Garuda Indonesia's crash pilot Marwoto Komar will be offered his old job back if he escapes manslaughter charges over the airline tragedy, the company's chief executive has revealed.

Captain Marwoto, who faces seven years' jail for deliberately crashing the Boeing 737 flight on March 7 last year, killing 21 people including five Australians, has expressed a desire to fly again.

Chief executive Emirsyah Satar said Garuda was footing the legal expenses for Captain Marwoto's manslaughter defence, although the pilot technically is no longer on staff, having been put on contract after criminal charges were laid.

"If he is to fly again, I guess we will just have to follow the process," Mr Satar said in a rare and expansive interview.

Garuda's chief safety officer, Novianto Herupratomo, said if Captain Marwoto - "whose current status is grounded" - were in a position to ask for his full job back, he would be required to undergo extensive psychological and other testing.

"(In a case like that,) if they cannot perform, then we just have to say 'I'm sorry'," Captain Novianto said.

Garuda had, immediately after the disaster, changed some of its basic operating rules for pilots, including specifying that a first officer was required to seize control from the pilot in charge if they believed the plane was not being flown correctly, Captain Novianto said.

Co-pilot Gagam Rohmana was criticised for not insisting Captain Marwoto perform a "go-around" manoeuvre - aborting the landing and lining up again - in the face of 15 automated cockpit warnings and a too-fast approach to Yogyakarta that did not conform with the flight plan filed by the crew in Jakarta.

Captain Novianto said it had now been written into the company's standard operating procedure that "if the pilot is not sure he should make a safe landing, if any monitoring pilot sees that the aircraft is not stable, the co-pilot may override the pilot in command. He should take over."

That rule was being enforced in simulator training, Captain Novianto said.

Mr Satar said Garuda had "no control" over recommended improvements to the Yogyakarta airport, including lengthening the runway, which had still not been done.

He hoped Garuda would be allowed back into European airspace in time for the delivery of 10 Boeing 777s in 2010.

A European Union directive last year banned all Indonesian airlines from member countries' airspace, a decision Mr Satar says he was working on with Indonesia's civil aviation authority to have overturned.

Australian funding for improved safety audit procedures in Indonesia was part of this drive.

However, Mr Satar said that with about 50 commercial operators in Indonesia, running a total national fleet of 228 aircraft, there was a need to merge some smaller operators to guarantee more rigid standards.

Indonesia is one of the world's fastest-growing air markets. Garuda aims to capitalise on this growth by upgrading most of its fleet within two years and expanding its low-cost domestic affiliate airline, Citilink.

Mr Satar said he was interested in expanding Garuda's Australian operations - the company is chasing a projected 6 per cent growth in the Southwest Pacific market.

Australia's Civil Aviation Safety Authority (CASA) had recently reaffirmed its confidence in the operator, he said.

"We had a CASA flight-deck observation in December, which found issues but only minor ones, and we are now waiting for their response to the follow-up actions we have taken," he said.

There was pressure on Garuda to lift pilots' pay in the face of a global skill shortage, despite a recent rise of "more than 10 per cent", he said.