New Zealand Air Force Hercules C-130 aircraft still flying 50 years on

It's been known as the workhorse of the sky since being introduced to the Royal New Zealand Air Force in 1965.

And while the Hercules C-130 is no fighter jet, there's more to it than meets the eye.

It's hard to enjoy the scenery when you're just 70 metres above ground travelling at 450 kilometres an hour.

'Nocturnal Reach' is an annual proving ground for the members of 40 Squadron to master their craft.

"The crew must learn different skills on how to operate the aircraft in a tactical environment, either a hostile environment or and environment for example if there has been a tsunami or some other disaster where there is no way to land," said 40 Squadron flight lieutenant Jessica Berriman.

While this flight is a dress rehearsal, everybody on the C-130, from the pilots in the front, to the loads men at the rear, are preparing for the real deal.

"That could be how to avoid being detected, so that can involve low-level flying to mask ourselves with terrain and that can also be in the way of how to defeat any threat we come across like small arm fires or missiles. Deployment could come at any time, and it could be to any number of situations" said Berriman.

Today's training mission includes a load drop.

While they're empty crates here, it's a skill that's been used to deliver aid after the Kaikoura quakes in 2016, and on deployments to the Middle East.

The planes have been around half a century - they were delivered in 1965.

And even with upgrades the Hercules are showing their age -  Newshub reported it was taking 50 days to service these planes every 400 flying hours.

They will soon be replaced by a more modern transport aircraft but until then - they'll keep flying.

The Hercules - aging - but still airworthy.