• Rotational speed has a greater impact on total power loss than oil inlet temperature in accessory gearboxes.
• Bevel gears and input shaft bearings are the primary contributors, accounting for nearly 50% of total power loss.
• The MPS method effectively calculates flow fields and convective heat transfer coefficients in gearboxes.
• A combined MPS and finite element thermal network approach balances accuracy and efficiency for temperature field prediction.