Carlsbad's McClellan-Palomar Airport, which will expand commercial service by the end of this month, is on a federal list of more than 30 airports in California with “hot spots” for potential aircraft collisions. Two other airports in San Diego, San Diego International Airport and Montgomery-Gibbs Executive Airport also are on the list. The airport watchdog group Citizens for a Friendly Airport argues that these concerns should have been considered before the San Diego County Board of Supervisors approved contracts allowing the return of commercial flights to Carlsbad. The group has also complained about noise and flight traffic patterns at the airport. The list is intended to publicize situations pilots should be aware of to make air travel safer.