The Bellanca 31-40 Senior Pacemaker and its derivatives were a family of a six- and eight-seat utility aircraft built in the United States in the late 1930s.
The model numbers used by Bellanca in this period reflected the wing area (in this case, 310 square feet) and engine horsepower (400 and up in this series), each divided by ten.
A single Senior Skyrocket was bought by the United States Navy in 1938 for use as a utility transport, designated JE-1.
Senior Skyrockets were also built under licence by Northwest Industries in Canada following World War II.
In 2007, a single example remains extant - the first Canadian-built aircraft (registration CF-DCH).