RAAF seeks new hot air balloon

The Australian air force is in the market for a new aircraft - but this one won't cost billions and won't be able to bomb people.

Defence is inviting tenders for a new custom-designed hot air balloon system (HABS)for the RAAF, to join the two existing balloons operated by the Central Flying School in Canberra.

"The balloons' primary purpose is to promote a positive air force image. This is mainly achieved by employing the balloons in public relations activities involving free flights, tethered flights and static displays across Australia," the RAAF says in its tender request.

The actual design is top secret.

It will only be revealed when the HABS makes its inaugural public appearance early next year.

So what's a HABS worth?

One Sydney manufacturer advertises a basic model under $30,000. But the new RAAF balloon will certainly be more expensive since it's specifying a custom design "instantly recognisable and associated with the RAAF and the air force brand."

Tenders close early next month.