Melbourne magistrate John Doherty told Christopher Parkington's barrister that "in aviation terms ...  if [Parkington] keeps this up he's going to drop a bomb."

Mr Doherty on Thursday had just asked barrister Sam Tovey of his client: "How's he feel about going to prison?"

The sentence was a possibility for Parkington, who pleaded guilty in Melbourne Magistrates Court to four charges of driving while suspended.

Prosecutor Senior Constable Dragos Panoschi said Parkington was caught driving unlicensed four times between October, 2013, and February this year.

Senior Constable Panoschi told the court Parkington's licence had originally been suspended for accumulated demerit points.

Mr Tovey said Parkington, a mortgage broker, was regarded as a reliable and honest man who worked hard and had succeeded in "heavily professional" areas as a pilot and in his present position.

Mr Tovey said it was not an excuse for the conduct and that Parkington's fear of losing his job "overrode his better judgment".

He had taken a "double or nothing" option to not re-offend within 12 months after his licence was first automatically suspended for three months. This was then increased to six months when he did re-offend.

Mr Tovey told Mr Doherty that the possibility of a prison sentence was a reason Parkington has sought legal advice on the charges.

Parkington, he said, accepted he would now spend further time off the road and suffer more pain, adding that the "penny's dropped all too late."

Mr Doherty suspended Parkington's licence for three months and fined him $2500, telling Parkington, of Fitzroy, that but for his guilty pleas he would have been imprisoned.

He told Mr Doherty he understood that any breach of the order would almost certainly end in a custodial sentence.