An aircraft gas turbine engine (10) comprises a main engine shaft (22) arranged to couple a turbine (17) and a compressor (13), the main engine shaft (22) defining an axial direction (9). The gas turbine engine (10) further comprises at least one radially extending offtake shaft (27) coupled to the main engine shaft (22), and a radially extending electric machine (25a, 25b) coupled to the radially extending offtake shaft (22).