Engineers have inspected and tested a Barrier Air aircraft after its door opened mid-flight while flying to Auckland.
The Piper Chieftain plane left Kaitaia for Whangarei about 4.30pm on Tuesday with six passengers and the pilot aboard, before it then completed a flight from Whangarei to Auckland in "rough weather" with five passengers.
However, as the aircraft approached Auckland Airport its single door opened, alarming those on the flight.
"We must have been over Whangaparaoa when a whole lot of air started coming from the door and it got very loud," passenger James Snowden told ONE News.
Despite repeated requests, Barrier Air CEO Mike Foster has declined to comment to ONE News but an airline spokesperson said engineers have inspected the aircraft and "all due diligence” has been done.
He said the plane has been tested, while passenger accounts of the door "coming ajar" where "overblown".
However, Mr Snowden, who was sitting in the back of the aircraft near the door, said "it was bloody scary".
"The pilot asked how the door looked [during the flight], we said 'okay', but [we] don't know what it's supposed to look like."
Another passenger on board the flight also told ONE News the door had opened mid-air.
"Not fully but enough to cause concern," said the passenger, who asked not to be named.
"I would also say the pilot did a great job and the weather was fairly rough."
Mr Snowden said, after the aircraft landed in Auckland, the pilot opened the door but before doing so "noticed the red handle [was] up which he had previously put down".
The seven to eight seater Piper Chieftain aircraft is described on the Barrier Air website as the fastest plane it operates, is "quick and comfortable", and "perfect for Barrier Air's Kaitaia-Auckland service".
Barrier Air took over flying to Kaitaia from Air New Zealand on April 28, 2015.