Mango, the low-cost subsidiary of South African Airways, will take over two domestic routes formerly operated by 1time Airline, which filed for liquidation and suspended operations on 2 November.
Once daily direct flights to Port Elizabeth from Cape Town and Johannesburg will be introduced to Mango's route network on 5 December.
"There is a requirement for a low-cost carrier on the Johannesburg-Port Elizabeth and Cape Town-Port Elizabeth route, and with the recent exit of capacity Mango has brought forward its plans by a few months in order to accommodate market demand," says chief executive Nico Bezuidenhout.
The two routes will be operated with leased-in aircraft "until early next year, when Mango expects to add additional capacity to its own fleet", a statement reads.
Bezuidenhout told Flightglobal earlier this month that the carrier had already planned to grow its six-strong fleet by "a minimum of one and most likely two" Boeing 737-800s over the next year, adding that those plans will be likely be scaled up in the wake of 1time's collapse.
He also said Mango is expediting its plans to launch flights outside of South Africa's borders, targeting unspecified east African destinations "within a 12-month period".