New Zealand aviation officials have reported more than 250 safety breaches including a box-cutter, runaway suitcases and unfortunate hedgehogs.

The Civil Aviation Authority has released a list of "incidents" involving planes for the year till October 2015, revealing an array of safety concerns from the bizarre to the scary.

Many involved animals, ranging from three cows on a Gisborne airfield, through to dead hedgehogs on Wellington Airport's Tarmac.

Supplied An inert hand grenade was caught at New Zealand airport security.

Perhaps the most concerning security breach was a box-cutter, the weapon of choice for the September 11 terrorist attacks, found in a passenger's pack during transit screening at Auckland Airport in July last year.

The incident comes about a year after a passenger travelling from Wellington carried a box-cutter onto a plane to Auckland, where it was eventually detected by security.

Other potential weapons picked up by security included an arrow head, a knife with a 10cm blade, and a large pair of scissors found in carry-on bags in Auckland.

Another passenger was caught travelling from Rarotonga to Auckland with a multi-tool, including an 8cm blade. Even a hand grenade, thankfully inert, was found in a passenger bag in Auckland in June last year.

Despite the risks, all passengers caught with potential weapons, from the box-cutter to the hand grenade, avoided prosecution.

As well as risks onboard aircraft, the authority recorded outside aviation risks and accidents, such as bad weather and hedgehogs.

At Ardmore Airport in Auckland in July last year, planes were thrown about in a weather bomb that included mini tornadoes, with one landing on its back and one plane blown on top of another.

Dogs were a common problem on runways around the country, while an errant hare was reported as a safety breach in Hokitika.

In Wellington, dead hedgehogs – usually squashed – were particularly problematic, reported five times in 12 months, although the spiky creatures posed "minimal risk" to planes.

A Wellington Airport spokesman said the reporting of hedgehogs was part of "best practice for reporting all wildlife events at the airport as set in our safety and security procedures".

"Over the course of a year it would not be unusual to have a few hedgehogs walk across the runway."

An Aviation Security Service spokesman said, though most incidents on the list were unintentional, any breach of airport security was taken seriously.

Any obvious attempt to thwart airport security was referred to police, he said.

Passengers should ensure they were not taking items through security that were not allowed.

"Members of the public are reminded not to enter prohibited areas in and around airports.

"Those who are responsible for animals such as pets or livestock need to pay particular attention to ensure their animals do not enter these areas."

AVIATION SAFETY BREACHES

Included on the CAA list of 264 safety breaches for the year to October 2015:

* A passenger who chased a getaway hat across an active taxiway in Auckland

* A passenger in Wellington who put a lit cigarette in their apron while boarding a flight

* An aircraft in Wellington which had to come to a sudden stop to avoid a rolling wheeled suitcase

* Another plane that had to abort takeoff when a plastic bag blew in front of it