Two Hercules aircraft back in the air

The Defence Force says two of it's Hercules C-130 aircraft are back in business and another will be operational from Monday.

The entire fleet was grounded for 24 hours for maintenance after a breakdown in Australia this week.

Two other of the ageing aircraft are still in intermediate-level servicing, and won't be back in the air till later this year.

"This is what happens when successive Governments defer decisions and defer decisions, and aren't brave enough to make the big spend when it's needed," Defence Minister Ron Mark said on Thursday.

The C-130s are the workhorses of the Air Force.

Newshub previously revealed last year that, at any one time, more than half of the old Hercules fleet had been grounded due to repairs. .

The Government has commited to spending more than $1 billion to replace New Zealand's five Hercules planes with new C-130J-30 Super Hercules aircraft.

Prime Minister Jacinda Ardern said replacing the old Hercules aircraft is necessary because "without it we just couldn't look after ourselves and our neighbours".