The Defence Force is warning that keeping its ageing Hercules transports and Orion surveillance planes in the air is a continuing financial burden.
The government is replacing the Orions with P8 Poseidons from 2023. An announcement on what will replace the Hercules is expected soon.
But in the meantime, the Defence Force is searching for a new company to source about $11 million worth of spare parts annually for the Hercules and Orion fleets.
Group Captain Wally Butt said any delays to buying the Hercules' replacements will only boost the cost of keeping the existing fleet in the air.
"If decisions are deferred around the C130 we're confident we can keep the aircraft flying, albeit this comes with an increasing cost. It's not an exponential growth but certainly there is a double digit factor in terms of the increasing cost," he said.
A contract will probably be signed in the next few months for a new supply of parts.