According to the FAA advisory, Frontier Airlines has grounded all flights across the US due to IT issues. The FAA advisory notes that "all Frontier Airlines (FFT)" destinations are impacted, but only for departing flights.

IT issues at Frontier Airlines triggered a brief ground stop at all of the U.S. budget carrier's destinations on Thursday evening, according to an advisory from the U.S. Federal Aviation Administration.

Frontier says a merger would be a better path out of bankruptcy for Spirit, as budget carriers struggle with high costs and competition.

Frontier Airlines is again pursuing a merger with Spirit Airlines, with Spirit mired in chapter 11 bankruptcy proceedings.

After months of playing coy, Frontier Group Holdings acknowledged on 29 January having "significant interest" in creating the USA's fifth-largest through the acquisition of ailing ultra-low-cost carrier Spirit Airlines.