Frontier Airlines will fly larger airplanes out of Trenton-Mercer Airport in Ewing Township this spring. The Denver-based carrier is replacing its 150-seat Airbus A-319 aircraft with 186-seat Airbus A-320 planes out of the state's second-busiest general aviation and corporate jet airport, after Teterboro.

Frontier is retiring the A-319 fleet to operate larger more fuel-efficient A-320s in Trenton. The new planes will be phased in between March 14 and April 21, said airline spokesman Jim Faulkner.

Frontier adjusts schedules seasonally to fly to warm-weather destinations in the winter and more cold-weather locales in the summer. The airline will fly nonstop this spring and summer from Trenton to Atlanta, Charlotte, Chicago O'Hare, Detroit, Fort Lauderdale, Orlando, Tampa, Punta Gorda, and Raleigh Durham, N.C.

Frontier also flies out of Philadelphia International Airport to Charlotte, Cancun, Denver, Orlando, Miami, New Orleans, Punta Gorda, Punta Cana, Raleigh Durham, and Tampa.

Frontier operates some routes daily, but others two or three times a week. That requires fewer crews and planes are full.  Frontier caters to leisure travelers and customers who can be flexible about their travel dates.

Frontier's strategy is much like Spirit Airlines and Allegiant Air, which offer low base fares but charge for everything on the flight, from soft drinks to carry-on bags in the overhead bin.