Southwest Airlines is implementing a new safety policy, effective May 28, requiring passengers to keep portable phone chargers and power banks visible during flights when you're charging a device. The airline will prohibit the use of these devices while they're stored in carry-on bags or overhead bins,

That's in addition to the three gateways the two airlines launched earlier this year: Denver International Airport (DEN), Nashville International Airport (BNA) and Baltimore/Washington International Thurgood Marshall Airport (BWI).

Southwest Airlines made the controversial decision to end its longstanding policy of allowing two free checked bags for each customer. However, as the airline implements the policy change this month,