Crew on board the C-130 Hercules this morning said they had suffered a loss of cabin pressure and there were reports of smoke in the cockpit.
The plane with 17 people on board then flew at low altitude and dumped fuel before landing safely, despite a small amount of blue smoke.
Fire service spokesman Jaron Phillips said all emergency crews were stationed at the RNZAF airbase at a safe point.
A spokesman for Defence Minister Gerry Brownlee said that the aircraft was flying north from Whenuapai when it developed pressurisation issues and turned back.
The RNZAF operates five Hercules. It is a large aircraft capable of carrying up to 92 people, although it is also used for carrying freight.
The New Zealand Hercules fleet has recently been modernised, according to the Air Force website, "to ensure they last until 2015".
The original three Hercules in the fleet arrived in the country in 1965. Another two were acquired in 1969.
