with bullet-proof windscreen, navigator in rear fuselage cabin with one window and one access door ahead of radio operator/gunner in a hydraulic-powered dorsal turret
Armament: one dorsal turret with two 7.92mm FMG/M32 MG (drum feed), four fixed 13mm Browning HMG in the lower nose under the cockpit, bombload 3000lbs in one lower fuselage bomb bay or one semi-recessed 18-21in torpedo
Equipment: full controls and navigation equipment including receiver/transmitter, HF/DF set, naval co-operation beacon and Sperry autopilot, two cameras can be fitted in cabin floor, one flare chute, two rescue dinghies and mechanical bombsight