Abstract: Aspects of the disclosure provide methods for determining a likelihood of failure of an aerial vehicle. In one instance, the method may include receiving a first rotation rate of an impeller of an altitude control system of the aerial vehicle. A model may be used to determine a second impeller rotation rate, wherein the second rotation rate is an idealized impeller rotation rate. The first rotation rate may be compared to the second rotation rate. Based on the comparison, the likelihood of failure may be determined.

Abstract: Aspects of the disclosure relate to processing sliding mechanisms. For instance, an assembly including a first component having a first sliding mechanism may be heated to a first minimum temperature for a first minimum period of time. Thereafter, a second component is pressed onto the assembly a first time such that the second component contacts the first sliding mechanism. Thereafter, the second component and the assembly may be subjected to a below-freezing temperature for a second minimum period of time. Thereafter, the second component may be separated from the assembly. The first sliding mechanism may be rotated relative to the first component. Thereafter, the second component may be pressed onto the assembly a second time such that the second component contacts the first sliding mechanism. Thereafter, the first component and the assembly may be heated to a second minimum temperature for a third minimum period of time.

Abstract: An antenna assembly according to one embodiment is configured to be installed and fixedly mounted to a vehicle body wall after being inserted into a mounting hole in the vehicle body wall from an external side of the vehicle and nipped from the interior compartment side. The antenna assembly may include a composite antenna base, which may be operable as a primary load-bearing structure for transferring loads associated with the antenna assembly to the vehicle body wall. The composite antenna base may integrally define means for mounting a printed circuit board without using mechanical fasteners. The composite antenna base may integrally define one or more resiliently flexible retention members for helping retain the relative position of the composite antenna base to the vehicle body wall before the antenna assembly is fixedly mounted to the vehicle body wall.