The FAA issued a cease-and-desist order late yesterday ordering Santa Monica (Calif.) Airport officials to halt implementation of an ordinance banning Category C and D aircraft at the field. Airport director Robert Trimborn sent a letter on April 10 to airport users advising them that after today (April 24), “only aircraft in the FAA-designated A and B categories will be allowed to operate at SMO.” Category C and D aircraft have approach speeds greater than 121 knots, and the ordinance would affect about 9,000 of the annual 130,000 aircraft operations at SMO. Penalties include misdemeanor prosecution and a fine up to $1,000 “or imprisonment in the County Jail for not more than six months, or both,” according to Trimborn’s letter. The FAA’s cease-and-desist order noted that “we can make a preliminary finding that the City’s ban on operation of these aircraft is likely unlawful.” Having accepted federal money, the airport cannot deny Category C and D aircraft operators the right to use the airport, the FAA said.