Frontier Swoops In to Serve Spirit Hubs as Rivals Cut Capacity

While most airlines in the US are cutting back on capacity expansion — or reducing flying overall — Frontier Group Holdings Inc. is going the other way, pumping more seats into the market.

The reason is simple: a week after Spirit Aviation Holdings Inc. ceased operations, Frontier is executing on a strategy its CEO said has been in the works for months, pouncing on market share left on the table after Spirit went out of business.

The airline is adding capacity into airports such as Orlando, Las Vegas and Dallas-Fort Worth, where Spirit had a large presence, according to a ...