The creation of the Caribou moved de Havilland Canada into the big
leagues of twin-engine design, and marked the company's coming of age. Although the
program nearly bankrupted the company, the Caribou set de Havilland on the path to its
present status.
Attempting to cash in on the military market that they had previously "captured by accident", they set about designing the "ultimate" Army plane, which was, by their own description; a three-ton tactical transport with rear loading. Using these as tentative specs, the Caribou program began in 1957.
The army wanted them ready to fly almost immediately. The urgency of delivery obliged de Havilland workers to develop new testing techniques, a complete design, and a prototype within 7 months.
Trouble began with certification and political arguments in the states against the US Army buying more Canadian-built planes. De Havilland was struggling to meet FAA requirements and with only five orders for the DHC-4 on the books money was getting tight. Once all the wrinkles were ironed out, the U.S. (although enthusiastic) did not order more Caribous.
De Havilland Canada was nearing bankruptcy. Finally, after demonstrations on the Caribou's STOL capabilities, the Army committed to buying 165 planes. Soon after, India, Australia and Malaysia signed on, and the Caribou was a success.
Currently, old Caribous are being repurchased by Canadian operators, and being used as bush-cargo planes.