John Locher, The Associated PressThis 2015 file photo shows travelers using a charging station at McCarran International Airport in Las Vegas. By Andy Pasztor, Dow Jones Newswires Federal regulators are leaning toward allowing airline passengers to routinely make phone calls during flights—so long as travelers are warned in advance about potential midair distractions. Proposed rules released on Thursday by the Transportation Department envision leaving it up to individual carriers to determine if they want to permit voice calls using onboard Wi-Fi systems, which are becoming more sophisticated.