San Francisco's fire chief has explicitly banned firefighters from using helmet-mounted video cameras, after images from a battalion chief's Asiana Airlines crash recording became public and led to questions about first responders' actions leading up to a fire rig running over a survivor. Chief Joanne Hayes-White said she issued the order after discovering that Battalion Chief Mark Johnson's helmet camera filmed the aftermath of the July 6 crash at San Francisco International Airport. Still images from the footage were published in The Chronicle. ... Critics, including some within the department, questioned the chief's order and its timing - coming as...