Every hot air balloon in the country is to undergo urgent safety checks.
The maintenance inspections of over 70 balloons have been prompted by a preliminary report which says a balloon that crashed and killed 11 people in Carterton last month may not have been airworthy.
The Transport Accident Investigation Commission investigation has found a number of safety checks had not been followed by the balloon operators, Early Morning Balloons.
The commission said strength tests on the balloon structure were not correctly carried out, burner and fuel system inspection rules were not met, and the log book failed to show all airworthiness directives were assessed.
"If I had known as a person getting into the balloon that maintenance requirements had not been complied with obviously personally, I wouldn't want to get in the balloon," said chief commissioner John Marshall.
However, the commission stressed it was too early to say whether maintenance issues actually contributed to the accident and the investigation into the incident is ongoing.
"They've interviewed for example the person responsible for maintaining this balloon and with all of this information these concerns have arisen," Marshall said.
The owners of Early Morning Balloons have previously said all their balloons were inspected and certified.
The Civil Aviation Authority said it's investigating the maintenance practices of the balloon in question and 73 others nationwide.
The Authority says it is acting swiftly to address any deficiencies and will report back next week.
All on-board killed
All 11 people on board the balloon, piloted by Lance Hopping, were killed on January 7 when it caught fire and plummeted into a field at Clareville near Carterton.
Marshall confirmed that TAIC would be issuing an interim inquiry report within the next few months.
The interim report would aim to describe what happened, ahead of a final inquiry report expected early next year that would analyse why events unfolded as they did, and what might be done to reduce the chance of a recurrence.
"The ballooning community and the wider public can be assured that TAIC will, as it has done with this recommendation, call for action to address any significant issue as soon as it is found rather than leaving it to publication of a final report," he said.
Other balloon operators concerned
The annual Wairarapa hot air balloon festival is due to take place in two weeks but director Martyn Stacey said he is confident the seven commercial balloon operators are meeting the safety guidelines.
"My concern is with this coming out the way it has it could potentially affect commercial operators in terms of potential customers," said Stacey.