The Federal Aviation Administration has extended until March 15 the public comment period on an environmental assessment of a proposed flight path change from Logan International Airport. The FAA has said the airport’s new system, which guides planes departing from Runway 33L with a satellite-based system rather than the current ground air traffic system, would be safer and more efficient. The system would channel air traffic through a narrow corridor over sections of Milton, Randolph, Canton, and Dedham, which stirred up concerns among local officials and residents when the assessment was released Jan. 14. “The extension of the deadline is only important if they actually listen to the input of the public and alter the plan,” said Randolph Town Manager David Murphy in an e-mail. “I would hope that the extension was not issued only to create the impression that the public view point was important.” The change in flight paths was to begin March 7, and a new start-up date has not been set. To review the draft environmental assessment, visit www.bostonrnavea.com.