But Mark Rindfleish, Jetstar chief pilot, told the authority that during the cruise part of the flight there was opportunity for rest or meal breaks.
Mr Greenslade agreed this was possible, but maintained that during the turnaround period he was prevented from leaving the aircraft, and this breached part of his contract.
Jetstar said meal breaks could happen when one pilot controlled the aeroplane and the other had a break.
ERA member Eleanor Robinson said Jetstar was required to comply with mandatory rest breaks, and Mr Greenslade was provided with adequate food at appropriate times of duty.
Ms Robinson ruled that Jetstar did not act in breach of the duty of good faith towards Mr Greenslade.
The New Zealand Airline Pilots' Association took the case to the Authority on Mr Greenslade's behalf.
A spokesman for the Association said it would be appealing the decision.
He could not comment any further on the case or whether it had wider implications on other pilots because of the appeal.
Jetstar said in a brief statement it took fatigue management very seriously.
"The airline has robust safety policies and processes in place to manage fatigue for all team members in line with regulatory requirements."
Air New Zealand refused to answer questions about its breaks policy, instead issuing a two-line statement.
"The employment contracts of our pilots comply with both Civil Aviation Authority requirements and the collective agreements we have in place with our pilot community."