A propulsion engine for an aircraft, the propulsion engine comprising: a first fan having a first set of first blades and a second fan having a second set of second blades, the first and second fans being arranged to rotate about the axis of the engine in opposite directions in operation of the engine; first and second angular pitch adjustment mechanisms which are coupled to the first and second sets respectively and also mutually coupled; and actuation means coupled to the first angular pitch adjustment mechanism; characterised in that the first angular pitch adjustment mechanism comprises (i) a plurality of first cranks each joined directly to or integral with the radially inner end of a respective first blade, (ii) a plurality of first thrust rods each of which couples the actuation means to a respective first crank and (iii) a first unison ring coupled to each of the first cranks and arranged for rotational movement about the axis of the engine relative to the first fan; the second angular pitch adjustment mechanism comprises (iv) a plurality of second cranks each joined directly to or integral with the radially inner end of a respective second blade, (v) a plurality of second thrust rods each having a respective first end coupled to a respective second crank and a respective second end coupled to a first thrust bearing, (vi) a plurality of third thrust rods each of which couples a respective first crank to the first thrust bearing and (vii) a second unison ring coupled to each of the second cranks and arranged for rotational movement about the axis of the engine relative to the second fan; each crank and the blade to which it is directly joined or as the case may be with which it is integral being arranged for rotation about an axis extending radially with respect to the fan of which that blade forms part, the pluralities of first, second and third thrust rods being circumferentially arranged and extending longitudinally with respect to the axis of the engine and the first and second unison rings being co-axial with the axis of the engine, and in that each second thrust rod is coupled to a respective second crank and each third thrust rod is coupled to a respective first crank and to the first thrust bearing such that when the actuation means generates an output, the angular pitch of each of the first blades and the angular pitch of each of the second blades are changed in opposite senses. a first fan having a first set of first blades and a second fan having a second set of second blades, the first and second fans being arranged to rotate about the axis of the engine in opposite directions in operation of the engine; first and second angular pitch adjustment mechanisms which are coupled to the first and second sets respectively and also mutually coupled; and actuation means coupled to the first angular pitch adjustment mechanism; characterised in that the first angular pitch adjustment mechanism comprises (i) a plurality of first cranks each joined directly to or integral with the radially inner end of a respective first blade, (ii) a plurality of first thrust rods each of which couples the actuation means to a respective first crank and (iii) a first unison ring coupled to each of the first cranks and arranged for rotational movement about the axis of the engine relative to the first fan; the second angular pitch adjustment mechanism comprises (iv) a plurality of second cranks each joined directly to or integral with the radially inner end of a respective second blade, (v) a plurality of second thrust rods each having a respective first end coupled to a respective second crank and a respective second end coupled to a first thrust bearing, (vi) a plurality of third thrust rods each of which couples a respective first crank to the first thrust bearing and (vii) a second unison ring coupled to each of the second cranks and arranged for rotational movement about the axis of the engine relative to the second fan; each crank and the blade to which it is directly joined or as the case may be with which it is integral being arranged for rotation about an axis extending radially with respect to the fan of which that blade forms part, the pluralities of first, second and third thrust rods being circumferentially arranged and extending longitudinally with respect to the axis of the engine and the first and second unison rings being co-axial with the axis of the engine, and in that each second thrust rod is coupled to a respective second crank and each third thrust rod is coupled to a respective first crank and to the first thrust bearing such that when the actuation means generates an output, the angular pitch of each of the first blades and the angular pitch of each of the second blades are changed in opposite senses.