The following information and story is conjecture (besides the official information of a CL-52 being used for testing) and unfortunately never served with the Canadian Forces.
In 1956 the Canadian Government had loaned a B-47B from the U.S.A.F. as a testbed for the Orenda Iroquois engine that was being developed by A.V. Roe Canada, Ltd.'s Gas Turbine Division (Orenda Engines).
The 30 foot long and 6 foot diameter engine pod was mounted on the right side of the aircraft below the tail plane. There were not many aircraft available that could handle an extra engine of the Iroquois' size and power. The modifications to the aircraft were done by Canadair in Montreal, and approximately 20 tons of instrumentation and ballast were added. The ballast was necessary to compensate for the engine's weight , as the B-47 was very sensitive to a shift in its center of gravity.
The Canadian flight crew which flew the B-47 received flight training at Strategic Air Command in the United States and were qualified as a regular SAC B-47 crew. This was a major concession by the United States Air Force on this highly classified aircraft.
51-2059 was delivered to Canadair for modifications, and then sent to Avro Canada. It was re-designated X059.
After Black Friday, and the taking over of Avro Canada by the Hawker-Siddeley Group, and being renamed Hawker-Siddeley Canada, the CL-52 sat on the back property until 1960 until being sent back to Canadair. By February of 1961, Canadair had returned the B-47 to the Air Force, but had made an offer on the jet after 3 months, and purchased the B-47 from the U.S.A.F. for $325,000.00 (a paltry price at that time for a state-of-the-art jet bomber), considering that the U.S.A.F. had scrapped the aircraft once it was returned.
The B-47 was flown back to Canadair and "the keys were turned over", becoming the only B-47 in ownership outside of the United States.
The aircraft was then again put on the back-lot at Canadair until 1962 before the engine nacelle was removed and most of the ballast and the rear of the plane was re-built (from the warping of the frame by the Iroquois engine test). The CL-52 was used by Canadair, as a systems testbed, and for advanced missiles that they were developing, and re-registered as CF-ACN-X.
By 1963, the R.C.A.F. had wanted to lease the CL-52 for evaluation purposes (considering the only evaluation the R.C.A.F. had with it was as the flying testbed for the Iroquois).
By June 1963, Canadiar leased the CL-52 to the R.C.A.F. for $1.00, and was flown (by Canadiar pilots) to CEPE (the forerunner to AETE) in Cold Lake, Alberta for delivery. The R.C.A.F. promptly put the aircraft in testing, and re-designated it 5259.
By 1965, 5250 was given a green and grey camouflaged scheme for its Canadian testing, and had an external drop tank mounted for added fuel for northern testing or trans-Canadian flights.
In October 1976 (now designated 111059), the CL-52 was moved to Bristol Aerospace in Winnipeg, where systems modifications were done, and by January 1977, the aircraft was scrapped and returned to Canadair in Montreal, where it remained until 1985 before Bombardier (Canadair's new owner) donated it to C.F.B. Winnipeg as a display in 1990.