GAS TURBINE ENGINE

The disclosure relates to a gas turbine engine (10) for an aircraft comprising: an engine core (11) comprising a turbine (19), a compressor (14), and a core shaft (26) connecting the turbine to the compressor; a fan (23) located upstream of the engine core, the fan comprising a plurality of fan blades mounted for rotation about an engine axis, each blade of the plurality of fan blades having a leading edge and a trailing edge extending across a span of an airflow duct from a blade root to a blade tip; and a gearbox (30) that receives an input from the core shaft (26) and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft, wherein the trailing edge of each blade is characterized by a metric M defined as a rate of change of an angle of the trailing edge between 0.4 and 0.8 of the span divided by an area averaged trailing edge angle, M being not less than around 4.