CANBERRA, Oct. 28 (Xinhua) -- The Australian Defence Force (ADF) said the doors on its fleet of multi-role Taipan helicopters are not wide enough for guns.

Shane Fairweather, the head of helicopter capability and sustainment for the ADF, told a senate hearing that a third round of works is being undertaken on the MRH-90 Taipan fleet that was purchased from Airbus from 3.8 billion Australian dollars (2.7 billion U.S. dollars).

He told the committee that the doors on the helicopters were too narrow to allow guns while troops are descending from it.

The fault means that the army has had to fly the helicopters in pairs to carry out certain missions, he said.

Defense chief Gen. Angus Campbell said the MRH-90 Taipan was an "extraordinary helicopter" but conceded the fleet has problems.

"I would like a perfect helicopter, it would be all things to all people," he said. "It requires a careful planning of the employment of our aircraft. We never fly an aircraft on its own."

It comes after the army's entire fleet of 47 MRH-90s was grounded briefly in 2019 to address tail rotor vibration.

Army chief Rick Burr told the senate hearing that "tactical workarounds" were enabling the helicopters to complete their duties despite the door issue.

"There are some technical issues and safety issues that prevent that from occurring but there are tactical workarounds that are in place," he said.