Part 135 operations are the subject of FAA Notice 8400.83 focusing on clarifying the responsibility for operational control during air-taxi operations and spelling out the limitations of using doing-business-as (DBA) names. The FAA’s director of flight standards sent the June 10 notice to all Part 135 principal operations inspectors, providing them new, more stringent guidance on issuing DBA name authorizations. The notice is believed to be fallout from the investigation of the February Challenger crash at Teterboro Airport, N.J. Copies of the notice are available at www.faa.gov/avr/afs/notices/8400/n8400-83.doc.