After the initial evaluation of the Lockheed Model 12, the Air Corps ordered ten additional production Electra Juniors in the fall of 1938. The planes were delivered in the first quarter of 1939 and were designated C-40A.
The C-40A was externally identical to the C-40, but featured a hybrid passenger/cargo interior. In the original configuration, the C-40A carried a crew of two, up to three passengers and a light cargo load of about 1,000 pounds maximum. The gross weight of the C-40A was about 400 pounds higher than the C-40 and was slightly faster also. During operational service, the C-40A interior was often configured in the field depending on the specific mission. In most respects, the C-40 and C-40As were indistinguishable from each other.
During 1939 and early 1940s, most C-40As were assigned directly to operational groups and squadrons for use in support, liaison, transport and light cargo carrying missions. These "squadron hacks" were replaced by newer aircraft in the mid-World War II era. Most C-40As were declared surplus by mid-1943 and many were sold to foreign air forces.
Model 12 Electra Junior
Tricycle landing gear testbed
Designation not used
Impressed Electra Juniors
TECHNICAL NOTES: Engines: Two Pratt & Whitney R-985-17 radials of 450 hp each Maximum speed: 220 mph Cruising speed: 210 mph Range: 800 miles Service ceiling: 22,900 ft. Span: 49 ft. 6 in. Length: 36 ft. 4 in. Height: 9 ft. 9 in. Weight: 9,600 lbs. maximum gross weight Crew: Two (pilot and co-pilot) Passenger capacity: Three Serial numbers: C-40: 38-536 to 38-538; C-40A: 38-539 to 38-548; C-40B: 38-582; UC-40D: 42-22249, 42-38280, 42-38346 to 42-38352, 42-57504, 42-66386