Engine oil system for an aircraft engine

An engine for an aircraft, the engine comprising:

• a rotational assembly including a bladed rotor;
• at least one oil load including a bearing assembly, the bearing assembly rotationally supporting the rotational assembly;
• a gear box including a gear assembly, the gear assembly coupled with the rotational assembly;
• an engine oil system connected in fluid communication with the at least one oil load, the engine oil system including an oil pump, a heat exchanger, and an oil tank forming an oil flow path of the engine oil system, the oil pump coupled with the gear assembly, the heat exchanger including a primary side and a secondary side, the primary side forming the oil flow path;
• a starter generator coupled with the gear assembly;
• and
• a starter generator cooling circuit having a coolant flow path formed by the secondary side and the starter generator;
• wherein the engine oil system further includes an air cooler further forming the oil flow path, the air cooler disposed downstream of the heat exchanger along the oil flow path;
• and
• wherein the engine oil system further includes a first bypass valve, the first bypass valve disposed between the heat exchanger and the air cooler along the oil flow path, the first bypass valve operable in a first state or a second state, in the first state the first bypass valve directing engine oil through the first bypass valve to the air cooler, in the second state the first bypass valve directing the engine oil through the first bypass valve to the oil tank.