The NTSB decision was based on Martz's appeal of his license revocation by the Federal Aviation Administration in March.
Martz has been disciplined by the FAA several times, starting in 1986 when his license was revoked after the agency discovered he had a fraudulent medical certificate. In 2002, his license was suspended and in 2003 it was revoked, both times for "careless and reckless" flying. In June 2005, his license was suspended again for "careless and reckless" flying for 230 days.
In February, a helicopter flown by Martz was forced to land at Van Nuys, Calif., after allegedly flying too close to a Los Angeles Police Department helicopter. When police met him 10 minutes after landing, he was drinking vodka with rock star Tommy Lee, who had been a passenger on the helicopter.
In its decision, the NTSB pointed out that both Martz and Swede had unfastened their safety restraints and her body blocked access to controls that Martz would have needed in case of an emergency.
"During substantial portions of the flight in question, it appears to this board that the flight was but a single misstep from disaster," the decision said.
Martz can appeal the decision in federal court immediately or apply for reinstatement in one year.
