AOPA Australia President Andrew Andersen has resigned from the AOPA board, effective immediately.
Andersen's departure is thought to be due to pressing business commitments.
Former president Phllip Reiss has agreed to take over as interim president until the Annual General Meeting in April.
"Andrew has done a great job as President during his 14 months term," Reiss said, "however, dividing his time between business commitments and this voluntary role has become increasingly difficult.
"I would like to personally thank Andrew for his board participation and the great work he has done on the ASTRA Council; had it not been for Andrew's representation on this council, the introduction of ADS-B would have had considerable impact on general aviation."
Andersen brought significant regulatory and technical abilities to the board, and his resignation leaves a void that AOPA will need to fill quickly.