Frontier Airlines is offering its Economy Bundle for free on nonstop flights from March 18 to August 18, including a free carry-on, seat selection, and flight changes. From May 28 to August 18, passengers using promo code FREEBAG also get a free checked bag. Bookings must be made by March 24, with fares starting at $39 one-way. Targeting Southwest’s recent policy changes, Frontier aims to win over travelers by bringing back free perks. If demand is strong, the airline may make the offer permanent.