An aviation expert on Monday said rising fuel costs and booming passenger taxes remained tough challenges for some of South Africa's budget airlines.
Last week several Velvet Sky flights were delayed and cancelled due to problems with its service providers.
Velvet Sky bosses have since assured passengers not to worry about the company's long-term sustainability.
SA Flyer Magazine editor Guy Leitch said it was difficult to fully establish the financial resources of the owners.
"We don’t know how much commitment and money it’s got to keep it going and the airline can’t be expected to make money for at least another year or two."
Leitch said while One Time Airlines feels the pinch, other more established airlines are doing considerably well.
“Kulula should be alright. It flies modern Boeings which are 25 percent more fuel efficient than other airliners. We think Mango is fine too."
(Edited by Lisa Bartlett)