The company's warning follows a recent announcement by the Airports Company of South Africa (Acsa) that it plans to spend over R20bn to upgrade airports in the country, a cost that kulula believes is way in excess of what is required.
Acsa is one of the most profitable companies in South Africa with a net return on turnover of over 40%, according to kulula.
"We have worked hard over the past six years to get more South Africans travelling by air and in that time the market has doubled in size.
"Our customers are now faced with escalating airport charges that will make flying considerably less affordable," said joint CEO of kulula's parent Comair Limited, Erik Venter, adding that an example of the excessive spending is in Durban where there is a plan to build a new airport at a projected cost of R7bn instead of the much more affordable option of upgrading the existing airport for only R1bn.
There are trends around the world to build much more cost-effective airports to facilitate the affordable growth of air travel. In Malaysia, a special low cost terminal was built at the country's main airport in Kuala Lumpur at a fraction of the cost of the main terminal.
A year ago, kulula commenced operations from Lanseria Airport, north of Joburg, which has had an excellent take up and is more affordable and less congested than OR Tambo International Airport, the company said.
In order to raise customer awareness of the 'runaway' airport charges, kulula.com recently made the controversial decision to separate airport charges from air fares on its website.