A propulsor (22; 542) for a gas turbine engine comprising: a case (21; 588) including a duct disposed along an axis to define a flow path; a rotor including a row of propulsor blades (64; 592) extending in a generally radial direction outwardly from a hub, the hub rotatable about the axis such that the propulsor blades (64; 592) deliver airflow into the flow path; a row of guide vanes situated in the flow path, wherein a first guide vane comprises: an exterior vane surface extending in a generally radial direction between inner and outer surfaces of a duct, extending in a chordwise direction between a first leading edge and a first trailing edge to define a vane chord dimension at a first span position of the first guide vane, and defining a vane circumferential pitch at the first span position of the first guide vane and an adjacent guide vane; wherein the first guide vane comprises a radially inner length, a radially outer length, and a midspan length, which are projected dimensions between the first leading edge and the first trailing edge when viewed from an angle perpendicular to the engine central longitudinal axis; wherein the first guide vane has a first dimensional relationship defined as LO/LM, LO/LM being greater than 1.05; and wherein the first guide vane has a second dimensional relationship defined as LI/LM, LI/LM being greater than 1.20, characterised in that the first guide vane comprises a generally hourglass shape, wherein the row of guide vanes has a vane solidity defined as VCD/VCP, the vane solidity being between 0.7 and 1.43 at a midspan of the row of guide vanes. a case (21; 588) including a duct disposed along an axis to define a flow path; a rotor including a row of propulsor blades (64; 592) extending in a generally radial direction outwardly from a hub, the hub rotatable about the axis such that the propulsor blades (64; 592) deliver airflow into the flow path; a row of guide vanes situated in the flow path, wherein a first guide vane comprises: an exterior vane surface extending in a generally radial direction between inner and outer surfaces of a duct, extending in a chordwise direction between a first leading edge and a first trailing edge to define a vane chord dimension at a first span position of the first guide vane, and defining a vane circumferential pitch at the first span position of the first guide vane and an adjacent guide vane; wherein the first guide vane comprises a radially inner length, a radially outer length, and a midspan length, which are projected dimensions between the first leading edge and the first trailing edge when viewed from an angle perpendicular to the engine central longitudinal axis; wherein the first guide vane has a first dimensional relationship defined as LO/LM, LO/LM being greater than 1.05; and wherein the first guide vane has a second dimensional relationship defined as LI/LM, LI/LM being greater than 1.20, an exterior vane surface extending in a generally radial direction between inner and outer surfaces of a duct, extending in a chordwise direction between a first leading edge and a first trailing edge to define a vane chord dimension at a first span position of the first guide vane, and defining a vane circumferential pitch at the first span position of the first guide vane and an adjacent guide vane; wherein the first guide vane comprises a radially inner length, a radially outer length, and a midspan length, which are projected dimensions between the first leading edge and the first trailing edge when viewed from an angle perpendicular to the engine central longitudinal axis; wherein the first guide vane has a first dimensional relationship defined as LO/LM, LO/LM being greater than 1.05; and wherein the first guide vane has a second dimensional relationship defined as LI/LM, LI/LM being greater than 1.20,