PURPOSE: To improve steerability during self-traveling of an aircraft and the replaceability of wheels while the aircraft stops by providing a plurality of independent leg struts, a structure member fixed to the structure of the aircraft and a rotatable oscillating lever.

CONSTITUTION: This device is provided with a plurality of independent leg struts 101 juxtaposed parallel to the central plane of the aircraft in lengthwise direction. A pair of wheels R are attached to each top end of these leg struts 101 and each leg strut 101 is provided with a fixed structure member 102. The device is provided with an oscillating lever 103, which can be turned with an axis Y vertical to the central plane of the aircraft in lengthwise direction as a center, hinged to the structure member 102. The oscillating lever 103 is formed so as to move up together with a pair of wheels R by being driven by an actuator cooperated with the leg struts 101. Further, the leg strut 101 is provided with a hydraulic generator 120 provided independently of each leg strut 101. Therefore, even the oscillating lever 103 can partially pull in as well.