Security on domestic flights is too strict and should be downgraded, says the head of the Aviation Security Service.

General manager Mark Everitt, a former police detective with 21 years' experience, said if he had his way passengers would be able to take Swiss Army knives and other small, sharp objects on board domestic flights.

"I'm actually an advocate for letting these things back on the aircraft. It's time to back up a little," he told delegates at the Police Association's annual conference yesterday.

But New Zealand had to meet international security standards and his personal view was not enough to instigate a review of security standards.

Knowing levels of risk was the key to ensuring flights were safe, said Mr Everitt. The banning of small knives did not stop attacks in the air.

He referred to a case in Melbourne last May where a passenger tried to hijack a Qantas domestic jet with 47 passengers on board using two sharpened wooden stakes.

In the week United States-led forces invaded Iraq, the service was receiving a hoax bomb call every two or three hours, but not one aircraft was delayed. Security experts decided the cost of halting flights far outweighed the actual risk to those on board.

Mr Everitt also voiced displeasure at armed sky-marshals on international flights, saying he would never back an armed service while he was in charge of aviation security.

"If you're going to have someone carrying a firearm, well, that aircraft shouldn't operate."

He was also against armed officers from foreign countries being allowed into New Zealand terminals.

Sky-marshals are not used on flights out of New Zealand, but airlines flying into the country can apply on a case-by-case basis.

- NZPA