is an actuator jack device of the kind shown in fig3 similarly in the case of the external droop 2b of each wing at s b s b there is a supporting device of the type shown in fig1 and 2 and in two planes such as those v b v b a jack device in accordance with fig3 the assembly of internal and external droops on the wings can be controlled manually by the pilot for example during take off approach and landing at the same time as the trailing edge flaps of conventional design which have not been shown here moreover automatic control is provided in order to extend the droops in the event that too high an angle of attack should give rise to the risk of a stall in the preferred device which will be described hereinafter this automatic control applies only to the external droops 2b which are more effective in controlling stalling the assembly of the control device has been shown schematically in fig5 a line 20 is permanently connected to the source of high pressure oil not shown but located to the right of the figure this line communicates permanently with the lines 18 of all the droop jacks so that the small areas of the.