South Africa's troubled national airline, South African Airways (SAA), has cancelled some domestic and international flights to save cash, the company said on Tuesday.Some of its flights from Johannesburg to the South African cities of Cape Town and Durban, and the direct flight to Munich, Germany, were among those cancelled.Last month, the airline entered bankruptcy protection."These cancellations represent a responsible strategy to conserve cash and optimise the airline's position ahead of any further capital investment," SAA said in a statement.It said it will be reviewing further "possible flight schedule amendments" over the coming days.