Minister of National Revenue v. St. Catharines Flying Training School Ltd., 55 DTC 1145, [1955] CTC 185, [1955] S.C.R. 738 -- summary under Nature of Income

Profits earned by the taxpayer under a contract with the Crown for the training of pilots were by virtue of that contract held on terms that unless the Crown should consent to the accumulated profits being paid over to a non-profit flying club after the termination of the contract, the profits were to be paid to the Crown. Since the profits therefore were in effect held in trust for the Crown, they were not income to the taxpayer.