The respondents operated a commercial float plane business on a lake in a municipality.
The municipality amended its zoning by-law to prohibit aerodromes on that lake, while permitting them on another lake.
The municipality sought an injunction to stop the respondents' aviation activities.
The Supreme Court of Canada held that the by-law amendment was ultra vires the province because its pith and substance was the regulation of aeronautics, an exclusive federal jurisdiction.
The Court further held that the amendment was not saved by the ancillary powers doctrine because it was not rationally and functionally connected to the broader, valid municipal zoning scheme.
The appeal was dismissed.