Regional NSW carrier Brindabella Airlines is feared to be in a precarious financial position now that eight of its 10 aircraft are grounded by the Civil Aviation Safety Authority for maintenance reviews.

Commonwealth Bank of Australia has a fixed and floating charge over the airline's assets and forensic accounting firm KordaMentha is understood to be closely monitoring the situation on behalf of the bank.

Brindabella has licences to operate as the monopoly carrier on key regional NSW routes providing services between Sydney and the towns of Cobar, Moree, Mudgee, Narrabri and winter-only services to Cooma. Its aircraft seat between 18 and 30 passengers.

The Canberra-based airline's owners, Business Air Holdings, have not lodged accounts with the corporate regulator in recent years. The airline has been reported to be behind on its bills to some local councils but executives could not be reached for comment.

Qantas Airways last month revoked a codeshare with Brindabella after CASA initially grounded four of its Jetstream planes because engine inspections were overdue. Two of those aircraft are now back in service, but CASA on Thursday grounded a further six Jetstream and Metroliner planes.

Transport for NSW said it was working on alternative transport arrangements for communities affected by action taken by CASA including additional NSW TrainLink coach services between those communities and other regional airports.

"[The CASA] action is likely to have significant impact on the airline's schedule on licensed routes," a Transport for NSW spokeswoman said on Friday.

She said Transport for NSW had formally requested Brindabella address concerns surrounding the provision of air services as outlined in its air licence. Transport for NSW cannot recall ever having had to revoke a licence in the past.

Brindabella on Friday said the additional inspections ordered by CASA would "undoubtedly result in some disruption" in its network.

"Brindabella look forward to restoring scheduled services very shortly and apologise to any of its loyal customers who may have been affected," the airline said.

It added flights scheduled to operate on Friday and over the weekend had not been affected. The airline has cancelled dozens of flights in recent weeks and temporarily suspended its services between Sydney and Orange.

The NSW government this week said it would launch an inquiry on the provision of commercial flights to regional centres in NSW.

Brindabella last year beat out QantasLink for a five-year contract providing air services to Moree. A number of community residents were upset at the decision but QantasLink did not appeal it to the Administrative Decisions Tribunal.