Australia’s Civil Aviation Safety Authority (CASA) has extended until at least Feb. 15, 2013 its decision to force Barrier Aviation to cease all operations with its 34 aircraft. The CASA initially suspended the airline’s operations for five days on Dec. 23, 2012. The suspension follows a safety audit of the operator that revealed a range of maintenance-related deficiencies.

In a press release, the CASA said it believes that “permitting Barrier Aviation to continue to fly poses a serious and imminent risk to air safety” and that it had been operating aircraft with “serious and known defects.” Further investigations by the CASA uncovered additional maintenance issues. According to the agency, Barrier Aviation also failed to document defects on its aircraft when they did become known.

The grounding of the Cairns-based operator disrupts flights that are commonly used to carry people conducting important professional functions to and from the northern tip of Queensland, including reef shipping pilots, court officials and doctors.