Kauai police say Tuesday's fiery crash killed the pilot, 54-year-old Gerry Charlebois, and Mark McKenzie, a 53-year-old resident of Pickering, Ont.
Federal Aviation Administration spokesman Ian Gregor says the aircraft crashed on the side of a mountain.
The National Transportation Safety Board is investigating the cause of the crash.
The aircraft —an Evolution Trikes Revo — is registered to Birds in Paradise LLC, a company founded by Charlebois that markets itself to visiting travellers. Federal regulations prohibit the aircraft from being used for tours or thrill rides.
The company advertises scenic flights for tourists described as introductory flight lessons rather than aerial tours.
FAA regulations allow commercial use of light sport aircraft only for flight training or to tow a glider or an unpowered ultralight aircraft.