Investigators continue to look into why a helicopter with a student and an instructor aboard crashed shortly after take off from the Venice Municipal Airport this week.
The Federal Aviation Administration now says the chopper was not registered, and therefore could not legally fly in the U.S.
The aircraft is owned by the Helicopter Academy in Fort Lauderdale.
Flight instructor Ronald Vasconcelos and student pilot Agnus Jolumo remain hospitalized.
The Robinson R 22 they were flying was built in 1985.
Last year, the FAA issued a warning about problems with the main rotors on that type of helicopter.
And the one involved in the Venice wreck had crashed once before in California.